The dispensary category was based on self-reporting by dispensary staff in call verification

If the dispensary had any online activity within the past month , it would be considered active1 . After removing inactive businesses, businesses not selling marijuana, and businesses without storefronts during the verification procedure, the 2,121 unique records were reduced to 826 businesses . These 826 dispensaries constituted the call-verified, combined database of active brick-and-mortar dispensaries in California. Validity statistics, including sensitivity, specificity, positive predictive value , and negative predictive value were computed for each of the four secondary data sources when applicable. Definitions and calculations were described in Technical Note S1. To compute validity statistics, a gold standard must be defined that can identify the “true positive” and the “true negative”. Field census is typically considered the gold standard in retail outlet research. However, it is infeasible in this study due to budget and time constraints for a statewide census. Two gold standards were adopted alternatively to answer the two research questions. To answer the first question regarding the validity of online crowd sourcing platforms in enumerating licensed brick-and-mortar marijuana dispensaries, the first gold standard was whether a record was listed in the BCC state licensing directory . To answer the second question regarding the validity of state licensing directory and online crowd sourcing platforms in enumerating active brick-and-mortar marijuana dispensaries, the second gold standard was whether a record was included in the call-verified, combined database of active dispensaries . We must also define a test that can identify the “positive test” and the “negative test” in validity statistics calculations. Two tests were conducted. The first test was whether a record was present in a given data source after online data cleaning . We used this test to examine the validity of using a single data source with simple online data cleaning for dispensary identification,vertical farming supplies an approach requiring moderate resources.

The second test was whether a record passed call verification; in other words, whether the record was verified to be an active brick-and-mortar dispensary . We used this test to examine the validity of using a single data source with simple online data cleaning plus call verification for dispensary identification, an approach requiring much more resources. To illustrate these validity statistics in the context of this study, we provide an example below . In this example, the data source of interest is Weed maps, the gold standard is whether a record on Weed maps was present in the BCC state licensing directory, and the test is whether a record was present on Weed maps after online data cleaning. Sensitivity measures the probability of a record present on Weed maps conditional on the record being included in the BCC directory, calculated as the number of records that were present on both Weed maps and the BCC directory divided by the number of records present on the BCC directory. Specificity measures the probability of a record absent on Weed maps conditional on the record being excluded from the BCC directory, calculated as the number of records that were neither present on Weed maps nor present on the BCC directory divided by the number of records excluded from the BCC directory. PPV measures the probability of a record included in the BCC directory conditional on the record being present on Weed maps, calculated as the number of records that were present on both Weed maps and the BCC directory divided by the number of records present on Weed maps. NPV measures the probability of a record excluded from the BCC directory conditional on the record being absent on Weed maps, calculated as the number of records that were neither present on Weed maps nor present on the BCC directory divided by the number of records being absent on Weed maps. You will notice that specificity and NPV cannot be calculated in this example, because we were not able to identify a “true negative”, a record that was excluded from Weed maps and also absent in the BCC directory. In fact, not all validity statistics were applicable to a combination of a gold standard and a test with the current study design . Following tobacco outlet research , we considered validity statistics 0-0.2 to be poor, 0.21-0.4 to be fair, 0.41-0.6 to be moderate, 0.61-0.8 to be good, and 0.81-1.0 to be very good. R Version 3.5.3 was used to calculate 95% confidence intervals for all the validity statistics. We computed overall statistics as well as the statistics by dispensary category and county population size . Locations of call-verified active brick-and-mortar dispensaries in California were mapped with ArcGIS Version 10.5.

A total of 2,121 business records were combined from BCC and the three online crowd sourcing platforms after online data cleaning. BCC, Weed maps, Leafly, and Yelp had 630, 811, 535, and 1,468 records included in the combined database, respectively. The overlaps across the data sources were presented in Figure S1. Only 240 records were present in all four data sources. Following call verification, the 2,121 records were reduced to 826, which were confirmed to be active brick-and-mortar dispensaries. Among the 1,295 records removed during call verification, 56.0% were closed, 4.2% were not open yet, 38.0% were not selling marijuana, and 1.8% had no storefronts . BCC, Weed maps, Leafly, and Yelp had 486, 659, 459, and 471 records included in these 826 verified dispensaries, respectively. The overlaps across the data sources were presented in Figure S2. The 826 records included 77 recreational-only, 65 medical-only, and 684 recreational & medical dispensaries.Table 1 reports validity statistics using the BCC licensing directory as the gold standard. When the test was whether being present on each online crowd sourcing platform after online data cleaning, Leafly had good sensitivity and Weed maps and Yelp had moderate sensitivity . It indicated that 70% of the BCC licensing directory could be found on Leafly. Leafly also had very good PPV , yet Yelp’s PPV was only fair . It indicated that 83% of Leafly records were included in the BCC licensing directory. When the test was whether passing call verification, Leafly still had the highest sensitivity and PPV , and Yelp had the highest specificity and NPV . It indicated that, call-verified Leafly records performed the best for identifying truly licensed dispensaries and call-verified Yelp records performed the best for identifying truly unlicensed dispensaries in this scenario. Table 2 reports validity statistics using the call-verified, combined database as the gold standard. When the test was whether being present in each data source after online data cleaning, Weed maps had the highest sensitivity and BCC, Leafly, and Yelp all had moderate level of sensitivity ranging from .56 to .59. It indicated that 80% of the call-verified, combined database of active dispensaries could be found on Weed maps. Leafly and Weed maps had very good PPV , and Yelp’s PPV was only fair . It indicated that 86% of Leafly records were included in the call-verified, combined database of active dispensaries. When the test was whether passing call verification, sensitivity statistics remained the same as when the test was whether being present in each data source. This was because call-verified businesses in each data source were a subset of the businesses included in each data source before call verification, such that the numerators and denominators for sensitivity calculation remained the same. Yelp had the highest NPV and Leafly had the lowest NPV . It indicated that call-verified Yelp records performed the best for identifying truly not active brick-and-mortar dispensaries.Table 3 reports the agreement between BCC, online crowd sourcing platforms, and call verification in terms of the category of the 630 licensed dispensaries.

Approximately 25% of the licensed dispensaries on Weed maps and 29% of the licensed dispensaries on Leafly posted their category that disagreed with what was approved in the BCC license. Approximately 12% of the call-verified, licensed dispensaries stated their category in call verification that disagreed with what was approved in the BCC license. Most of the businesses that stated an unapproved category on online crowd sourcing platforms and/or in call verification claimed themselves to be recreational & medical when they were only licensed for recreational-only or medical-only. Table S3 quantifies category-specific validity statistics when the gold standard was whether being present in the BCC licensing directory. Leafly had the highest sensitivity in recreational-only and recreational & medical categories and Weed maps had the highest sensitivity in medical-only category,cannabis indoor greenhouse regardless of the definition of a test. Table S4 quantifies category-specific validity statistics when the gold standard was whether being present in the call verified, combined database. When the test was whether being present in each data source after online data cleaning, Weed maps had the highest sensitivity in identifying recreational-only and medical-only dispensaries, yet BCC had the highest sensitivity in identifying recreational & medical dispensaries. When the test was whether passing call verification, Weed maps overall had the highest sensitivity in all three categories. In 2019, California had 16 counties with a population size above one million and 42 counties with a population size below one million. Table S5 reports validity statistics by county population size when the gold standard was whether being present in the BCC licensing directory. Leafly had the highest sensitivity regardless of test definition and county population size. Table S6 reports validity statistics by county population size when the gold standard was whether being present in the call-verified, combined database. Regardless of test definition, Weed maps had the highest sensitivity in more populated counties and BCC had the highest sensitivity in less populated counties. This study is the first to assess the validity of secondary data sources in identifying brick and-mortar marijuana dispensaries across a large state. We reported the validity of online crowd sourcing platforms in enumerating licensed dispensaries and the validity of state licensing directory and online crowd sourcing platforms in enumerating active dispensaries. Regarding the validity of using online crowd sourcing platforms in identifying the BCC licensing directory, all three online crowd sourcing platforms were able to include over 50% records in the BCC directory, with Leafly containing the largest number of licensed dispensaries . These findings suggested that the online crowd sourcing platforms could serve as a reasonable proxy for the licensing directory. It evidences the validity for many existing and future studies to utilize online crowd sourcing platforms for dispensary identification, especially if a licensing system is not open to the public or is updated infrequently.

It should be noted, however, that the dispensary category registered in the BCC directory may be mismatched with the “de facto” category in which dispensaries operated. Over 25% licensed dispensaries on online crowd sourcing platforms posted their category that disagreed with the BCC license and over 10% call-verified, licensed dispensaries stated their category in call verification that disagreed with the BCC license. Particularly, most of such dispensaries claimed themselves to be recreational & medical while they were only licensed for recreational only or medical only. Such disagreement might be intentionally used as a means of attracting customers or be reflective of how dispensaries operate in practice. Regarding the validity of using the state licensing directory in identifying active brick and-mortar dispensaries, over 20% licensed dispensaries did not pass call verification. This indicated that business licenses may not accurately represent businesses’ operation status in reality. For instance, a business may have been closed before its license is expired and a business may not be open yet even though its license has been approved. In the final 826 call-verified dispensaries, 58.8% were included in the BCC licensing directory. This indicated that the BCC directory failed to capture unlicensed dispensaries, which accounted for over 40% of the total active dispensaries in California. Solely relying on a state licensing directory would overestimate active, licensed dispensaries whereby overlook active, unlicensed dispensaries. Regarding the validity of using online crowd sourcing platforms in identifying active brick-and-mortar dispensaries, Weed maps had a nearly very good sensitivity; it contributed 80% of the records in the final call-verified, combined database. It had the highest sensitivity in identifying recreational-only and medical-only dispensaries. It was also the most sensitive database in identifying dispensaries in more populated counties, which were mostly urban areas. The high concentration of dispensaries and intense competition in urban areas may motivate more businesses to promote themselves on this highly visible and popular platform . Leafly had the lowest sensitivity in identifying active dispensaries. It also had the lowest sensitivity in identifying all three dispensary categories. It is likely because the costs of advertising on Leafly were substantially higher than other online crowd sourcing platforms specialized in marijuana .

Rats that were exposed to cannabis smoke were also reported to exhibit a decrease in anxiety-like behavior

Two rats were excluded during the acquisition phase because of the failure of catheter patiency. In the course of the escalation phase, three rats were excluded from the study because of the failure of catheter patiency at the end of the study, and one rat in the vehicle group died unexpectedly during the day of from cocaine self-administration before the study was completed, thus leaving n=6 rats/group for the final analysis. Te exclusion of those data did not affect the results of the statistical analysis.Te present study found that adolescent WIN exposure increased irritability-like behavior in adolescence, which persisted into adulthood, induced cross-sensitization to the locomotor-stimulating effect of cocaine in adolescence, which did not persist into adulthood, decreased the speed of acquisition but not the rate of cocaine self-administration in adulthood, and had no effect on the escalation of cocaine self-administration in adulthood. Overall, these results demonstrate that although cannabinoid exposure in adolescence induces irritability-like behavior and cross-sensitization to the psychostimulant effect of cocaine during adolescence, it does not promote cocaine self-administration once the animals reach adulthood. However, the effect of adolescent WIN exposure on cocaine self-administration in adolescence was not investigated in the present study because the animals reached adulthood by the time they had recovered from the surgeries that were required for self-administration. Reductions of both body weight and food intake were observed during WIN treatment. Although the activation of cannabinoid receptors typically produces an increase in food intake in adulthood,hydroponic drain table accumulating evidence suggests that adolescent exposure to THC or WIN in rats decreases food intake and body weight.

Te increase in water intake during WIN exposure in the present study confirms the role of cannabinoid receptors in homeostatic responses that regulate not only energy homeostasis but also fluid balance. Irritability, anxiety, and dysphoria are key negative emotional states that characterize the withdrawal syndrome in humans, which arises when access to the drug is prevented and contributes to drug relapse. Irritability has also been reported to be greater in adolescents at higher risk for substance use. Irritability-like behavior has also been shown to increase during withdrawal from alcohol and nicotine in rodents. However, to our knowledge, whether early exposure to cannabinoids affects irritability-like behavior has not been studied in animal models. In the present study, we found that WIN exposure induced irritability-like behavior in adolescence and adulthood, suggesting that cannabinoid exposure in adolescence induces long-lasting neurobehavioral adaptations that can persist months after WIN exposure. However, further studies are needed to investigate whether this finding has translational relevance. An alternative explanation is that, despite blind randomization of the subjects to the two groups, the increase in irritability-like behavior that was observed in WIN-treated rats may be attributable to preexisting differences in irritability-like behavior. Further studies are needed to investigate whether this finding has translational relevance. Numerous human studies demonstrate that early cannabis use is associated with greater vulnerability to the later development of drug addiction and psychiatric illness. A recent study reported a pivotal role for cannabinoid receptors as molecular mediators of adolescent behavior and suggested that cannabinoid receptors may be important in adolescent-onset mental health disorders. Chronic adolescent exposure to WIN has also been shown to induce anxiety-like behavior in rats. However, contradictory findings have also been published, with either no change or even a decrease in anxiety-like behavior after cannabinoid exposure in adolescence.Interestingly, a previous study also demonstrated that long-term cognitive and behavioral dysfunction that was induced by adolescent THC exposure could be prevented by concurrent cannabidiol treatment.

Importantly, WIN acts as a full cannabinoid receptor agonist, in contrast to THC, which only acts as a partial agonist. Moreover, cannabis is known to consist of dozens of additional phytocannabinoids apart from THC. Furthermore, different strains of cannabis differ in their THC content, and THC levels in cannabis have increased year after year because of consumer demand, thus making direct comparisons of human data across time and across studies difficult. Nevertheless, we chose this model of early cannabinoid exposure and followed it precisely because it has been shown to induce cocaine cross-sensitization, thus supporting the gateway hypothesis. Further studies are needed to investigate whether the long-term irritability-like behavior that was observed in the present study can be prevented by concurrent cannabidiol treatment or whether adolescent exposure to cannabis smoke induces long-lasting irritability-like behavior in rats. Epidemiological data consistently document that cannabis exposure precedes the use of other illicit drugs. However, epidemiological data cannot provide causal evidence of this sequence. Animal models are particularly useful for studying effects that are related to cross-sensitization because they allow sequential administrations of the studied drugs while controlling for confounding variables. Several studies have reported behavioral cross-sensitization between cannabinoids and stimulants in rodents. WIN treatment during adolescence in rats induces long-lasting cross-tolerance to morphine, cocaine, and amphetamine, potentiates amphetamine-induced psychomotor sensitization, and induces cocaine-induced psychomotor sensitization in adolescence. WIN exposure also leads to increases in methylenedioxymethamphetamine-induced and cocaine-induced conditioned place preference.

In the present study, WIN exposure in adolescence induced cross-sensitization to the stimulatory effect of cocaine in adolescence. However, this effect was no longer present in adulthood when the rats had self-administered cocaine for several weeks, suggesting that cannabinoid exposure in adolescence may increase the psychomotor effects of cocaine during the first exposure to cocaine, but this effect is not necessarily long-lasting. Cannabinoid exposure increased irritability-like behavior and the psychomotor effects of cocaine, but it did not promote the acquisition or escalation of cocaine self-administration. Indeed, we observed the slower acquisition of cocaine self-administration with 1-h short-access to cocaine in male rats with prior exposure to WIN compared with controls. In contrast, a previous study reported a trend toward an increase in cocaine self-administration during the short acquisition phase in female rats with prior exposure to the cannabinoid receptor agonist CP55,940 but not in male rats. However, this study did not discriminate between inactive and active levers, and no difference in cocaine self-administration was observed during the 14-day maintenance phase in either sex. A recent study showed that adolescent WIN exposure caused impairments in an attentional set-shifting task, a measure of cognitive fexibility, in adulthood. An alternative hypothesis is that the slower acquisition of cocaine self-administration in adulthood that was observed in the present study may be attributable to cognitive impairment that slows the acquisition of operant responding. In humans, several studies have indicated that the adolescent use of cannabis can lead to long-term cognitive deficits, including problems with attention and memory. During escalation, no differences were observed between the rats that were exposed to vehicle in adolescence and the rats that were exposed to WIN in adolescence. This suggests that if cognitive impairments affected the initial acquisition of self-administration, then they did not produce long-term deficits. Te model of long-access to cocaine self-administration is one of the most validated animal models of cocaine use disorder and drug addiction in general. This model has been shown to result in all seven of the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition , and seven of the 11 DSM-5 criteria, including most of the criteria that are required for severe use disorder: tolerance, withdrawal, substance taken in larger amount than intended, unsuccessful efforts to quit, considerable time spent to obtain the drug, important social, work,rolling benches hydroponics or recreational activities given up because of use, and continued use despite adverse consequences.

Te present study found no effect of adolescent cannabinoid exposure in the escalation model, suggesting that adolescent WIN exposure may not facilitate the acquisition, maintenance, or escalation of cocaine use in adulthood. An alternative hypothesis is that the effect of cannabinoid use may not be observed on cocaine intake per se; instead, cannabinoid exposure may produce an increase in the motivation for cocaine, leading to an increase in compulsive cocaine seeking. Indeed, prior exposure to another potential gateway drug, alcohol, was found to have no effect on subsequent cocaine self-administration per se but produced greater motivation and compulsive-like cocaine seeking under a PR schedule of reinforcement. However, we observed no differences between the WIN-exposed and control groups in adulthood when we used a PR schedule of reinforcement to examine whether rats with prior exposure to WIN express alterations of the motivation to self-administer cocaine.One limitation of long-term behavioral studies in adolescent rats, including the present study, is that puberty in rats is relatively short. Compared with adults, rats that are allowed to self-administer cocaine during adolescence have been shown to be more vulnerable to cocaine addiction. Unfortunately, in the model of cannabinoid exposure during adolescence , cocaine self-administration can only be studied starting in late adolescence and continuing into adulthood because rats exit puberty by PND60. Because of this limitation, one possibility is that cannabinoid exposure during adolescence may affect cocaine intake in adolescence. Te present results demonstrate that chronic exposure to cannabinoids does not facilitate the acquisition of cocaine self-administration or compulsive-like cocaine intake in adulthood, measured by the escalation of cocaine self-administration and PR responding in a relevant model of cocaine use disorder. These results suggest that cannabinoid exposure per se is unlikely to be causally responsible for the association between prior cannabis use and future cocaine use in adulthood as purported by the gateway hypothesis. However, we found that cannabinoid exposure produced long-lasting increases in irritability-like behavior, which may indirectly facilitate the emergence of social conflicts and other mental disorders that may contribute to the abuse of drugs other than cocaine. Additionally, the cross-sensitization between WIN and cocaine in adolescence—which was not observed in adulthood—may highlight a short-term increase in the vulnerability to cocaine-induced behaviors. In summary, the present results showed that cannabinoid exposure during adolescence in rats produced cross-sensitization to cocaine in adolescence and a long-lasting increase in irritability-like behavior in adulthood.

However, it did not facilitate the acquisition or escalation of cocaine self-administration or compulsive-like responding for cocaine in adulthood.SUD is a chronic, relapsing disease. CM is a behavioral treatment based on operant conditioning principles that involves providing incentives for meeting specified goals or engaging in target behaviors. CM related to SUD treatment generally involves giving patients tangible rewards such as prizes, cash, or vouchers to reinforce goal behaviors, such as abstinence, medication adherence, or greater/continued engagement with treatment. SUD services such as counseling are already a Medi-Cal covered benefit. CM is often intended as a way to improve the outcomes of these services. CM is not a benefit that directly covers a health care screening, treatment, service, or item. Rather it is an incentive, analogous to, for example, incentive payments for members participating in wellness programs to encourage healthy behaviors. The total cash value a patient could receive through CM ranges widely, with a mean of $914.46 and a median of $466 earned. CHBRP has assumed that CM for SUD treatment programs would be allowed for Medi-Cal beneficiaries .Treatments for SUD include residential, inpatient, and outpatient care using behavioral therapy, counseling, and/or prescription medication. Mutual help groups also support those with SUD to achieve and maintain sobriety. CM can be used as an adjunct to psychosocial treatments for SUD or as a standalone behavioral treatment. Descriptions of treatments for stimulant and cannabis use disorder follow. Stimulants are a class of drugs that includes prescription medications to treat ADHD as well as illicit drugs such as cocaine and methamphetamine. Repeated misuse of stimulants can lead to psychological consequences, such as hostility, paranoia, psychosis, as well as physical consequences of high body temperatures, irregular heartbeats, and the potential for cardiovascular failure or seizures. In California, it is estimated that 33% of all admissions to state- and county-contracted SUD programs are for stimulant use disorders – representing nearly 50,000 admissions annually. It is estimated that there are approximately 3,035 deaths from stimulant use disorder in California each year. Cannabis, also known as marijuana, is the most commonly used psychoactive drug in the United States, after alcohol. Acute effects of cannabis use include nausea, vomiting, and abdominal pain, while chronic impacts include cognitive impairment, pulmonary disease, and sleep disturbance.

Criteria counts for each substance were limited to those who indicated ever using the corresponding substance

Beyond being useful for research purposes, researchers have begun to examine the potential of PRS to predict risk for medical outcomes in clinical settings. PRS for coronary artery disease , atrial fibrillation , type 2 diabetes , inflammatory bowel disease , and breast cancer have been found to be as predictive of these diseases as well known monogenic mutations, which tend to be rarer, and could lead to improved screening for larger numbers of individual who are at risk. Individuals in the top 5% of the PRS distributions had ~3 fold likelihood of having CAD, AF, T2D, IBS, or BC compared to the bottom 95%. For obesity, individuals in the top PRS decile were on average 13 kg heavier than those in the bottom decile. These studies demonstrate the potential for identifying individuals at heightened risk for various medical conditions using PRS. Given that AUD is a moderately heritable trait and GWAS for alcohol-related phenotypes are beginning to identify numerous variants associated with these outcomes, PRS for alcohol-related outcomes may be also able to identify individuals at heightened risk of developing an AUD. In the current analysis, we tested PRS in two target samples, a population-based sample and a clinically ascertained sample of families deeply affected by AUD, to evaluate the current state of alcohol-related PRS in relation to AUD and identifying those at heightened risk. We use several discovery samples from large-scale GWAS to create three PRS: a meta-analysis of two GWASs on alcohol-related problems, a recent large scale GWAS of alcohol consumption, and a GWAS for risky behaviors, including alcohol use. We chose to test PRS based on multiple alcohol-related GWAS because multiple lines of evidence indicate alcohol consumption and dependence have only partially shared genetic etiology. Additionally, we include a PRS for general risk behavior as there is robust evidence that the genetic risk for alcohol and other substance use disorders is shared with other disorders and behaviors related to reduced inhibitory control. Similar to recent work for specific medical conditions, greenhouse tables we compare the upper end of the PRS distribution at various thresholds to examine whether focusing on these upper parts of the distribution provide additional information in identifying those at increased risk of developing an AUD.

We acknowledge the exploratory nature of these analyses and the arbitrary nature of our thresholds in the absence of well-defined clinical risk scores, such as those for medical conditions like hypertension. Finally, we test the association of these PRSs with other substance use disorders , based on the robust finding that substance use disorders share an underlying genetic architecture, with the majority of the heritability shared across substances.We constructed lifetime criteria counts of cannabis, cocaine, and opioid use disorders based on DSM-5 criteria. We measured nicotine dependence criteria using the Fager strom Test for Nicotine Dependence , which assesses six criteria and has values ranging from 0 to 10 in both COGA and FT12. Because many illicit SUDs were not measured or rare in the FT12 data, we limit analyses of illicit SUD to COGA. Like AUD, these criteria counts represent the maximum reported for each respondent across the course of the study.In the case of FTND, this is limited to those who report smoking 100+ cigarettes in their lifetime.We created PRS derived from publicly available large scale GWASs. Information on genotyping and quality control is available in the Supplementary information. We created PRS using a Bayesian regression and continuous shrinkage method. PRS-CS uses LD information from an external reference panel to estimate the posterior effect sizes for each SNP in a given set of GWAS summary statistics. Both empirical tests and simulations have shown improved predictive power above traditional methods of score construction. For computational purposes, we limited the SNPS for score creation to HapMap3 SNPs that overlapped between the original GWAS summary statistics, the LD reference panel, and the target samples for score creation. We converted PRS to Z-scores for interpretation. We used four primary discovery GWASs to create three different PRSs. The first was from a recent GWAS of number of alcoholic drinks per week in approximately one million individuals provided by the GWAS & Sequencing Consortium of Alcohol and Nicotine Use. We obtained GSCAN summary statistics with all Finnish and 23 and Me cohorts removed . The PRS for alcohol problems were derived from a meta-analysis of two GWASs: a GWAS on the problem subscale from the Alcohol Use Disorders Identification Test in 121,604 individuals from the UK Biobank and the Psychiatric Genomcs Consurtium’s GWAS of alcohol dependence. Both FT12 and COGA were in the initial AD GWAS and we obtained summary statistics with each cohort removed . Finally, we derived a PRS for risky behaviors from a GWAS of the first prinicipal component of four risky behaviors from 315,894 individuals in the UK Biobank.

While this PRS does include alcohol consumption and smoking, it captures the shared variance between these substance use measures and the other two risky behaviors. These polygenic scores covered the domains of alcohol consumption , alcohol problems , and general externalizing .We first identified the predictive power for each PRS in both COGA and FT12 using the change in R2 above a baseline model with sex, age of last observation, the first ten ancestral principal components , genotyping array, and data collection site . We used linear/generalized-linear mixed-effects models with random intercepts to adjust for clustering at the family level and a pseudo-R2 for mixed models. In addition to the predictive power of individual PRS, we estimated the conditional effect of all PRS on AUD criteria to examine whether each PRS explained unique variance in AUD criteria. We also calculated the area under the curve of the conditional model containing all continuous PRS to estimate sensitivity/specificity. AUC provides an estimate of the probability a randomly selected case has predicted value more extreme than that of a randomly chosen control. An AUC of 0.5 indicates that a classifier does not provide any useful information in determining cases from controls . We next divided PRSs at several thresholds to examine whether there was a non-linear increase in risk of AUD across the PRS continuum. Finally, we compared mean values of other substance use outcomes for the top 5% in each PRS to those in the bottom 95%. We selected this threshold based in the increased prevalence of AUD in those in the top 5% of the PRS distributions . All code is available upon request from the corresponding author.In order to estimate whether individuals at the extreme end of the PRS distribution were at elevated risk of AUD, we compared the risk of AUD between those above and below a given threshold in the distribution. We divided these PRSs at the 80th, 90th, and 95th percentile in each sample and estimated the odds ratio for AUD in the top portion of the distribution relative to the bottom portion of the distribution . Table 2 provides the estimates for all of those models. Across each threshold for AUD severity in COGA, we observed a similar pattern where, as expected, those in the upper end of the polygenic distribution had greater odds of meeting criteria for AUD. However, regardless of the threshold, the OR’s at each threshold were roughly equivalent. For example, in the case of severe AUD, when dividing 80th percentile , 90th percentile , or 95th percentile , all of confidence intervals for the point estimates overlap. In FT12, there was a similar pattern. Though some of the point estimates appear to increase as the thresholds become more restrictive,vertical farming the confidence intervals again overlap.Researchers have begun to evaluate the potential for use of PRS in clinical settings. In this analysis, we examined the current predictive power and strength of association between several PRSs and a variety of SUDs, with a focus on AUD in both a clinically ascertained and a population-based sample. We were interested in which scores based on available GWASs provided the strongest association with alcohol use disorder, whether these scores explained unique variance in AUD in a conditional model, and how well these scores discriminated between cases and controls; what the risk of AUD was for those at the upper end of the risk continuum compared to the bottom; and 3) the levels of substance use disorder criteria for individuals at the top 5% of the polygenic score continuum compared to remaining 95%.In terms of which polygenic scores were the most predictive, we considered three scores: one based on problematic alcohol use , one based on alcohol consumption , and one based on general risky behaviors , as twin and family studies have shown alcohol and other risk behaviors to be genetically correlated traits. In both samples, the GSCAN DPW PRS was the most strongly associated, followed closely by the RISK PC PRS. When we included all of the PRS in one model, all three PRS were associated with AUD criteria in COGA. Only the RISK PC and GSCAN DPW PRS were associated with AUD criteria in FT12.

Overall, the unique contributions of each PRS reinforce the notion that the genetics of AUD are multifaceted, comprised of risk for level of consumption, alcohol-related problems, and behavioral disinhibition. Evaluating the AUC for the combined PRS revealed the combined effect of PRSs only marginally improved the AUC, similar to recent analyses for coronary artery disease and ischemic stroke. We ran a series of sensitivity analyses to test whether differences across the samples reflected age differences rather than differences in ascertainment. Restricting COGA to participants under 30 did not fundamentally change the results . Evaluating the AUC for the combined PRS revealed the combined effect of PRSs only marginally improved the AUC over models with just covariates. In an exploratory approach, we chose a series of more restrictive thresholds to divide the PRS distribution. The odds of having an AUD were statistically indistinguishable across each of the thresholds in both COGA and FT12. Even though the point estimates increased in some cases, the confidence intervals around these estimates were relatively large and they did not differ significantly. Additionally, there were only a small number of individuals in the severe category in FT12 and we urge caution in interpreting these estimates. Finally, the top 5% of the continuum for each PRS reported elevated rates of other SUD criteria compared to the bottom 95%. The RISK PC PRS was most associated with higher mean levels of SUD criteria, suggesting that risk for externalizing may be particularly useful in identifying individuals at risk for multiple SUDs. These initial findings suggest the current PRSs are unlikely to prove useful for SUDs in a clinical setting. Being able to eventually identify those at heightened risk for SUDs may allow for more targeted early intervention and prevention. However, before this is possible, larger discovery GWAS across substance use phenotypes with PRS that explain greater portions of the variance will be necessary. As GWAS sample sizes for SUDs increase, we will likely see increases in effect size. Additionally, using multivariate techniques to model the shared genetic architecture across existing SUD GWAS to include both aspects of externalizing and internalizing may also improve prediction. Inclusion of genetic data in a clinical setting will also require that psychiatrists and clinicians receive greater training in genetics and/or that they partner with genetic counselors, so they are both better able to understand what increased genetic risk means and be able convey that information accurately to their patients. In addition to clinical utility, we must ensure that regulations and protections surrounding the use of genetic information in clinical settings can adequately protect the rights of individuals who are identified to be “at risk.” This research has several important limitations. First, all analyses were limited to individuals of European ancestry because the discovery GWASs available were conducted in individuals of primarily European ancestry. It will be important to ascertain sizable samples of subjects with non European ancestries to properly estimate the predictive utility of PRS in non-European samples. This is especially important for racial-ethnic minorities so that health disparities are not further perpetuated. Second, our use of lifetime diagnoses may obscure the impact of changing genetic influences on the development of AUD across the life course.

No little cigar or cigarillo items were found at schools in upper income communities

However, these effects of WIN on body weight were transitory, as the difference in females did not persist into adulthood. For the behavioral assessments, female subjects were overall more resistant to the long-term effects of adolescent drug exposure. Group differences were only found in the sucrose consumption test, in which the moderate dose WIN females exhibited decreased natural reward consumption compared to the control females. However, differences from the control were not found with the female nicotine and WIN co-exposure condition for sucrose consumption, suggesting that the presence of nicotine ameliorated the actions of WIN on reward circuitry during the adolescent period. In contrast, adolescent exposure to a low dose of WIN had no effect on physiological or behavioral measures, either alone or in the presence of nicotine, for both males and females. Taken together, these findings demonstrate that while adolescent cannabinoid agonist exposure at a moderate dose exerts variable effects on both physiological and behavioral measures in males and females, co-administration of nicotine surprisingly counteracted some of these effects by normalizing to control levels.While prior studies have examined the effects of adolescent exposure of either nicotine or WIN alone on later behaviors, the current findings represent the first examination of the effects of co-exposure during mid-adolescence and subsequent long-term effects on adult behavior. This age range was selected based on the correlation to human adolescence with higher levels of experimentation and more recurrent patterns of drug consumption than that found in younger individuals. With regard to nicotine alone, opposing effects have been found in male Sprague-Dawley rats with increased depression-associated behaviors, vertical outdoor farming but no difference in anxiety-associated behaviors, during adulthood.

However, these behavioral differences were only found at higher nicotine doses approximately twice that administered in the current study. Chronic exposure approaches with a mini pump or nicotine patch at higher doses have also demonstrated decreased exploratory activity, decreased food consumption under anxiety-related conditions, and deficits in contextual condition to shock-associated cues in Sprague-Dawley rats. In mice, adolescent exposure to high dose mini pump has also been shown to disrupt contextual fear condition, but not cued fear conditioning. However, since studies have shown that of those adolescents age 12–17 who smoke, the majority smoke one or less than one cigarette per day, the current studies focused on a rewarding dose with once daily exposure as an investigative goal. Thus, the lack of difference in the behavioral measures with nicotine exposure in the current studies may be attributed to this relatively lower dose administered. Along these lines, it should be noted that this dose was selected based on the rewarding effects of doses in this range, as assessed with the brain reward threshold measure, and behavioral effects elicited in adolescent mice, and thus, the current results have particular relevance to experimental patterns of drug consumption found in youth. With adolescent cannabinoid agonist exposure, findings derived from prior rat studies have been somewhat variable. In one study, adolescent male and female rats treated with the cannabinoid agonist, CP 55,940, exhibited overall increased time on the open-arm of the elevated plus maze, but these effects were not maintained when examining males and females independently, suggesting these differences may have been confounded by baseline differences between the sexes. Since CP 55,940 has high affinity for both the CB1 and CB2 receptors, as well as GPR55, the lack of differences within each sex for drug condition may also have been due to actions on alternate signaling pathways or differences in agonist actions. Interestingly, male Sprague-Dawley rats treated with WIN, the CB1 and CB2 specific agonist, during adolescence exhibited increased depressive-like behaviors in the forced swim and sucrose consumption tests. In our mouse studies, we did not find any differences in these measures with the low dose of WIN and opposing effects at the moderate dose of WIN, indicating that species differences in metabolism and/or genetic heritability factors likely mediate the effects of cannabinoids on adolescent neuro development.

Finally, adolescent WIN exposure has also been found to increase palatable food intake and alter attribution of incentive salience for food reward in adult male Long Evans rats. The increase in natural reward-related effects with adolescent exposure is consistent with our findings at the moderate WIN dose in mice, suggesting cannabinoid exposure during adolescence similarly alters brain reward pathways to enhance subsequent responsiveness to natural reward. Interestingly, Schoch and colleagues also demonstrated increased expression of the endocannabinoids anandamide and oleoylethanolamine in the nucleus accumbens only during a food restricted state with adolescent WIN exposure in rats . Thus, dependent on the availability of food and level of satiety, changes in neural systems regulating reward-related behaviors may be differentially affected in the presence of cannabinoids. Along these lines, it is interesting to note that in the current study, mice were at a satiated level during sucrose consumption, during which time the opposing differences were found in males and females exposed to adolescent WIN. However, during conditions of food restriction, such as during operant food training in the current study, group differences only emerged for males in the reversal task. Thus, altered endocannabinoid signaling may account for this effect during the food restricted state, whereas other mechanisms likely underlie the behavioral differences observed in the anxiety and natural reward-related measures. Cannabinoid and nicotinic acetylcholine receptors exhibit overlapping expression within brain regions implicated in reward-related and affective behaviors, including the prefrontal cortex, ventral tegmental area, nucleus accumbens, medial habenula, interpeduncular nucleus and hippocampus. On the cellular level, both receptors types are expressed on presynaptic terminals and function to modulate release of various neurotransmitters. For instance, with acute administration, both drugs increase extracellular dopamine in the nucleus accumbens and prefrontal cortex , and adolescent cannabinoid or nicotine exposure have also been shown to affect cholinergic, serotonergic and noradrenergic signaling mechanisms. Thus, in consideration of the effects of nicotine and cannabinoids on several neurotransmitter systems and the behavioral findings from the current studies, future studies will need to dissect the differential impact of single or co-drug exposure during adolescence on neural signaling mechanisms. In conclusion, activation of cannabinoid receptors with or without nicotine led to differential sex-specific effects on anxiety- and reward-related behaviors during adulthood. Together, these studies provide evidence that adolescent exposure to drugs of abuse may lead to alterations in affective and cognitive behaviors during adulthood. These data support the conclusion that consumption of cannabis by youth may alter later cognitive function, and thus, policy approaches should be considered to discourage and/or restrict substance use by this vulnerable population.The United States is experiencing an epidemic of lung injury associated with youth electronic cigarette use, or vaping ; in 2018, 20.8% of U.S. high school students reported currently using e-cigarette.

E-cigarette products such as Juul, a popular device that delivers nicotine and flavors,* are used by students at schools, including in classrooms and bathrooms.† Use of flavored e-cigarettes by youths has become an increasing concern . A recent analysis of the National Youth Tobacco Survey showed that among high school students who currently used e-cigarettes, the percentage who used flavored e-cigarettes increased from 65.1% in 2014 to 67.8% in 2018 . In 2018, 8.1% of high school students currently smoked cigarettes, and 45.7% of those students smoked menthol cigarettes. In addition, 7.6% of high school students currently smoked cigarillos, little cigars, or cigars, 43.6% of whom used flavored varieties of these products . Many youths also use cigars to make marijuana blunts , and some use manufactured disposable cannabis products . Waste from e-cigarette products can contain plastics, nicotine, heavy metals, other chemical toxins, and hazardous lithium-ion batteries . The toxicity of combustible tobacco product waste from cigarettes is well established . Cannabis product waste can include plastics, metals, electronic components, and batteries. A garbology study of environmental contamination from e-cigarette product waste, combustible tobacco product waste, and cannabis product waste was conducted using a purposively selected, nonrandom sample of 12 public high schools with a total enrollment of 18,831 students in Alameda, Contra Costa, Marin, and San Francisco counties in California. Using 2016 data from the National Center for Education Statistics,rolling grow table researchers stratified schools by the percentages of students from low-income families .At each school, researchers systematically scanned the student parking lots and exterior school perimeter areas once during July 2018–April 2019 to collect all e-cigarette product waste, combustible tobacco product waste, and cannabis product waste found on the ground. Overall, 893 waste items were collected, including 172 e-cigarette product waste items . Almost all Juul or Juul-compatible pods and caps were found at schools with predominantly middle- and upper-income student populations. Among 74 Juul or Juul-compatible color-coded flavor caps, 73 were from flavored pods other than tobacco flavor. Overall, 47 pod caps were from mintflavored and other menthol-flavored pods. Additional scans were conducted at one upper-income area school beginning 3 months after Juul Laboratories announced it was removing flavors from retail distribution. These additional scans yielded 127 mint, 20 mango, four fruit Juul or Juul-compatible pod caps, and three yellow Juul-compatible caps. At four high schools with populations composed predominantly of lower-income African-American and Latino students, eight e-cigarette product waste items were collected, in addition to 71 little cigar or cigarillo plastic wrappers and mouthpieces, 94% of which were from flavored products.Across all schools, 620 cigarette butts were collected, including 403 from recently smoked cigarettes that were identifiable. Among these, 168 were menthol.

At low, middle, and upper-income schools, identifiable menthol butts accounted for 60%, 38%, and 28%, respectively, of all identifiable cigarette butts. Fourteen cannabis product waste items were found, including vaporizer pens, cartridges, and packaging from high-potency pineapple- and lemon-flavored cannabis oil concentrate vaporizer cartridges. E-cigarette waste and combustible tobacco product waste contaminate the Bay Area high schools studied and confirm use of these products by high school students. Cannabis product waste represents an emerging issue. The large proportions of flavored products identified in this study are consistent with findings from other studies showing high prevalence rates of flavored e-cigarette and combustible tobacco product use among U.S. youths. Further research and actions at national, state, and community levels are needed to inform policy making to reduce youth access to and use of tobacco products, including e-cigarettes, and cannabis products. Youth use of flavored tobacco products, including mint and all other mentholated flavors, is of particular concern. Likewise, measures are needed to eliminate environmental contamination from e-cigarette, combustible tobacco product, and cannabis product waste in and around schools. Schools can engage students in garbology projects to identify existing and new use of these products and to raise awareness about their hazardous health and environmental impacts.As the legalization of cannabis becomes prevalent in the United States, effects from its abuse will result in an increase in emergency department visits.1 We have witnessed a growing trend in our community ED among adolescents abusing a highly potent form of marijuana, butane hash oil . BHO is a concentrated form of tetrahydrocannabinol that is created by using liquid butane as a solvent to extract THC from marijuana plants. As butane is highly flammable, reports of burns and explosions have been reported from the synthesis and use of BHO. A popular trend called “dabbing” involves heating the concentrated oil and inhaling the resultant vapors. These vapors contain very high concentrations of THC, as high as 90% pure. Adolescents may use e-cigarette devices to abuse BHO as a delivery device. Such devices are easily concealed and produce almost no odor, thus leading to the potential for abuse at school and in the home.2,3 Previous case reports have shown BHO abuse may lead to agitation along with neurotoxicity and cardiotoxicity.Since THC may activate serotonin receptors and inhibit serotonin reuptake, its abuse in high concentrations may mimic serotonin syndrome.We present two cases of adolescents with recent “dabbing” use who exhibited signs and symptoms of serotonin syndrome.A 17-year-old female presented to a large community ED by emergency medical services from her home for CoxHealth System, Department of Emergency Medicine, Springfield, Missouri CoxHealth System, Department of Pharmacy, Springfield, Missouri a possible seizure. EMS providers had witnessed agitation, altered mental status, tachycardia, muscle stiffness and tremors in the limbs, and administered 10 milligrams of midazolam intranasally. History was obtained from the EMS providers and the patient’s parents who were present in the room. The patient had been taking sertraline 50 mg daily and had also been prescribed a short course of cyclobenzaprine 5 mg every eight hours, as needed, for “muscle aches.” According to the parents, the patient had taken “a few” but stopped the cyclobenzaprine as it was not effective.

Well managed systems can minimize environmental impacts

Given that the vast majority of participants began drinking during teenage years and must therefore recall multiple decades of alcohol use, estimates of alcohol consumption will naturally deviate from the true amount of alcohol exposure. Consequently, it is recommended that our estimates related to alcohol use and neurocognition be interpreted conservatively with a greater emphasis on directionality than exact magnitude. The cross-sectional nature of our data prevents us from disentangling the effects of alcohol and MA use from longstanding individual differences in neurocognitive capacities . However, the inclusion of the WRAT Reading subtest as a covariate in all regression models increases our confidence that the observed effects of substance use on neurocognitive performance are not attributable to premorbid functioning. Furthermore, the application of demographic corrections to neuropsychological test scores improves the comparison of results between the MA groups despite differences in education. The positive association between WRAT scores and global neurocognition highlights the incremental predictive value of the WRAT above and beyond demographic effects, most notably education. These findings align with prior substance use studies that suggest that intellectual enrichment, as indicated by high IQ, can increase cognitive reserve and mitigate the deleterious effects of stimulant-induced neural injury on neurocognition . Unsurprisingly, MAþ individuals more frequently met criteria for lifetime dependence for other substance use than MA– individuals. However, study exclusion criteria necessitated that such dependence be episodic in nature and remote . Additional individual differences that we were not able to capture in the present study include potential genetic differences in vulnerability to alcohol effects ; however, these would presumably be equally distributed among MAþ and MA– individuals.

The unexpected finding that alcohol reduces the likelihood of neurocognitive impairment in MAþ individuals raises intriguing biologically driven theories of neuroprotection that we unfortunately cannot answer with our data. Simultaneous administration of MA and alcohol versus non-overlapping periods of single substance use is an issue central to conceptualizing the interaction between MA and alcohol use. Many primary MA users report alternating use of MA and alcohol throughout a given binge in order to titrate their subjective experience of intoxication . This coordinated pattern of MA and alcohol use may attenuate MA-related sleep disturbances,indoor hydroponic system but may also increase risky behaviors due to decreased perceptions of intoxication . Although the lifetime average daily alcohol use metric captures lifetime alcohol patterns, it does not capture chronicity and persistence of alcohol use nor does it distinguish periods of concurrent MA and alcohol use from intervals of monosubstance use among the MAþ individuals. Such a distinction between lifetime periods of simultaneous intoxication versus non-overlapping intoxication would permit for a more nuanced understanding of the aforementioned neurophysiological hypotheses. Additionally, although our neurocognitive variables reflect the behavioral outputs of neural functioning, they do not directly measure the integrity of neural circuitry and neurobiological activity. Therefore, the inclusion of genetic, neuroimaging, and fluid-based biomarker data that more directly reflect neurobiological pathways is recommended for future studies of polysubstance use.As of January 2020, recreational use of cannabis is legal in Uruguay, Canada and 12 US states, and medical use is partially or fully legal in 36 countries . As legal markets for cannabis develop, policy makers are tasked to regulate its production, distribution and consumption in new ways. With rising liberalization, researchers have taken a growing interest in the potential environmental impacts of cannabis – a dynamic partly fueled by growing public concerns and news coverage of the topic, which increased by over 500% from 1992 to 2019 . If implemented successfully, legalization could give regulators a chance to anticipate and regulate the environmental outcomes of the cannabis industry as it expands.

Some current regulatory schemes already reflect this priority through the inclusion of specific language meant to reduce environmental impacts which can arise from land, water and energy use, application of chemicals, or other pathways . There are four primary classes of cannabis production which may impact the environment through different pathways and at different magnitudes . These production systems are not always clearly distinct in practice: for instance, in a single farm, mother plants may be kept indoors while cloning occurs in mixed-light and full crops are produced outdoors. Aside from trespass systems , which we describe separately due to the specific practices associated with them, the cannabis production systems we describe can exist legally or illegally. There are distinct trade-offs between production systems. Indoor systems are associated with few concerns about wildlife habitat destruction, water diversion or pollution, but require high external inputs such as energy and fertilizers. Conversely, outdoor farms may require fewer resource inputs, but poor management or siting could disrupt surrounding ecosystems.We note that trespass grows are generally only associated with negative environmental impacts. Researchers investigating interactions between cannabis and the environment have faced historic hurdles – often due to cannabis’ legal status – which include societal stigma, funding restrictions, safety concerns and difficult access related to remote cultivation sites, as well as regulatory obstacles such as complex licensing requirements and restrictions on cultivar testing . Despite such limitations, a new science around cannabis and the environment is starting to emerge. Our objective here is to review existing literature documenting environmental impacts of cannabis, to identify significant research findings and knowledge gaps and to suggest policy recommendations. As shown in Fig. 3, before 2012 only a handful of studies suggested links between cannabis and environmental degradation . Recent empirical studies, however, have started to quantify specific environmental impacts of cannabis cultivation and consumption. While limited in size and scope, this first generation of studies provides an opportunity to identify and summarize both what is known about cannabis and the environment, and what knowledge gaps persist. This review highlights the emerging science around cannabis and the environment. We hope it can serve as a catalyst to encourage more research in this area and as a resource to provide science-based guidance for policy-makers.

We evaluated peer-reviewed and non-peer-reviewed sources that quantified the effects of cannabis cultivation or consumption on the environment. We excluded studies and reports that: addressed other impacts of cannabis such as on human health; focused on other plants or other illicit drugs; or commented on environmental impacts without providing data. Based on published commentaries on cannabis and the environment , we identified a list of terms to search the Web of Science for relevant studies in June-July 2019 . We screened titles and abstracts of resulting studies according to the three eligibility criteria noted above, yielding a total of 14 peer-reviewed articles for which we reviewed the full text. We incorporated nine additional studies referenced in these studies in our final review . We also searched for non-peer-reviewed literature on Google in July-August 2019 and included documents found in the first five pages of results. Our final review includes two non-peer-reviewed reports and a book series . We found six peer-reviewed studies that investigated the water footprint of cannabis cultivation , all of which focus on northern California. Bauer, et al. used satellite imagery to estimate the number of cannabis plants in northern California and used this to predict that watershed-scale water consumption may exceed local stream flow during the growing season. These results were based on assumptions that: on average, a cannabis plant consumes 22.7 liters of water per day throughout the growing season; this water is predominantly accessed through surface-water diversions; and water application equals water extraction. The authors suggested that during dry years, cannabis farming could completely dewater some streams. Butsic and Brenner applied a similar methodology to estimate annual water use for cannabis irrigation at 11,000 m3 – equivalent to 0.001% of annual agricultural water use – in Humboldt County, California.These findings highlight the potential impacts of cannabis on water resources, but their accuracy is limited by a lack of actual water use data. Three additional studies in California examined cultivator-reported water use for cannabis at the farm scale. High variability in water use and extraction practices was documented – likely driven by variation in seasonal growing patterns, farm size or cultivation methods. Wilson, et al. and Dillis, et al. both confirmed that water use rates among California cannabis farmers approximated the 6 gallon per-plant figure reported by Bauer, et al. . However, this was only the case during peak growing season and respondents reported lower water use rates throughout the rest of the year. Wilson, et al. also documented monthly water use on average-sized farms in California and found that while water application to cannabis plants exceeded this rate during cannabis’ growing season,microgreen flood table water extraction from rainwater, surface and sub-surface sources remained far below it for most of the year. In separate assessments of farm scale water extraction practices, Wilson, et al. and Dillis, et al.  showed that sub-surface wells, rather than surface-water diversions, may be the primary source of water for many northern Californian growers. Sub-surface water extraction may threaten connected watersheds if annual extraction exceeds recharge rates, as sub-surface water reserves tend to recover more slowly from overuse than surface sources. We found one peer-reviewed study and one gray literature report focused on cannabis and energy use. Mills estimated that indoor US cannabis production uses 20 TWh of electricity annually, leading to the annual emission of 15,000,000 tons of CO2. This value is equivalent to the energy consumption of the entire US agricultural sector , or to 1% of US total national electricity use.

Mills’ calculations were based on national cannabis cultivation estimates and assumed “typical” energy use for indoor production and relevant transportation processes. A more recent report combined estimated US cannabis demand and cultivation area with self-reported data from cultivators to provide a detailed assessment of current cannabis energy use. Combined illicit and legal cultivation were estimated to consume 4.1 MWh annually, equivalent to 472,000 tons of associated CO2 emissions. These estimates did not account for off-grid energy use, transportation, fertilization or irrigation, but were significantly lower than the numbers reported by Mills . We note that Mills’ findings may not accurately represented energy use by the US cannabis sector today, as cultivation practices have likely become more efficient in recent years. Studies quantifying land-use impacts of cannabis remain scarce despite reports of significant cannabis cultivation activity in North and Sub-Saharan Africa, the Americas and Asia . We found five empirical studies from the US which assessed cannabis and land-use dynamics. Satellite data for California showed a high concentration of cultivation sites in remote, ecologically sensitive areas . In Humboldt County, cannabis’ impact on land cover change from 2000 to 2013 was relatively limited, contributing 1.1% of forest canopy area loss compared to 53.3% from timber harvest . However, remote cultivation sites were linked to landscape perforation as they created gaps in forest patches, reducing forest core areas and increasing open edges. This could contribute to landscape-wide forest fragmentation and resulting wildlife habitat degradation if current expansion rates persist . The spatial distribution of cannabis farms, in addition to total land-use footprint, may thus be significant determinant of potential environmental impacts. These reported spatial dynamics suggest that the factors driving the location of both legal and illegal cannabis cultivation are distinct from those of other crops. Cannabis prices and law enforcement related risks emerged as important factors determining siting decisions in California, Oregon and Washington’s illicit markets . Butsic, et al. documented strong network effects amongst growers in Humboldt County, which led to clustering of cultivation sites and appeared to be more important than biophysical factors such as soil quality or terrain. Klassen and Anthony identified state enforcement capacities and poverty and unemployment rates as potential factors leading to a decline in illegal farms discovered in Oregon, but not Washington, following legalization in both states. Although pesticides used in cannabis production are likely to impact the environment, to our knowledge no quantitative studies have documented these impacts on private land or legal cannabis production systems. We found five peer-reviewed studies which focused on impacts of anticoagulant rodenticides on local wildlife species in trespass grows. ARs are presumably used to control rodent populations; they are frequently encountered on trespass production sites in California and can bio-accumulate in the food chain . In northern and central California, field-studies documented contamination by highly toxic ARs in an endangered predator, the Pacific fisher , using a combination of field-data collection, lab data analysis and spatial correlation .

The last two decades have seen a worldwide liberalization of cannabis production and consumption

Participants were requested to be abstinent from MA for at least 10 days prior to testing and were required to show a negative urine toxicology for any non-prescribed substance except cannabis, as well as a negative Breathalyzer test for alcohol on the day of neurocognitive testing.MA group comparisons of neuropsychological outcomes , demographics, depressive symptoms, alcohol and cannabis use, and other lifetime substance dependence were conducted using Student’s t tests, Wilcoxon Rank Sum tests, chi-square tests, and Fisher’s exact tests as appropriate. MA group differences in neurocognitive performance were evident across domains. Given this nonspecific pattern of MA group differences, and in order to limit multiple comparisons, we present the global T scores and global impairment classifications as outcome variables in linear and logistic regression analyses, respectively. Details of domain-specific results appear in Supplementary Table 2. We first tested whether MA group differences in global functioning were attenuated by differences in estimated premorbid ability and neuropsychiatric factors by entering MA status along with performance on the Wide Range Achievement Test Reading subtest , lifetime major depressive disorder , and lifetime average daily cannabis as covariates into each model. Age, education, race/ethnicity, and sex were not considered as model covariates because they were already included in the neurocognitive test T score demographic adjustments. Next, we added lifetime average daily alcohol use and days since last alcohol use to test whether historical alcohol use,grow table controlling for recency of alcohol use, incrementally predicted global functioning independent of MA status. Finally, an interaction term between MA status and lifetime average daily alcohol use was added to examine whether lifetime alcohol use modulated MA group differences in neurocognition.

To probe interaction effects, simple slope analyses were conducted by examining the association of global functioning with lifetime average daily alcohol use within each MA group, adjusting for covariates. To avoid multicollinearity with lifetime MDD, BDI-II was not included as a covariate in initial models. Instead, BDI-II was added as a post-hoc covariate to final models in order to rule out the potential confounding influence of active depressive symptoms. To enhance interpretability of the logistic regression results predicting likelihood of global neurocognitive impairment, we present odds ratios estimated with 95% confidence intervals . All analyses were performed using JMP Pro version 12.0.1 .The present study explored how lifetime patterns of alcohol consumption, specifically a metric averaging drinks per drinking day over the lifetime, related to neuropsychological performance among MA-dependent and MA-nonusing individuals. Based on the current literature detailing the independent, adverse neurobehavioral contributions of chronic MA and alcohol consumption, it was hypothesized that the MAþ group would exhibit worse neurocognitive performance and that greater alcohol use would exacerbate the deleterious neurocognitive effects of MA use. Consistent with prior studies, we demonstrate that MAþ individuals perform worse on average across all neurocognitive domains while exhibiting modestly higher rates of neurocognitive impairment and consuming more alcohol and cannabis than their MA– counterparts. Whereas heavier drinking increased the likelihood of global neurocognitive impairment in the absence of MA dependence, no additive effects of alcohol were observed among MAþ participants. Contrary to expectations, lifetime average daily alcohol use did not predict global T scores and in fact was associated with reduced risk of global neurocognitive impairment in the MAþ group. To our knowledge, this is the first study to explore potentially modulating effects of historical patterns of alcohol consumption, as opposed to recent heavy drinking, on MA-associated neurocognitive performance. Given the known neurotoxic and neurobehavioral consequences of heavy alcohol use , these results must be interpreted with caution. However, our finding that elevated historical levels of alcohol consumption attenuate MA-related global neurocognitive impairment is consistent with prior studies demonstrating that singly addicted stimulant abusers consistently experience greater levels of neurocognitive dysfunction than those who simultaneously abuse stimulants and alcohol .

These prior findings are particularly applicable to the current investigation as both studies classified participants based on lifetime patterns of chronic stimulant and alcohol use and administered comprehensive and validated neuropsychological batteries. Although studies of the neurocognitive effects of acute, combined stimulant and alcohol use may be less generalizable to our results, some studies have reported that administration of dextroamphetamine or amphetamine sulfate following ethanol-induced intoxication in humans may dampen ethanol-related neuropsychological decrements in psychomotor performance, executive function, and working memory . Nevertheless, further research is required to determine whether acute alcohol administration following MA-induced intoxication exhibits similar neurocognitive effects and to what extent such findings can be extrapolated to chronic substance abusers. Our unanticipated results with respect to MAþ participants necessitate that we critically examine potential statistical and behavioral confounds. The significant relationship between lifetime average daily alcohol use and the dichotomous global impairment variable, as opposed to the null effect of lifetime alcohol use on continuous global T scores, reflects fundamental differences between these two measures of global neurocognition. Global T scores are computed by averaging individual T scores across the entire battery and can represent performance across the entire neurocognitive spectrum . As a result, above average performance on some measures can mask impaired performance elsewhere. Conversely, the GDS-based impairment classification accounts for the frequency and severity of deficits across the test battery with less consideration given to performance in the normal range . Figure 1 demonstrates that although average global T scores in MAþ individuals remain stable as lifetime average daily alcohol use increases, resulting in a null association, there is greater variability in performance at low levels of alcohol use, resulting in a higher percentage of MAþ individuals being classified as impaired on the GDS at low levels of use. Similarly, the MAþ group had an average global T score that only fell .35 standard deviations below the mean , yet was twice as likely to have global impairment as compared to MA– individuals, suggesting that a global index of impairment may enhance detection of the subset of MA users that are disproportionally vulnerable to MA related brain insults. Conversely, MA group comparisons on domain-specific performance illustrate the utility of T scores in detecting subtle yet significant differences that do not necessarily translate to differences in rates of impairment.

The hypothesis that neurocognitive performance attributable to MA-induced neural injury may hinder the ability to detect the relatively subtle influence of alcohol is supported by evidence that MA abuse poses greater risk for neurocognitive deficits than alcohol abuse . Although our data demonstrate an adverse, multi-domain effect of MA dependence, this effect is modest and therefore unlikely to preclude us from detecting any additional influence of alcohol use patterns. From a poly substance use perspective, the strong positive correlation between self-reported lifetime MA and alcohol use indicates that the observed relationship between greater alcohol use and lower likelihood of global neurocognitive impairment is not an artifact of heavy drinkers having less exposure to MA. Although cannabis use correlated with alcohol use, and prior evidence suggests cannabis use may attenuate MA-related neurocognitive deficits , lifetime cannabis exposure did not suppress our significant findings nor did it account for variance in neurocognitive performance. Furthermore, the negligible effects of days since last alcohol use and depressive symptoms rule out MA group differences in recent alcohol consumption and psychiatric comorbidities as a source of variance in neurocognitive performance. In a meta-analysis examining the neurocognitive effects of duration of alcohol abstinence, Stavro and colleagues found that neurocognitive dysfunction decreased following sustained abstinence for at least a year. Importantly, this meta-analysis only included patients who met criteria for alcohol use disorder and excluded patients with non-alcohol substance use disorders. Given that the present study sample included MA dependent individuals with varying levels of alcohol consumption, neurocognitive recovery facilitated by increased duration of abstinence from alcohol may be more prominent for heavier drinking populations without comorbid substance use disorders. Moreover, our study criteria excluded DSMIV-based alcohol dependence within the past year as well as evidence of long-term lifetime alcoholism. Therefore, those meeting dependence criteria would have done so only in the past and on an episodic basis. With regard to MA group differences in time since last alcohol use, these are largely explained by many MAþ participants being in recovery and abstaining from all substances currently, vertical rack whereas MA– participants may include current social drinkers. Nevertheless, days since last alcohol use did not predict our outcomes. Drawing inferences about specific biological mechanisms underlying poly substance use in humans is particularly challenging given that substance use disorders, such as MA dependence, cannot be experimentally modeled as independent factors in randomized controlled trials, and observational studies are often under powered to examine potential confounds. Although the nature of our data prevents us from empirically investigating specific biological mechanisms that may explain the interactive effects of MA status and lifetime average daily alcohol use on neurocognitive functioning, we offer several plausible neurobiological interpretations. First, the cerebrovascular abnormalities evidenced in MA use are partially attributable to the vaso constrictive properties ofMA that result in platelet aggregation . Alcohol, in contrast, is recognized to have vasodilating properties that reduce platelet aggregation . Thus, alcohol-driven attenuation of MA-induced vasoconstriction may reduce the magnitude of neurovascular dysfunction and subsequent neurobehavioral deficits experienced by MA users.

It is important to note, however, that certain studies have demonstrated a biphasic vasoregulatory effect in which alcohol’s vasodilating properties may be limited to light-to-moderate drinkers, whereas heavier drinkers are at risk for a rebound effect in which an increase in platelet aggregation is observed following acute withdrawal from alcohol . An additional source of MA-associated neurotoxicity is the induction of brain hyperthermia through increased neural activation . Brain thermotoxicity is mediated through multi-level mechanisms in which adverse cellular , local , and systemic events can contribute to neurocognitive difficulties . Despite the sensations of warmth experienced during alcohol consumption, alcohol’s vasodilatory properties result in brain and body heat dissipation that may counteract the hyperthermic consequences of MA use. Animal experiments have demonstrated that rats exposed to alcohol before and after TBI recover from TBI-induced brain hyperthermia faster and exhibit fewer deficits in spatial learning than alcohol-naïve rats . Whether such thermoregulatory benefits of alcohol, and subsequent attenuation of neurocognitive impairments, hold in the context of MA-induced hyperthermia requires further investigation. Although the neurophysiological alterations associated with increased alcohol consumption may provide neuroprotective benefits in the context of MA addiction, our data demonstrate an adverse effect of lifetime average daily alcohol use on neurocognitive function in the absence of MA dependence. Unlike the MAþ group, who on average reported heavy lifetime alcohol consumption , MA− individuals on average reported low-risk alcohol intake , 2005. Neurocognitive performance in nondrinkers, low, and moderate drinkers has been widely studied yet has yielded mixed results. Whereas many researchers posit a “j-shaped” relationship, in which light-to-moderate consumption confers neurocognitive benefits over non drinking but heavy consumption is more neurotoxic than abstinence , other studies have either found no relationship or a negative association between low-to moderate consumption and neurobehavioral outcomes . Our findings are most consistent with the latter group of studies suggesting a deleterious dose-dependent effect of alcohol consumption, even at moderate levels, on cognition and brain structure . It is important to note that despite reaching statistical significance, our findings represent a small effect size in which one extra drink per day equates to about a one-half unit decrease in global T scores. As a result, the clinical significance of this relationship may be far more relevant for heavier drinkers with borderline neurocognitive performance than higher performing drinkers. Although the present study focuses on the conditional role of alcohol in MA-related neurocognitive performance, further studies that probe the neurocognitive effect of alcohol at varying levels of consumption and model non-linear relationships are warranted regardless of MA status. Understanding limitations of the current study may guide future research to clarify the observed differential effects of alcohol use on neurocognitive functioning among MAþ and MA− individuals. Unsurprisingly, the MAþ group displayed significantly greater lifetime average daily alcohol use than the MA− group. Although the distribution of residuals from regression models were carefully examined to ensure no assumptions of normality were violated, the group difference in lifetime average daily alcohol use may impact the reliability of our MA effect estimates at high levels of consumption in which the MA– group is underrepresented. Additionally, these estimates of lifetime alcohol consumption are fully dependent on participant self-report.

Several studies have found altered prefrontal cortex processing and executive dysfunction in marijuana users

Gonzalez et al. found no differences on the BART in a sample of young adult marijuana users versus non-using controls; however, Gonzales et al. allowed for recent marijuana use , with a median of three days since past use. Because previous studies of young marijuana users allowed for recent use, the effects of residual marijuana levels may have affected task performance. In the current study, we examined risk-taking via the BART in late adolescent marijuana users with at least two weeks of abstinence from marijuana, in comparison to non-using controls. This approach considers how marijuana users function relative to their non-using peers and reduces possible residual effects from recent substance use. We hypothesized that participants reporting greater substance use would demonstrate riskier BART performance. Further, previous studies have not yet examined the relationship of risk-taking to executive functioning in adolescent marijuana users. Executive function is a complex collection of abilities primarily modulated by the prefrontal cortex.Completing the BART has also been linked to increased prefrontal cortex activation in healthy controls , and a recent meta-analysis of neuro imaging studies suggested that individuals with substance use disorders may have altered risk processing compared to healthy controls, primarily in ventromedial prefrontal cortex, orbitofrontal cortex, striatum, and other areas involved in risk and decision-making . Given the involvement of the prefrontal cortex in both risk-taking and executive functioning, we examined whether elevated risk-taking, as measured by the BART, was associated with poorer executive functioning,cannabis grow facility layout as measured by traditional neuropsychological tests. We hypothesized that a riskier approach to the BART would be associated with poorer performance on executive function tests.Participants were part of a longitudinal study of marijuana’s effects on neurocognition during adolescence and young adulthood, with assessments at intake and at 18- and 36-month follow-ups . Adolescents were recruited from local high schools.

Teens and their parents/guardians were screened for demographics, psychosocial functioning, and family history of Diagnostic and Statistical Manual for Mental Disorders, 4th Ed. , 2000 substance use and other Axis I disorders. Confidentiality was ensured within legal limits to encourage full disclosure. Prior to participation, written informed assent and consent were obtained in accordance with the University of California, San Diego Human Research Protections Program. At study intake, exclusionary criteria included history of psychiatric disorder other than substance use disorder, serious medical problem or head trauma, premature birth, prenatal drug or alcohol exposure, and substance use during monitored abstinence. Intake classification criteria for the marijuana-user group included >60 lifetime marijuana experiences; past month marijuana use; <100 lifetime uses of drugs other than marijuana, alcohol, or nicotine; and not meeting Cahalan criteria for heavy drinking status . To produce an adequate sample size, controls were included if they had <5 lifetime experiences with marijuana , no previous use of any other drug except nicotine or alcohol, and did not meet criteria for heavy drinking status. The current data were collected at the 18-month follow-up, when participants were aged 17–20 years. A total of 48 marijuana users and 52 controls completed the BART task at the 18-month follow-up; however, 24 marijuana users and 18 controls were excluded from analyses based on the following abstinence requirements: at least two weeks since last use of marijuana, other drugs, or alcohol binge ; and at least three days since last use of any alcohol or psychiatric medications . Beyond the abstinence requirements, follow-up controls were further excluded for meeting abuse or dependence criteria for alcohol or any other substance . One participant in the baseline marijuana group had no marijuana uses in the previous 18 months and was also excluded, and one additional control was excluded due to meeting DSM-IV criteria for current post-traumatic stress disorder. Following these exclusions, the resulting sample of 58 demographically matched adolescents and young adults included 24 marijuana users and 34 non-using controls. At the 18-month follow-up, marijuana users were about seven months older , and as expected, reported higher levels of marijuana, alcohol, and other drug use than controls. marijuana users had 200+ lifetime marijuana use episodes and <130 lifetime experiences with other drugs.

In addition, 10 marijuana users met DSM-IV criteria for marijuana abuse and seven for marijuana dependence , 10 met criteria for alcohol abuse, and two met criteria for other drug abuse. At the 18-month follow-up, the 34 controls had ≤15 lifetime experiences with marijuana, minimal to no previous other drug use except nicotine or alcohol .Participants were administered the Customary Drinking and Drug Use Record to evaluate their lifetime, past three-month, and past 18-month use of nicotine, alcohol, marijuana, stimulants , hallucinogens, inhalants, opiates , dissociatives , sedatives , and abuse of over-the-counter or prescription medications. Teens were also assessed for alcohol and drug withdrawal symptoms, related life problems, and DSM-IV abuse and dependence criteria . The Timeline Follow back facilitated recall of substance use over the past 28 days through a calendar layout.The BART is a computer-based risk-taking assessment . Participants used the space bar to pump 30 simulated balloons one at a time to achieve the highest possible score. Balloons pop at an unpredictable rate , and a noise follows each response . The points earned for a balloon are lost if it pops, but temporary points can be saved by choosing “Save Points.” Participants weigh the increasing risk of popping each balloon against the potential gain of continuing to pump the balloon . The primary outcome measures were the mean number of pumps for balloons that did not pop and the total number of popped balloons during the session. High values on either variable suggest greater risk taking. The number of points earned on any balloon and the total points saved are not revealed to the participant – only whether they had earned a small, medium, big, or bonus prize depending on the amount of points saved. They were shown the possible candy rewards prior to starting the task and received the reward immediately upon completion of the task. Participants had no practice trials to assess risk, and each participant completed the same task . This measure has good test-retest reliability .Participants were abstinent from marijuana, other drugs, and alcohol binge for at least two weeks prior to the assessment, verified with biweekly breathalyzer tests and urine screens including at the neuropsychological testing session.

The urine screen tested for major substances including amphetamines, barbiturates, benzodiazepines, cocaine metabolites, marijuana metabolites, and opiates. Exclusions for recent substance use are described above in the section on participants. All participants completed questionnaires and the neuropsychological battery. Teens and their parents/guardians received monetary compensation upon study completion.We used Fisher’s Exact Tests to compare categorical variables between groups and analysis of variance to examine group differences on continuous variables. Some alcohol and drug use variables did not meet requirements for parametric analysis; therefore we used the Mann-Whitney procedure to compare these characteristics between groups. Because marijuana users were slightly older than controls, age was controlled in analyses of test performance using univariate analysis of covariance . Effect sizes are presented as partial eta-squared , and interpretations of statistical significance were made if p<0.05. We used Pearson correlations to examine associations between risk-taking, demographic, and neuropsychological variables. As an exploratory analysis, we performed hierarchical multiple regressions to examine whether BART performance predicted past 18-month substance use, as described below. Distributions of substance use variables were examined and appropriately log10 transformed to meet the assumptions of parametric analysis.This study examined risk taking via the BART in late adolescents with or without a history of marijuana use. As hypothesized, participants reporting greater substance use evidenced riskier BART performance. Specifically, marijuana users with at least two weeks of abstinence from marijuana, other drugs,indoor grow shelves or alcohol binge popped more balloons than non-using controls throughout the task, especially in the first 20 balloons. Although speculative, it appears that the marijuana users started the task with a higher level of risk taking. After receiving feedback about their performance , they attempted to modify their approach to avoid popping balloons. The controls may have taken a similar approach, as illustrated in Figure 1; however, the marijuana users remained slightly more “risky” in their approach throughout the test. Notably, the groups did not significantly differ in average adjusted pumps, which is the most commonly used variable for this task. Importantly, Pleskac et al. have suggested that the average adjusted pumps score may be biased and an underestimate of risky responses because it excludes the trials in which the balloon popped, as explained further below. For this reason, the number of popped balloons may be a more sensitive measure of risk-taking. Importantly, the groups were matched on self-reported levels of depressive, anxiety, and internalizing symptoms; marijuana users scored higher on externalizing behavior, as expected.

BART performance was not associated with these self-reported mood and personality characteristics or demographic variables including age. This suggests that group differences in risk taking may be due to marijuana or other substance use, rather than other personal characteristics. Previous studies have found mixed results. Consistent with the current study, some found that alcohol and other substance use was related to riskier BART performance ; however, others did not find group differences between non-using controls and at-risk/ addicted individuals or recently abstinent marijuana users using the BART average adjusted pumps variable . Further, BART performance did not relate to cannabis use disorder symptoms in Gonzalez et al., 2012. Our study is consistent with Meda et al. and Gonzalez et al. with regard to finding no group difference on average adjusted pumps; however, the previous studies did not examine group differences in the number of popped balloons. We also found that having a riskier BART performance significantly predicted a higher number of other drug use episodes in the past 18 months, above and beyond the effects of age. The equation using popped balloons to predict past 18-month marijuana use was also significant, but higher age was a stronger predictor than popped balloons. Having a riskier BART performance did not predict recent alcohol use. In other words, it appears that BART performance was associated with other drug use but not alcohol or marijuana use when also considering age. However, that result did not remain significant when controls were removed from the analysis. The BART may therefore have had relatively low sensitivity for measuring additional risk among regular marijuana users in this sample. Future studies could explore whether BART performance is a useful predictor of additional risk above and beyond alcohol and marijuana use. In addition to elevated BART risk-taking, abstinent marijuana users performed worse than controls on one aspect of executive functioning measured, consistent with previous studies reporting deficient executive skills or abnormal brain activation among marijuana users in this and other samples . Specifically, marijuana users exhibited poorer visuomotor set-shifting relative to non-using controls. This suggests that young, abstinent marijuana users may have a mild weakness in cognitive flexibility in the context of changing task demands. Nevertheless, it is not clear if the average group difference on this task is clinically meaningful, and marijuana users did not differ from controls on other aspects of executive skills including working memory, verbal fluency, and planning. Although not correlated with putative measures of executive function, riskier BART performance was associated with faster psychomotor sequencing speed. It is possible that a faster rate of responding may produce more popped balloons, or as speculation, risky behavior without adequate forethought may result in losses. This may concur with Solowij et al. who reported that marijuana using adolescents demonstrated “reflection impulsivity,” having faster response times even when uncertain and making more errors. Vigil-Colet also found that BART performance was most strongly related to “functional impulsivity,” a style in which decisions are made quickly and impulsively under certain beneficial circumstances. On the other hand, Meda et al. used principal components analysis to show that risk-taking may be distinct from other measures of the multidimensional construct of impulsivity . Therefore the relationship between a faster processing speed, impulsivity, and risk-taking is not entirely clear and warrants additional study. Overall, the BART appears to measure distinct aspects of risk-taking that have been associated with real-world behavior , suggesting it is a useful tool for assessing risk-taking in adolescents and young adults. Since the BART was not correlated with established tests of executive functioning, this suggests that it is measuring a behavior distinct from executive function, or at least distinct from the present tests of executive functions.

Regulations have set a maximum batch size of 50 pounds of cannabis flowers

To make these cost calculations we accounted for inventory that first fails testing, but then is remediated.In addition, to understand the opportunity cost of cannabis used in the tests or lost in the process, we use data from wholesale prices and a survey of retail cannabis prices conducted by the University of California Agricultural Issues Center.Based on this information, we developed a cost per unit of cannabis tested for representative labs of three different sizes to approximate the distribution of costs in the industry.For simplicity, we assumed that testing labs of different sizes use the same inputs, but in different proportions, to provide testing services.We assume economies of scale with higher share of capital costs per unit of output for the smaller labs.We used information reported by the Bureau of Cannabis Control in the first half of 2018 to compile a list of cannabis licensed testing laboratories and distributors in California.We used information on the geographic location of testing labs relative to cannabis production and consumption to assess the cost of transporting samples from distributors to testing labs.In March 2019, there were 49 active testing licensees and 1,213 licensed distributors.Both testing licensees and distributors are located in many areas across the state, but they are concentrated in traditional cannabis production areas in the North Coast region of California and in large population centers.Table 5 shows capacities, annualized capital costs,indoor growers and other annual expenses for three size categories of testing labs: small, medium and large.The size categories are based on the number of samples analyzed annually and were chosen to represent typical firms, based on our discussions with the industry.We assume about 25% of labs are small, 25% are large and the remaining half are in the medium category.By regulation, these labs test only cannabis.

The annualized cost of specific testing equipment and other general laboratory equipment is a significant share of total annual costs.The cost of equipment and installation is about $1.5 million fora small lab, about $2.4 million for a medium lab and about $3.8 for a large lab.These costs are expressed as annual flows in table 5.Our survey and discussions with laboratories provide the rest of the estimated costs.Equipment maintenance costs, rent, utilities and labor also are large cost categories.Each of these costs is less than proportional to the number of samples tested and thus contributes to economies of scale.This cost of consumable supplies is calculated on a per sample basis and thus is proportional to the number of samples tested.Finally, the return to risk and profit is estimated as 15% of the sum of the foregoing expenditures.Our estimated total annual costs are about $1.6 million for small labs, $3.3 million for medium labs and $7.0 million for large labs.The scale advantage of larger testing labs is reflected in the testing cost per sample: $324 for large labs, compared with $562 for medium labs and $750 for small labs.These cost differences arise from economies in scale in the use of laboratory space, equipment and labor.Each large testing lab processes about 10 times the number of samples as a small lab but has annualized operating costs only about five times those of a typical small testing lab.That means that small-scale labs tend to specialize in servicing more remote cultivators or manufacturers that have products handled by smaller and more remote distributors located at a cost-prohibitive distance from large labs.We used data on the annual testing capacities of small, medium and large labs and our assumption about the number labs of each size to calculate the share of testing done by labs of each size category.We expect that small labs will test about 6% of all legal cannabis in the state by volume, medium-sized labs will test about 33% of legal cannabis, and large labs will test 61% of legal cannabis.Using these shares, the weighted average cost per sample tested is about $428.Let us now turn from the cost per batch tested to the cost per pound of cannabis marketed.

The per pound costs of laboratory testing depends on the number of pounds tested in each test.Therefore, we must consider batch size.We expect that the batch size will differ within this constraint depending on the product type and origin and size of the cultivator and manufacturer and explore implications of batch size differences.Using the weighted average cost per sample of $428, the testing cost for a small batch of 5 pounds is $85.60, while for the largest-allowed batch size of 50 pounds, the cost is just $8.56 per pound.Next, we turn to several costs not included in the cost of testing a sample in the lab.First and most straight forward is the cost of compliance with security measured including video surveillance and archival, disposal and quarantine, and other compliance costs that we estimated were equivalent to $4.88 per pound for small labs, $4.06 per pound for large labs and $3.25 per pound for large labs for a weighted average of $3.62 per pound.The cost of testing requirements on a retail cost basis is best expressed as the full cost per unit of cannabis that reaches the market.Expressing the full cost in this way raises two additional costs.The first is simple: the value of the cannabis used up in the testing procedure.Based on MAUCRSA, the sample size must be at least 0.35% of the total batch of cannabis tested.We use an average wholesale value of $1,360 per pound of cannabis flower equivalent at the testing stage, which represents a recent weighted average price across outdoor grown, greenhouse grown and indoor grown cannabis and products.Thus, for each pound of cannabis tested, flower worth $4.76 is used up.The second issue, costs associated with a failure to pass the test, is more complex.These costs include the cost of the testing process as well as the cost of the cannabis that must be destroyed when it is considered unacceptable to be marketed by virtue of a failed test.Stringent maximums for pesticides, microbials and other contamination mean that there will be a significant chance that a sample is rejected.In some cases, the owner will attempt to remediate or process that batch, intending to eliminate the cause of the non-passing the test.A batch can be remediated up to two times.If a batch fails its testing after its second remediation, regulations mandate that that batch must be destroyed in a verifiable way.This is a major cost of the testing regime required by California legislation and regulation.To estimate the cost of such rejections, we used a range of potential rejection rates, drawing from information that was available on contamination of cannabis in other states.However, the experience of other states is of limited value and must be adjusted based on information from industry sources.Washington state mandates tests on potency, moisture, foreign matter, microbiological and mycotoxin screening, residual solvent and heavy metals, but, unlike in California, testing on pesticide residues is not mandatory.Washington state enforcement is based on spot checks.Based on Washington state data, we found that in 2017, the second year after the testing began, 8% of the total samples submitted failed one or more tests.

Colorado state mandates tests on residual solvents, microbial, mycotoxins, heavy metals, pesticides and potency.The Colorado Marijuana Enforcement Division reported that during the first six months of 2018, 8.9% of total samples of adult-use cannabis failed testing.Testing on pesticide residues only became mandatory in August of 2018 in Colorado, so systematic data on test results were not available.However, the Department of Agriculture in Colorado informed us that 60% of spot-checks based on complaints or concerns between 2015 and 2017 found pesticide residues.Given the cost of cannabis that must be destroyed in case of failed tests, cultivators and manufacturers may pre-test to decrease the chances of failing official tests.For our cost analysis, we assume that 25% of cannabis is pre-tested before being submitted for the formal and binding tests.To express costs in terms of the pounds of cannabis legally marketed, and account for pretesting and pounds lost because of testing, we need to express the ratio of pounds tested to pounds that pass testing.The costs of establishing and operating a cannabis testing facility that meets California’s mandates are largely accounted for by investment in precise equipment, the cost of highly skilled labor and costs of materials.Testing is expensive, but the lost value of cannabis that fails tests to enter the legal retail market is an even bigger issue.It is difficult to predict rejection rates with great confidence; the data we present, however,vertical hydroponic system is consistent with reports of pesticide detection in California food crops and information available from other states.Evidence suggests that major drivers of both direct laboratory costs and lost cannabis costs are low or zero tolerance levels set for pesticides and the difficulty of dealing with microbial contamination.We have shown that if these low tolerance levels were applied to other California food crops, a significant proportion would have failed tests in recent years.Thus California’s safety standards for cannabis are tight compared to other states’ standards and to standards for other products within California.We note that there may be safety reasons that cannabis is subject to such tight tolerance levels, but they are not in the literature and are beyond the scope of this article.California’s system for testing cannabis has been under pressure since the implementation of the state’s testing regime in July 2018 because of difficulties in supplying the market with product that has passed the tests and has been labeled correctly.Some producers, after receiving inconsistent test results for contaminant residues from different laboratories, have voluntarily recalled product.However, California has not yet reported detailed data on official test rejection rates.Costs of testing will be reflected in the price of marketed legal cannabis.Thus it is crucial to understand the value that testing creates for consumers compared to the costs.Competition between legal cannabis and untested illegal cannabis is a major issue in cannabis policy.Rules that help ensure safe and high-quality products for consumers of legal cannabis can encourage some consumers to shift from the illegal supply chain to the legal, licensed supply chain.Before the passage of AUMA in 2016, the low prevalence of testing in California’s essentially unregulated market for medicinal cannabis indicated that many consumers entertained a limited willingness to pay for higher safety standards.

This suggests that at least some consumers may remain today in the illegal, low-priced market, even though certified, tested products are available in the licensed supply chain.Taxes and regulations will make legal cannabis more expensive than illegal cannabis.However, safety testing is the basis of product differentiation for legal cannabis sold through licensed retailers.In some agricultural product industries, growers have urged product safety and consistency standards, as well as more stringent testing standards, to increase demand.As the regulated cannabis market develops, we expect that increased access to data will help clarify the impact on demand of mandatory testing rules.PM2.5 concentrations were measured continuously, using two, co-located laser photometers , placed 80-100 cm above the floor, for five weeks in 2019.Room occupancy was not monitored.In week 1, instruments were located 30-122 cm from the sources.During week 2 and weeks 3-5, they were 6-9 and 2- 4 meters from the nearest sources, respectively.Photometers were operated with impactors to exclude particles over 2.5 µm in diameter.The photometers were zeroed once a day and calibrated gravimetrically using a controlled cigarette smoke generation system before and after each experiment.Gravimetric data from 20 cigarette smoke experiments, when plotted against the matching photometric data and forced through zero, yielded a calibration factor of 0.31 , which was was applied to the dispensary photometric data.Cannabis PM2.5 samples were also collected in the dispensary on filters for one week , and a preliminary photometer calibration factor was calculated as above.PM2.5 concentrations in outdoor air were estimated using data from an US EPA monitoring station located 2.5 km from the dispensary in an area with similar ambient pollution sources.The retail and consumption space was a single room of approximately 400 m3.Cannabis consumption occurred at three tables in one corner of the room, with sales counters located in the opposite corner.The room was served by building HVAC and by four window air conditioners that did not admit fresh air.The air conditioners had dust filters and we were unable to examine filtration in the building HVAC system.

Colorado instituted safe storage guidelines to mitigate adverse effects in children from acute cannabis intoxication

The soil that remained adhered to the roots after removal from the ground was used to produce the rhizosphere soil samples.The rhizosphere soil was removed from the roots by shaking the root into a whirlpak bag.All samples were immediately transferred to storage at 4uC for shipping back to the laboratory for processing.All root samples were rinsed with alcohol and sterile water before the extraction.DNA was isolated from 0.25 g of soil or root per extraction using standard protocol for PowerSoil DNA Isolation Kit , with the modification of heating the extraction at 65uC for 10 minutes prior to the initial vortex step.The soil physicochemical data was generated by Fruit Growers Laboratory , including total carbon and nitrogen concentrations, pH, salinity, and water content for all samples.Endorhiza, rhizosphere, and bulk soil samples for the second experiment were taken from 6 organically-grown Cannabis plants of two different strains from two locations in August, 2012: Vista and Orange County, California.Triplicate samples were taken from each of the six plants and surrounding rhizosphere , as well as from each of the two bulk soils used in the different locations , totaling 42 samples.In contrast to the first experiment, all samples were taken two weeks prior to harvest.Additionally, triplicate samples from the second experiment were taken from different roots on the same plant.Cannabinoid data was taken from the buds of three White Widow plants and one Mauie Wowie plant.All cannabinoid data was processed at Delta-9-Technologies, LLC.Otherwise, sampling procedure matched the first experiment.Recent literature has suggested a two-step selection model for the endorhiza, where bulk-soil microbial communities are filtered by increased concentration of rhizodeposits, followed by convergent host genotype-dependent selection on endophytic communities.Results from both experiments support many of the expectations produced by this model.Most importantly,dry rack cannabis the principal coordinate analysis plots for the second experiment demonstrate highly significant clustering patterns.

First, soil type is the main determinant of PC1 for the unweighted analysis of the second experiment, revealing that soil is undoubtedly the most important factor in all samples for determining what microbes are present.Second, communities within both soil types demonstrate a similar community shift from bulk soil to endorhiza samples along PC2 , which is dominated by differentiation between sample types.Specifically, endorhiza samples have high, positive values along PC2, rhizosphere samples have intermediate values, and bulk soil samples have more negative values.Third, Cannabis strain is the main determinant of PC1 for the weighted analysis of all samples in the second experiment, suggesting that convergent host genotype-dependent selection acts through controlling community structure more than composition.PCoA results exhibit how all sample types form significantly differentiated clusters in weighted analyses but that only rhizosphere and endorhiza samples form significantly differentiated clusters in unweighted analyses, suggesting niche-filtering of microbes in rhizosphere and endorhiza samples from bulk soil.Furthermore, there were no significant segregating OTUs based on unweighted analysis between cultivars in endorhiza and rhizosphere samples in the second experiment, however there were 71 when abundance was accounted for.This differs greatly from the 657 OTUs that significantly differ between soil types in the same dataset.Testing of the two-step selection model with pairwise comparisons of shared OTUs between endorhiza and bulk soil samples also validated the hypothesis that a portion of the endophytic microbes are inherited and selected from the surrounding soil, showing significantly more OTU overlap between endorhiza and their own bulk soil compared to endorhiza and foreign bulk soil.Given the results from the second experiment strongly suggesting that Cannabis cultivars have important structuring effects on both rhizosphere and endorhiza samples, it may seem troubling that results from the first experiment do not suggest this for the rhizosphere samples.However, differences in Cellvibrio abundance between experiments show that root decay could have diminished the rhizosphere effect, thus diminishing this potential signal.Sampling for the first experiment was done post-harvest, when plant tissues were undergoing senescence and decay, while samples for the second experiment were taken from actively growing plants.Considering the extensive work demonstrating the importance of plant growth stage on the microbiota, as well as the plant-soil feed backs identified in structuring below ground microbial communities, the differences between the first and second experiments are unsurprising.

The similarities, however, are surprising.In particular, that cultivar-specificity could be identified in the microbiota within the endorhiza samples in the first experiment without any input of cultivar-specific metabolites from the living plant for weeks.Although we have presented several highly significant findings supporting expectations of the two-step selection model, some expectations remain to be validated.Specifically, although the mean beta-diversity distances indicate that rhizosphere and endorhiza samples are closer than bulk soil and endorhiza samples, this difference was not significant and thus provides little evidence for the first differentiation step of the two-step selection model.Future work with the Cannabis micro-biome should focus on elucidating the role of cultivar on rhizosphere, as well as what aspects of host genotype are producing the structure observed across Cannabis strains.Increased testing of cannabinoids and decoupling this variation from edaphic factors will improve our understanding of the importance of cannabinoid production in structuring endorhiza communities.Sampling a time series of endorhiza communities across several plants may help us to understand natural variation in the endorhiza during the reproductive cycles of Cannabis.Understanding this natural variation will help direct future mechanistic studies aimed at using microbial communities to increase plant fitness, suppress disease, or augment desired metabolite production.Legalization of cannabis use is increasingly widespread across the United States, but the ramifications are unknown.In 2016 California approved Proposition 64 legalizing recreational cannabis.Unintentional pediatric ingestion is one possible ramification, as occurred in Colorado after legalization in 2009.Regional poison center cases involving marijuana increased by an average 34% per year from 2009 to 2015 in Colorado.During that time, 34% of cases involved self-reported cases of poor product storage.Children who unintentionally ingest cannabis can present with lethargy, ataxia, tachycardia, mydriasis, and hypotonia, which can lead to preventable emergency department visits, invasive workups, and hospital admissions.Despite the institution of safe storage guidelines in Colorado, a recent study found continuing sub-optimal storage practices in that state.5 This trend was mirrored in the use of medical marijuana, as oncology patients and their caregivers reported sub-optimal storage practices and had received little storage education from healthcare providers.

The 2016 California legislation did not include regulations on the safe storage and disposal of cannabis products, creating a potential for similarly unsafe storage practices.The purpose of this study, which was based on a community presenting to a pediatric ED, was to assess the prevalence of cannabis and how it is stored in the home and, secondly, to assess attitudes regarding use of cannabis and storage education among Californians who live in households with children.We conducted a cross-sectional survey with a goal enrollment of 400 adult visitors in an academic pediatric ED in California from June 8–August 16, 2018.During this time, a convenience sample between the hours of 8 am -10 pm was conducted daily in which all adult visitors were screened for eligibility and subsequently approached.The survey was generated and finalized by the investigators and research assistants based on similar studies found during literature review.The survey contained 42 yes-no or Likert-scale questions regarding cannabis use and storage, and education on cannabis storage.Eligible participants were >18 years old and lived in a household with children <18 years old.Participants were excluded if they did not speak English or Spanish, or if the patient was critically ill.Only one survey was administered per household.All participants were notified that their responses were not shared with law enforcement or their care team, and they completed the survey in the absence of a RA.English-speaking participants filled out the survey electronically and submitted their responses directly into Research Electronic Data Capture.Spanish-speaking participants filled out a Spanish-language survey on paper, which was subsequently placed in a lockbox after which these de-identified surveys were uploaded to REDCap weekly.We used descriptive statistics to analyze data.Subjects who were screened but excluded were not tracked during this study.The UC Davis Institutional Review Board approved this study.A 2017 national survey indicated that as many as 11.5% of California adults reported regular cannabis use.Of adults surveyed, 14.5% reported cannabis use in a home with children.Since the legalization of cannabis in California, there has been a steady rise in prevalence of use,7 likely due to increased availability.In our sample, users perceived cannabis to be significantly safer for both adult use and possession inside a home with children, as compared with non-users.Further study is warranted to investigate how the public perceives the risk of cannabis as more time passes since legalization.Currently, little research exists on cannabis storage in homes with children,roll bench and there is no research that describes sources of storage information.Both users and non-users strongly felt that safe storage was important despite poor compliance with safe storage practices.Our results suggest a lack of educational sources regarding safe storage despite 23 years of medical cannabis use in California.The Public Health Department of Colorado set guidelines including locking, hiding, and using child-resistant packaging, yet California does not currently define safe storage.Providing guidelines at a local or state level may provide a reference for cannabis users as well as healthcare providers.

Based on participant responses, cannabis dispensaries may also serve as another point for the distribution of safe storage information.With the increasing prevalence of cannabis use in California,downstream effects on the pediatric population should be further investigated.Healthcare providers in primary care, pediatrics, and the ED should be prepared to screen and educate families on cannabis use and the importance of safe storage in homes with children.Nonpharmaceutical interventions were developed in response to the 2009 H1N1 pandemic and included a protocol to slow the spread of future novel respiratory influenza A virus pandemics.NPIs are strategies for disease control when no pharmaceutical alternative exists and include actions at the personal, environmental, and community level.Specifically, NPIs put in place during the pandemic included travel restriction, restriction of mass gatherings and recommendations for transition to virtual events, social distancing measures and stay-athome orders, closure of non-essential work spaces and schools, and cloth face covering guidance.3,8 However, it is unclear what effect, both intended and unintended, these policy implications have on populations.It is also unclear what effect the pandemic itself has had and will have on populations.A study from the Centers for Disease Control and Prevention examined differences among stay-at-home orders across US states from March 1st to May 31st, 2020, on population movement.Stay-at-home orders were associated with decreased population movement; however, movement increased significantly as states began lifting restrictions.Kaufman et al.reported the initial effect of state variation in social distancing policies and non-essential business closures on COVID-19 rates.Social distancing and closure of non-essential businesses and public schools were shown to reduce daily COVID-19 cases by 15.4% with effects varying across states.10 Finally, Pan et al.showed that there was heterogeneity in NPI domains across the US census region and concluded that states with the most aggressive policies had the highest mitigation of COVID-19 infection.11 While heterogeneity in intensity and duration of state policies on COVID-19 mitigation were demonstrated, all such studies have been restricted to the initial wave of the pandemic and have only assessed the associations of policies on COVID-19 infection spread at the population level.The COVID-19 pandemic and policy interventions such as social distancing, closure of spaces for gathering, and stay-at-home orders may have had varying economic, health, and social effects across different populations.Of particular concern, are negative implications on lesbian, gay, bisexual, transgender, and queer and other sexual minority populations, an already vulnerable, marginalized, and stigmatized group with even larger disparities among racially marginalized communites.The COVID-19 pandemic has highlighted and exacerbated challenges for the LGBTQ community which include rising food and shelter insecurity, economic fallout, job loss, disruption in health care, elevated risk of domestic and family violence, social isolation, increased anxiety, scapegoating/discrimination/stigma, abuse of state power, and concerns about organizational survival.There is an estimated 16 million LGBTQ adults and youth in the United States of which, 5 million work in jobs that are more likely impacted due to the COVID- 19 pandemic.For instance, 15% work in restaurants, 7.5% in hospitals, 7% in K-12 education, 7% in colleges/universities, and 4% in retail, all industries that have been impacted by the pandemic.Moreover, LGBTQ communities before and during the pandemic were more likely to be unemployed, at increased risk of poverty, have issues affording health care, and experience greater workplace discrimination compared to cisgender and straight people.

Future studies should recruit a larger sample size as it will allow for greater generalizability and further analyses

Responses by managers was a common theme discussed by workers as managers have the direct ability to ban customers based on inappropriate behavior and were often the first point-of-contact for workers to report an experience of harassment.The risk of continued harassment is exasperated by apathetic management teams who were described as prioritizing customer satisfaction over workers’ safety.Workers also illustrated the unique history of cannabis as a heavily sexualized industry whose legacy continues to permeate the industry today and negatively impact worker’s experience with sexual harassment.According to interviews, workers believed that customers either could not or refused to distinguish legally operating dispensaries from trap shops where women were explicitly used as props to sell product.The lack of distinction encourages the entitlement customers feel towards exploiting cannabis workers without repercussions.Interview results presented a paradox within the cannabis industry in which legalization introduced new protections to workers while simultaneously ushering in the corporate model of the “customer is always right,” which previous studies highlight as a detriment to the ability of workers to protect themselves from threatening customers.Furthermore, regarding research question five, data indicated workers were most interested in sexual harassment-based training for all workers, managers and supervisors as well establishing and publicizing clear policies on harassment.As previously mentioned, insufficient handling of sexual harassment cases by mangers was a common theme among all interviewees, highlighting the need for their additional training.Through interviews,drying cannabis workers were able to explain, in more detail, what they would like to see covered in a sexual harassment training.Likewise, interviews provided the opportunity for workers to explain exactly what policies or guidelines they would like established and publicized in their workplace.

Examples of policies included being able to ask a security guard to walk you home, an anonymous hotline number and permission to ask security guards for assistance in closing a store for the night.Given the unique study population of this project, there are several limitations to consider when interpreting the results.As previously mentioned, the sample of survey respondents was a convenience sample of cannabis employees represented by UFCW Local 770; respondents were not randomly sampled from all cannabis retail employees in Los Angeles County.Likewise, interview participants were also recruited through snowball sampling and were not randomly selected.All workers in the study sample are represented by a labor union and therefore the generalizability of the findings to all workers in the cannabis industry is limited as rank-and-file cannabis members of UFCW represent only a small subset of the cannabis industry.And as labor unions continue to grow their membership among cannabis workers, additional studies should compare the experiences with sexual harassment among unionized and non-unionized workers.The small sample size reduced the power of the study and created challenges for isolating effect sizes between the outcomes of interest and the independent variables, particularly in the multivariate models.With the understanding that sexual harassment is an under reported phenomenon, the analyses were likely impacted by respondents who reported never experiencing sexual harassment as it is possible workers simply did not feel comfortable disclosing such information.A larger sample size of workers across the state or ideally the nation as more states legalize the consumption and commerce of cannabis may also reveal regional differences in the effects of laws and policies that protect workers’ safety.There were also several issues regarding the survey tool.Although the survey was able to gauge frequency of harassment experienced by respondents using a Likert scale, it was not conducive to creating a discrete variable of harassment and consequently incidence rate could not be calculated.For example, the response option “once a month or less” could imply harassment was experienced anywhere from two to 12 times in the last 12 months as it was the second option after reporting experiencing harassment “once” in the past 12 months.

Providing more definitive response options may aid in developing more epidemiologically accurate variables.Questions from the SEQ-DoD were also originally developed to measure sexual harassment as it is experienced by women and studies show it is not as effective for capturing the experiences of men.In order to capture more precisely the phenomena of sexual harassment by all participants, future studies should utilize a more comprehensive survey for sexual harassment.Recall bias was also present in data collection as respondents were asked to remember specific examples of sexual harassment and the frequency at which those experiences occurred in the last 12 months.Finally, without a direct comparison to another workplace or industry applying the same methodology, it is difficult to make definitive statements about prevalence of sexual harassment in cannabis relative to other industries.In 2016, when voters approved Proposition 64, they set the stage for radical change across California’s cannabis landscape.Licensed, regulated cannabis stores would soon throw open their doors.The state’s vast cannabis industry would begin to emerge from illegality, though unlicensed operations would surely persist.UC researchers immediately understood that cannabis legalization would present California with pressing new questions, along numerous dimensions, that could only be answered through rigorous, broad ranging research.How would legalized cannabis cultivation affect the state’s water, wildlife and forests? How might impaired driving, or interconnections between cannabis and tobacco, influence public health? How would tax and regulatory policy affect the rate at which cannabis cultivators abandoned the illegal market? These questions and many more are now the subject of research around the UC system, and multiple campuses are establishing centers dedicated to cannabis research.This article surveys UC’s emerging architecture for cannabis research in the legalization era — and presents a sampling of notable research projects, both completed and ongoing.

The Cannabis Research Center at UC Berkeley is an interdisciplinary program that, bringing together social, physical and natural scientists, evaluates the environmental impacts of cannabis cultivation; investigates the policy-related and regulatory dimensions of cultivation; and directly engages cannabis farmers and cannabis-growing communities.The center, according to Ted Grantham — one of three CRC co-directors and a UC Cooperative Extension assistant specialist affiliated with UC Berkeley’s Department of Environmental Science, Policy, and Management — is “focused on cannabis as an agricultural crop, grown in particular places by particular communities with unique characteristics.” For Grantham and the center’s co-founders, establishing the program was “a chance to develop policy-relevant research at the time of legalization and a time of rapidly shifting cultivation practices.” The center’s co-directors, in addition to Grantham, are Van Butsic — a UCCE assistant specialist affiliated with UC Berkeley’s Department of Environmental Science, Policy, and Management — and Eric Biber, a UC Berkeley professor of law.Other CRC researchers are associated with entities such as the UC Berkeley Department of Integrative Biology, the UC Berkeley Geography Department, the UC Merced Environmental Engineering program and The Nature Conservancy.The center itself is affiliated with the UC Berkeley Social Science Matrix.The CRC formally launched with a public event in January.The center’s ongoing research includes a multifaceted project to assess specific aspects of Northern California’s cannabis farms, including the number and size of non-compliant cultivation sites; the environmental effects of non-compliant sites ; and the challenges to regulatory compliance that cannabis cultivators encounter.According to a grant proposal associated with the research, the project is motivated by an urgent need to understand the environmental threats posed by non-compliant farms and the reasons that some farms successfully navigate state regulations while others fail.The researchers are combining high-resolution satellite images with local and state permitting data to identify permitted and non-permitted cultivation sites.In parallel, the researchers are combining permit specifications with water use models to estimate the effects on stream flows of non-permitted versus permitted cultivation.Additionally, they are determining which factors associated with cannabis cultivation are most closely linked to compliance — whether parcels are large or small, old or new — and, through written grower surveys and in-person interviews, they are seeking to understand what stands in the way of cultivator compliance.Ultimately, the work will yield a policy report outlining ways in which state and local governments can decrease the harm of non-compliant cannabis cultivation while increasing rates of compliance.The research is supported by a grant from the Campbell Foundation, provided through the Resource Legacy Fund.In another example of CRC research focused on cannabis and the environment, last year Butsic, Jennifer Carah and additional co-authors published the results of their work on “agricultural frontiers”.These are places where,ebb flow due to increased profit potential for agricultural activity, land is newly cultivated — frequently resulting in environmental impacts such as forest fragmentation and threats to sensitive species.Such transformations, the authors write, occur when economic circumstances are altered by some new mechanism — such as, in the case of cannabis, a new legal status.The researchers, documenting the emergence of such a frontier, studied cannabis cultivation sites in Humboldt and Mendocino counties from 2012 to 2016.

Using satellite imagery to develop a database of cultivation sites, the researchers correlated site characteristics such as remoteness and erosion potential with the spread of agricultural frontiers.They report that, over the study period, cannabis cultivation sites in the study area nearly doubled in number, with total acreage under cultivation likewise nearly doubling, and that a significant portion of the new cultivation occurred in areas such as sensitive watersheds.They found, for example, that nearly 90% of the areas newly developed for cannabis cultivation had been covered in natural vegetation as late as 2006.The researchers argue that agricultural frontiers can develop “almost anywhere institutions fail to prevent” them — and note that, for 18 years after medicinal cannabis use became legal in California with the 1996 Compassionate Use Act, the state devoted no funds to regulating cannabis cultivation and production.In this issue of California Agriculture, Grantham and four co-authors from the North Coast Regional Water Quality Control Board present the results of their research into cannabis cultivators’ patterns of water use in several Northern California counties.For the research that resulted in “Watering the Emerald Triangle: Irrigation sources used by cannabis cultivators in Northern California” , Grantham and his colleagues analyzed reports submitted to the board by cannabis cultivators.The researchers determined how many cultivators sourced their water from wells, surface water diversions, spring diversions and other sources; how water sourcing behavior changed over the course of a year; and how water use patterns varied according to whether growers operated within the state’s legal cannabis market.The researchers determined that cannabis growers rely on well water to a greater degree than is generally supposed — and that their reliance on well water may increase as more growers join the legal market because of well water’s less restrictive permitting requirements.In separate research, Michael Polson — a postdoctoral researcher in UC Berkeley’s Department of Environmental Science, Policy, and Management — has investigated the environmental dimensions of cannabis from an anthropological perspective.In a paper published earlier this year, Polson shows how cannabis has been identified as an environmental problem that requires public intervention.On the basis of participant observation and more than 70 interviews with subjects across the cannabis spectrum — from park rangers to environmentalists to “criminalized people” — Polson demonstrates how cannabis production has been defined as pollution — “dovetail[ing] with [cannabis] prohibition’s history of marking people and substances as socially polluting.” Polson argues, as he highlights the legacy of cannabis prohibition in environmental debates, that policy making is at its most innovative when it includes a broad range of cultivators and when stigmas are explicitly addressed.Research into the environmental aspects of cannabis is also underway at UC Davis, where Mourad Gabriel is a research associate member in UCD’s School of Veterinary Medicine.In 2018, Gabriel and co-authors, including Robert Poppenga — a professor of molecular bio-sciences at the California Animal Health and Food Safety Lab at UC Davis — published the results of their research on the effects of rodenticides on owls in northwestern California forests.The researchers, working on privately owned timberland in Humboldt and Del Norte counties, investigated the prevalence of anticoagulant rodenticides in areas characterized by illegal cannabis cultivation.Anticoagulant rodenticides, used by some cannabis cultivators to control pests, are known to affect non-target species in urban areas and recently have been shown to affect carnivores in California’s remote forest areas as well.Gabriel and his coauthors undertook to determine whether the northern spotted owl, a threatened species, is exposed to anticoagulant rodenticides in the study area — and also to determine if barred owls, a common species, can be used as a surrogate to determine exposure levels in northern spotted owls.