Smoke-free workplaces substantially reduce exposure to secondhand smoke and the associated cardiovascular risks for passive smokers. Smoke-free workplaces also reduce cigarette consumption among smoking employees by 29% by making it easier for them to quit or reduce consumption . However, only about 69% of U.S. indoor workers reported being covered by a smoke free workplace policy in 1999 . Because the risks of myocardial infarction fall rapidly after smoking cessation and, presumably, after reduced exposure to secondhand smoke, we projected the cardiovascular health and economic effects if all remaining U.S. workplaces were made smoke free.The indoor worker sample that was not covered by a smoke-free workplace policy was estimated by multiplying the total indoor worker sample by the percentage of workers lacking such coverage . This cohort was then divided into active and passive smokers by multiplying the indoor worker sample lacking smoke-free workplace policy coverage by the smoking prevalence for adults aged 18 to 64 years . This prevalence was calculated by multiplying age-specific smoking prevalence by the respective age cohort from the 2000 Census . Nonsmoking indoor workers lacking smoke-free workplace policy coverage were defined as passive smokers.The 29% reduction in total cigarette consumption when a workplace becomes smoke free is a result of a 3.8% reduction in absolute smoking prevalence and a 1.3 cigarette per day reduction in daily consumption among continuing smokers. The resultant quitter sample was calculated by multiplying the percentage of quitters by the active smoker indoor worker sample.
We assumed that quitting occurred immediately following policy introduction . We made several assumptions about passive smoking. First, a national smoke-free workplace policy immediately eliminates passive smoking in all workplaces currently not covered by a policy . Second,vertical cannabis grow passive smokers who work indoors are not exposed to passive smoking outside of work. Finally, we did not account for reductions in passive smoking outside of the workplace, at home, or in other locations.The 2000 U.S. adult per capita cigarette consumption was 104.3 packs per year . The 2000 adult smoker per capita cigarette consumption is equal to the adult per capita cigarette consumption divided by the adult smoking prevalence , or 447.6 packs per year. The annual reduction in cigarette consumption due to a nationwide smoke-free workplace policy is equal to the consumption forgone by quitters plus the consumption reduction among remaining smokers. The consumption forgone by quitters is the number of quitters multiplied by the 2000 adult smoker per capita consumption. The consumption reduction is the number of remaining smokers multiplied by both the 2000 adult smoker per capita consumption and the 12.2% reduction in cigarette consumption. The 2000 pretax price of a pack of cigarettes was $2.36 . The total pretax value of forgone cigarette consumption to the tobacco industry is equal to the total number of forgone packs multiplied by the pretax pack price.The number of prevented deaths was the sum of prevented immediate deaths and prevented deaths within a given year following the event. Prevented immediate deaths were the product of the number of prevented events and the probability of immediate death from the event. Prevented deaths within 1 year of the initial event were the difference between the number of prevented events and the number of prevented immediate deaths, multiplied by the survival probability. These deaths were then adjusted to account for gradual reduction in risk over time using the midpoint methodology listed previously. The immediate mortality rate for myocardial infarction was 0.115 for men and 0.167 for women ; the rate for stroke was 0.043 . The annual survival probability was 0.992 for men at risk of acute myocardial infarction and 0.995 for women, and 0.993 for persons at risk of stroke .
The annual survival probability in the first year after a myocardial infarction was 0.812 for men and 0.765 for women; after a stroke, the probability was 0.663 . The annual survival probability in subsequent years following a myocardial infarction was 0.994 for men and 0.933 for women; for stroke, the probability was 0.961 . Steady-state results were calculated by advancing this cohort through time. For each subsequent year, the surviving cohort was calculated by multiplying the previous cohort by the annual survival probability. This new cohort was then multiplied by the event incidence and by the difference between relative risks from the prior year and the current year. Prevented total events, immediate deaths, and total deaths were calculated as described previously. Savings from the prior years were also calculated after multiplying the prior cohort by the annual survival probabilities. Due to the midpoint correction, half of the sample was multiplied by the annual survival probability one more time than its corresponding other sample half in each time period. A Monte Carlo simulation was performed to estimate the distribution of the reduction in cardiovascular events. Ten thousand trials were generated. Individual parameters that were varied simultaneously in the simulation included the percentage of workers covered by smoke-free workplace policies,smoking prevalence, effect of smoke-free workplace policies on quitting, initial and steady-state relative risks of myocardial infarctions and strokes, initial relative risk of myocardial infarction among passive smokers, and incidence of myocardial infarctions and strokes . The steady-state relative risk of myocardial infarctions among passive smokers was not varied. Normal distributions were used, except for relative risks that had a log-normal distribution . We report our findings by using the median of the Monte Carlo simulation. The 2.5% and 97.5% points in the distribution are reported .We found that making workplaces smoke free not only reduces worker exposure to secondhand smoke, but also contributes substantially to reducing cardiovascular disease among nonsmokers and smokers. Nonsmokers who are no longer exposed to secondhand smoke realize 60% of the benefit and smokers who quit realize 40% of the benefit.
Although passive smokers have a lower risk of heart disease than do smokers, the sample at risk is nearly three times larger than the active smoking sample. In addition, smoke-free workplaces eliminate risks to all passive smokers even though they only lead some active smokers to quit entirely. This analysis underestimates the true cost of cardiovascular disease due to smoking. We made no estimates of stroke reduction among passive smokers, nor did we include any indirect savings from prevented lost work productivity. In addition, we did not estimate the health and resultant economic effects of reduced consumption among remaining smokers,commercial drying room as well as the effects on reductions in passive smoking that occur outside of the workplace.Although we used a uniform estimate for smoking prevalence and smoke-free workplace coverage in this analysis, smoking prevalence and smoke-free workplace coverage varies by occupation . Blue-collar and service workers are more likely to smoke and less likely to be covered by a smoke-free workplace policy compared with white-collar workers . Smoke-free workplaces also lead to greater reductions in smoking prevalence among blue-collar and service workers compared with white collar workers . Since smoke-free workplace policy effects are based primarily on white-collar workers, we may have underestimated the effect of a national smoke free workplace policy because a larger proportion of the affected persons would be blue-collar and service workers. This underestimation is counterbalanced by the smaller fractions of blue-collar passive smokers and blue collar indoor workers. Unfortunately, the most recent estimates of smoking prevalence, smoke-free workplace coverage, and smoke-free workplace effect by occupation are 10 years old, from the 1992–1993 Current Population Survey . As a result, we did not use occupation specific rates in this analysis. Our analysis may also overestimate the effect of a national smoke-free workplace policy given recent increases in smoke-free workplace policies. Data from selected states in 2000 indicate that there have been increases in smoke-free workplace coverage compared with the 1999 data used for this analysis . Furthermore, findings from our model may have been affected by improvements in treatments for cardiovascular disease. However, improvements in care may also be more costly, in which case prevention of cardiovascular events may result in further health care savings. Not all persons are regular smokers; some are occasional smokers. This analysis does not directly address this issue as we could not differentiate between occasional smokers and regular smokers. Occasional smoker consumption was folded in with all smokers, and likely contributed to some of the quitting behavior seen with smoke-free workplaces. Previous research has shown a correlation between more comprehensive smoke-free workplace policies and either staying an occasional smoker or becoming a former smoker 1 year following implementation of a smoke-free workplace policy . Smoke-free workplace policies are also associated with reductions in youth smoking prevalence and consumption . These reductions exceed expected reductions from working teenagers, suggesting that these policies have additional indirect effects, such as alterations of social norms, and thus will have long-run effects on reducing heart disease mortality by reducing the number of new smokers.
While smoke-free workplaces yield substantial health benefits in terms of cardiovascular disease, the tobacco industry would also be substantially affected by a nationwide smoke-free workplace policy. Over 900 million cigarette packs would go unsmoked, and the tobacco industry at large would lose over $2.3 billion in revenue every year. This substantial cost to the tobacco industry explains why it opposes these measures so vigorously. Legislation is the best way to create smoke-free workplaces. Although this analysis addresses the hypothetical case of making all U.S. workplaces smoke free at once, action at the state or national level is least likely to provide strong smoke-free legislation due to the massive ability of the tobacco industry to make campaign contributions and hire well-connected lobbyists. Such legislation is generally best done at the local level, where public health forces are relatively strong and the tobacco industry’s influence is relatively weak .Watercress is a leafy-green crop in the Brassicaceae family, consumed widely across the world for its peppery taste and known to be the most nutrient dense salad leaf . The peppery taste is the result of high concentrations of glucosinolates – phytochemicals which can be hydrolyzed to isothiocyanates upon plant tissue damage, such as chewing, known for their potent anticancer , anti-inflammatory , and antioxidant effects that are beneficial to human health. Although ITCs are the main products of digestion depending on pH, metal ions, and other epithiospecifier proteins, nitriles can also be formed through GLS break-down and they too may have chemopreventitive properties . Watercress is high value horticultural crop. A specialty leafy vegetable, with a growing area of 282 ha in the US, with 75 ha of production in California, compared to 58 ha in the UK . It is also a high-value horticultural crop in the UK, with the market value of £8.90 per kg compared to £4.97 per kg for mixed baby leaf salad bags and represents a total value of £15 million per year . Watercress is traditionally grown in outdoor aquatic systems, but there is increasing interest in its suitability for indoor hydroponic systems, such as in vertical farms . VF utilize hydroponic or aeroponic systems that allow plant stacking in multiple vertical or horizontal layers increasing the effective use of space and other resources, particularly water . Indoor vertical agriculture is well-suited to the production of leafy greens. Their fast growth rate, high harvest index, low photosynthetic energy demand and compact shape make them ideal for indoor farming technologies . VFs have multi-layered indoor crop production space with the use of artificial lights and soilless cultivation systems. With the capacity to control lighting, ventilation, irrigation, nutrient levels, and abiotic stress, VFs offer the potential of high and predictable yields and uniform produce alongside reduced water use and often no pesticide applications whatsoever . The future of indoor food production is likely to include other high-value horticultural crops such as several leafy greens, culinary herbs, strawberries, and flowers. Breeding targets for these crops include short life cycles, low energy demands, improved yield , small root systems, as well novel sensory and nutritional profiles . VF systems are gaining traction for commercial scale cultivation, partly due to their ability to deliver locally-grown food to urban areas, with lower environmental costs and also to deliver food in locations where fresh produce cannot be easily grown .