Workplace secondhand smoke exposure in the U.S. trucking industry

The Prevalence of Exposure to Workplace Secondhand Smoke in the United States: 2010 to 2015

Objective

To compare changes in exposure to workplace secondhand smoke (SHS) by industry of employment and occupation from 2010 to 2015.

Methods

Data were collected from 2010 and 2015 National Health Interview Survey. Weighted estimates of the prevalence of exposure to workplace SHS among currently working nonsmokers in 2010 (n = 12 627) and 2015 (n = 16 399) were compared.

Results

The prevalence of exposure to workplace SHS among currently working nonsmokers was 10.0% in 2015 and 9.5% in 2010. Exposure to workplace SHS is disproportionally high among male workers, young workers, non-Hispanic blacks, Hispanics, workers with low education and low income, and workers residing in the Southern United States. Tobacco control policies have effectively reduced exposure to workplace SHS in a few white-collar and service job categories but blue-collar workers remain to have a high prevalence of exposure to workplace SHS. From 2010 to 2015, "transportation and warehousing industries" had the largest increase in SHS exposure (13.3%-21.5%, p value = .004) and "arts, entertainment, and recreation industries" had the largest decline in prevalence of exposure to SHS (20.1%-11.5%, p value = .01). In the multivariate analysis, workers with service (aOR = 1.4, p < .0001) and blue-collar occupations (aOR = 2.5, p < .0001) had a significantly higher prevalence of exposure to workplace SHS than those with white-collar occupations.

Conclusions

Disparities of SHS exposure by industry, occupation, and social demographic class continue to exist. Blue-collar workers, especially those working in "transportation and construction industries," along with young workers and workers in high risk social classes are priority groups for future workplace SHS prevention.

Implications

An estimated 12.6 million working nonsmokers were regularly exposed to SHS at work in 2015. We compared the changes in prevalence of exposure to workplace SHS from 2010 to 2015 by social demographic class, industry of employment and occupation. Our findings could help inform the policymakers and health practitioners to establish stronger smoke-free air laws and conduct education campaigns to reduce the exposure to workplace SHS, especially among certain industries and occupations with a disproportionally high prevalence of exposure to workplace SHS.

Temporal Trends of Secondhand Smoke Exposure: Nonsmoking Workers in the United States (NHANES 2001-2010)

BACKGROUND

The workplace is one of the major locations outside of the home for nonsmokers' exposure to secondhand smoke (SHS). New policies in many U.S. states and localities restrict or prohibit smoking in the workplace, and information on current trends in the exposure of nonsmokers to SHS across various occupational groups is therefore needed.

OBJECTIVE

We evaluated temporal trends in SHS exposure among nonsmoking workers in the United States and identified those occupations with workers with the highest levels of SHS exposure.

METHODS

We combined serum cotinine (sCOT) measurements and questionnaire data from five survey cycles of the National Health and Nutrition Examination Survey (NHANES: 2001-2010). Trends in SHS exposure by occupations were determined from percent changes and least-squares geometric means (LSGMs) of sCOT concentrations computed using sample-weighted multiple regression models.

RESULTS

Between NHANES 2001-2002 and NHANES 2009-2010, LSGMs of sCOT levels had changed -25% (95% CI: -39, -7%) in nonsmoking workers. The largest decrease was identified among food preparation workers [-54% (95% CI: -74, -19%)], followed by white-collar [-40%, (95% CI: -56, -19%)] and blue-collar workers (-32%, 95% CI: -51, -5%). LSGMs of sCOT remained highest in food preparation workers in all survey cycles, but the gap between occupations narrowed in the latest survey cycle (2009-2010). For example, the gap in LSGMs of sCOT between food preparation and science/education workers dropped > 70% during 2000 to 2010.

CONCLUSIONS

During the period from 2001 to 2010, the overall SHS exposure in nonsmoking workers declined with substantial drops in food preparation/service and blue-collar workers. Although disparities persist in SHS exposure, the gaps among occupations have narrowed.

CITATION

Wei B, Bernert JT, Blount BC, Sosnoff CS, Wang L, Richter P, Pirkle JL. 2016. Temporal trends of secondhand smoke exposure: nonsmoking workers in the United States (NHANES 2001-2010). Environ Health Perspect 124:1568-1574; http://dx.doi.org/10.1289/EHP165.

Exposure to second hand smoke at home and work among nonsmokers

Exposure to second hand smoke (SHS) is associated with adverse health effects. This study was undertaken to assess comparative levels of exposure to SHS at home and work among nonsmokers aged ⩾12 years. Data from National Health Examination Survey for 1999-2010 were analyzed to estimate exposure to SHS. Total number of subjects included in the study was 24,791. Those who self-reported not having used any tobacco products during the last five days were considered nonsmokers for the purpose of this study. Serum cotinine levels were used as the outcome variable to indicate the level of exposure to SHS. Adjusted serum cotinine levels for those with no exposure to SHS, exposure to SHS at work only, exposure to SHS at home only, and exposure to SHS at home and work were 0.047 (0.044-0.050)n g/mL, 0.055 (0.047-0.064) ng/mL, 0.522 (0.401-0.678) ng/mL, and 0.485 (0.280-0.0840) ng/mL respectively. Public efforts to reduce exposure to SHS at home should be strengthened.

Dietary fiber intake modifies the association between secondhand smoke exposure and coronary heart disease mortality among Chinese non-smokers in Singapore

OBJECTIVE

Secondhand smoke (SHS) exposure increases the risk for coronary heart disease (CHD) by an estimated 25% to 30% via oxidative stress and inflammatory mechanisms that may be ameliorated by dietary components. The aim of this study was to evaluate the hypothesized modifying role of nutrients with known antioxidant and/or anti-inflammatory properties on the relationship between SHS exposure and CHD mortality.

METHODS

Detailed SHS exposure and dietary information was collected among 29,579 non-smokers in the Singapore Chinese Health Study, a prospective population-based cohort. The evaluation of whether or not dietary factors (β-cryptoxanthin, lutein, ω-3 polyunsaturated fatty acids, fiber, isothiocyanates, and soy isoflavones) modified the relationship between SHS exposure and CHD mortality was conducted within multivariable Cox proportional hazards models by creating an interaction term between the potential dietary effect modifier (lowest quartile of intake versus the second through fourth quartiles of intake) and the SHS exposure (none versus living with at least one smoker[s]).

RESULTS

Evidence for a main-effects association between SHS exposure and risk for CHD mortality was not observed. In stratified analyses by levels of selected dietary nutrient intake, fiber modified the effects of SHS exposure on risk for CHD mortality (P for interaction = 0.02). The adjusted hazards ratio for SHS exposure (living with at least one smoker[s] versus living with no smokers) and CHD mortality was 1.62 (95% confidence interval, 1.00-2.63) for those with low-fiber intake. In contrast, among those with high-fiber intake, there was no association with SHS exposure.

CONCLUSION

We provide evidence that a diet high in fiber may ameliorate the harmful effects of SHS exposure on risk for CHD mortality.

A cross-sectional study of secondhand smoke exposure and respiratory symptoms in non-current smokers in the U.S. trucking industry: SHS exposure and respiratory symptoms

BACKGROUND

Previous studies have suggested associations of adult exposures to secondhand smoke (SHS) with respiratory symptoms, but no study has focused on blue-collar industrial environments. We assessed the association between SHS and respiratory symptoms in 1,562 non-current smoking U.S. trucking industry workers.

METHODS

Information on SHS exposure and respiratory health was obtained by questionnaire. Multiple logistic regression analyses were used to assess the associations of recent and lifetime exposures to SHS with chronic phlegm, chronic cough, and any wheeze, defined by American Thoracic Society criteria.

RESULTS

In analyses adjusted for age, gender, race, childhood SHS exposure, former smoking, pack-years of smoking and years since quitting, body mass index, job title, region of the country, and urban residence, recent exposures to SHS were associated with all three respiratory symptoms (odds ratio (OR) = 1.46; 95% confidence interval (CI) = 1.00-2.13) for chronic cough, 1.55 (95% CI = 1.08-2.21) for chronic phlegm, and 1.76 (95% CI = 1.41-2.21) for any wheeze). Workplace exposure was the most important recent exposure. Childhood exposure to SHS was also associated with all three symptoms, but only statistically significantly for chronic phlegm (OR = 1.84; 95% CI = 1.24-2.75). Additional years of living with a smoker were associated with an increased risk, but there was no evidence of a dose-response, except for chronic phlegm.

CONCLUSIONS

In this group of trucking industry workers, childhood and recent exposures to SHS were related to respiratory symptoms.

Plasma fluorescent oxidation products and short-term occupational particulate exposures

BACKGROUND

Evidence suggests that fine particulate air pollution results in oxidative induced tissue damage.

METHODS

A global fluorescent oxidation products (FLOx) assay (fluorescent intensity (FI) units per milliliter of plasma) was measured in blood samples collected from 236 nonsmoking, Caucasian, male trucking industry workers either prior to, during, or after their work shifts. Occupational exposures to particulate matter (PM)(2.5) were based on job-specific area-level sampling. Generalized linear models were used to determine associations between FLOx levels and PM(2.5) , adjusted for age, time since last meal, alcohol consumption, aspirin, and cholesterol medications.

RESULTS

The mean (standard deviation) level of FLOx was 265.9 FI/ml (96.0). Levels of FLOx were higher among older individuals and lower among those who had consumed alcohol in the past 24 hr. However, no associations were observed between FLOx and PM(2.5) .

CONCLUSIONS

Our results indicate no association between occupational PM(2.5) exposure and this marker of global oxidative stress.

Respiratory and immune response to maximal physical exertion following exposure to secondhand smoke in healthy adults

We assessed the cardiorespiratory and immune response to physical exertion following secondhand smoke (SHS) exposure through a randomized crossover experiment. Data were obtained from 16 (8 women) non-smoking adults during and following a maximal oxygen uptake cycling protocol administered at baseline and at 0-, 1-, and 3- hours following 1-hour of SHS set at bar/restaurant carbon monoxide levels. We found that SHS was associated with a 12% decrease in maximum power output, an 8.2% reduction in maximal oxygen consumption, a 6% increase in perceived exertion, and a 6.7% decrease in time to exhaustion (P<0.05). Moreover, at 0-hours almost all respiratory and immune variables measured were adversely affected (P<0.05). For instance, FEV₁ values at 0-hours dropped by 17.4%, while TNF-α increased by 90.1% (P<0.05). At 3-hours mean values of cotinine, perceived exertion and recovery systolic blood pressure in both sexes, IL4, TNF-α and IFN-γ in men, as well as FEV₁/FVC, percent predicted FEV₁, respiratory rate, and tidal volume in women remained different compared to baseline (P<0.05). It is concluded that a 1-hour of SHS at bar/restaurant levels adversely affects the cardiorespiratory and immune response to maximal physical exertion in healthy nonsmokers for at least three hours following SHS.

Exposure to particulate matters (PM2.5) and airborne nicotine in computer game rooms after implementation of smoke-free legislation in South Korea

INTRODUCTION

In South Korea, computer game rooms are subject to regulations mandating a designated nonsmoking area pursuant to Article 7 of the Enforcement Rules of the National Health Promotion Act; nonsmoking areas must be enclosed on all sides by solid and impermeable partitions.

METHODS

Using PM(2.5) monitors (SidePak AM510) and airborne nicotine monitors, we measured concentrations in smoking and nonsmoking areas to examine whether separation of the nonsmoking areas as currently practiced is a viable way to protect the nonsmoking area from secondhand smoke exposure. Convenient samplings were conducted at 28 computer game rooms randomly selected from 14 districts in Seoul, South Korea between August and September 2009.

RESULTS

The medians (interquartile range) of PM(2.5) concentrations in smoking and nonsmoking areas were 69.3 μg/m(3) (34.5-116.5 μg/m(3)) and 34 μg/m(3) (15.0-57.0 μg/m(3)), while those of airborne nicotine were 0.41 μg/m(3) (0.25-0.69 μg/m(3)) and 0.12 μg/m(3) (0.06-0.16 μg/m(3)), respectively. Concentrations of airborne nicotine and PM(2.5) in nonsmoking areas were substantially positively associated with those in smoking areas. The Spearman correlation coefficients for them were 0.68 (p = .02) and 0.1 (p = 0.7), respectively. According to our modeling result, unit increase of airborne nicotine concentration in a smoking area contributed to 7 (95% CI = 2.5-19.8) times increase of the concentration in the adjacent nonsmoking area after controlling for the degree of partition left closed and the indoor space volume.

CONCLUSIONS

Our study thus provides evidence for the introduction of more rigorous policy initiatives aimed at encouraging a complete smoking ban in such venues.