Passive smoking and 20-year cardiovascular disease mortality among nonsmoking wives, Evans County, Georgia

Association of exposure to environmental tobacco smoke at home and risk of mortality among US never smokers by race/ethnicity, education, and income

Environmental tobacco smoke (ETS) increases the risk of mortality among nonsmokers. Yet, few studies have examined this association among racial/ethnic minorities or among people with less education or income. We assessed self-reported ETS exposure at home among never smoking participants (n = 110,945) of the 1991-2010 National Health Interview Surveys. Deaths through 2015 were identified by the National Death Index. Hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality were estimated using Cox proportional hazards regression models with age as the underlying time metric and adjusted for sex, race/ethnicity, education, household income, body mass index, region of residence, and survey year. We further stratified all-cause mortality analyses by race/ethnicity, household income, and education. Relative to no ETS at home, every day exposure was associated with higher risk of all-cause mortality (HR = 1.33, 95%CI: 1.23, 1.45), with similar HRs observed across strata of education and income. HRs were similar among non-Hispanic Black (HR = 1.28, 95%CI: 1.08, 1.53) and non-Hispanic White adults (HR = 1.34, 95%CI: 1.21, 1.48) although somewhat higher among Hispanic adults (HR = 1.65, 95%CI: 1.29, 2.10; P for pairwise comparison = 0.04). ETS exposure at home is an important contributor to mortality across strata of race/ethnicity, education, and income in the US.

Mortality of Enlisted Men Who Served on Nuclear-Powered Submarines in the United States Navy

OBJECTIVE

To describe the long-term mortality experience of a cohort of enlisted men who served on nuclear-powered submarines in the United States Navy and breathed recirculated filtered air for extended periods of time.

METHODS

In this historical cohort study we estimated standardized mortality ratios (SMRs) and used within-cohort Poisson regression analyses to address healthy worker biases.

RESULTS

Three thousand two hundred sixty three deaths occurred among 85,498 men during 1,926,875 person-years of follow-up from 1969 to 1995. SMRs were reduced for most cause-of-death categories, prostate cancer had a twofold elevation. In within-cohort comparisons, prostate cancer mortality did not increase with duration of submarine service, but ischemic heart disease mortality increased 26% per 5 years of submarine service.

CONCLUSIONS

Long periods of submarine service do not increase mortality in most cause-of-death categories. Increased mortality from ischemic heart disease likely reflects the effects of tobacco smoke.

Environmental tobacco smoke exposure and heart disease: A systematic review

AIM

To review evidence relating passive smoking to heart disease risk in never smokers.

METHODS

Epidemiological studies were identified providing estimates of relative risk (RR) of ischaemic heart disease and 95%CI for never smokers for various indices of exposure to environmental tobacco smoke (ETS). “Never smokers” could include those with a minimal smoking experience. The database set up included the RRs and other study details. Unadjusted and confounder-adjusted RRs were entered, derived where necessary using standard methods. The fixed-effect and random-effects meta-analyses conducted for each exposure index included tests for heterogeneity and publication bias. For the main index (ever smoking by the spouse or nearest equivalent, and preferring adjusted to unadjusted data), analyses investigated variation in the RR by sex, continent, period of publication, number of cases, study design, extent of confounder adjustment, availability of dose-response results and biomarker data, use of proxy respondents, definitions of exposure and of never smoker, and aspects of disease definition. Sensitivity analyses were also run, preferring current to ever smoking, or unadjusted to adjusted estimates, or excluding certain studies.

RESULTS

Fifty-eight studies were identified, 20 in North America, 19 in Europe, 11 in Asia, seven in other countries, and one in 52 countries. Twenty-six were prospective, 22 case-control and 10 cross-sectional. Thirteen included 100 cases or fewer, and 11 more than 1000. For the main index, 75 heterogeneous (P < 0.001) RR estimates gave a combined random-effects RR of 1.18 (95%CI: 1.12-1.24), which was little affected by preferring unadjusted to adjusted RRs, or RRs for current ETS exposure to those for ever exposure. Estimates for each level of each factor considered consistently exceeded 1.00. However, univariate analyses revealed significant (P < 0.001) variation for some factors. Thus RRs were lower for males, and in North American, larger and prospective studies, and also where the RR was for spousal smoking, fatal cases, or specifically for IHD. For case-control studies RRs were lower if hospital/diseased controls were used. RRs were higher when diagnosis was based on medical data rather than death certificates or self-report, and where the never smoker definition allowed subjects to smoke products other than cigarettes or have a limited smoking history. The association with spousal smoking specifically (1.06, 1.01-1.12, n = 34) was less clear in analyses restricted to married subjects (1.03, 0.99-1.07, n = 23). In stepwise regression analyses only those associations with source of diagnosis, study size, and whether the spouse was the index, were independently predictive (at P < 0.05) of heart disease risk. A significant association was also evident with household exposure (1.19, 1.13-1.25, n = 37). For those 23 studies providing dose-response results for spouse or household exposure, 11 showed a significant (P < 0.05) positive trend including the unexposed group, and two excluding it. Based on fewer studies, a positive, but non-significant (P > 0.05) association was found for workplace exposure (RR = 1.08, 95%CI: 0.99-1.19), childhood exposure (1.12, 0.95-1.31), and biomarker based exposure indices (1.15, 0.94-1.40). However, there was a significant association with total exposure (1.23, 1.12-1.35). Some significant positive dose-response trends were also seen for these exposure indices, particularly total exposure, with no significant negative trends seen. The evidence suffers from various weaknesses and biases. Publication bias may explain the large RR (1.66, 1.30-2.11) for the main exposure index for smaller studies (1-99 cases), while recall bias may explain the higher RRs seen in case-control and cross-sectional than in prospective studies. Some bias may also derive from including occasional smokers among the “never smokers”, and from misreporting smoking status. Errors in determining ETS exposure, and failing to update exposure data in long term prospective studies, also contribute to the uncertainty. The tendency for RRs to increase as more factors are adjusted for, argues against the association being due to uncontrolled confounding.

CONCLUSION

The increased risk and dose-response for various exposure indices suggests ETS slightly increases heart disease risk. However heterogeneity, study limitations and possible biases preclude definitive conclusions.

Risk of all-cause mortality and cardiovascular disease associated with secondhand smoke exposure: a systematic review and meta-analysis

BACKGROUND

Emerging studies have assessed the association between secondhand smoke (SHS) exposure and cardiovascular disease (CVD) as well as all-cause mortality. However, findings were not consistent due to the heterogeneity of study characteristics.

METHODS

PubMed and Embase were searched through May 2014 for prospective cohort and case-control studies investigating the associations of SHS exposure in never smokers with all-cause mortality and the risk of CVD. The main analysis was performed in studies using self-reported SHS exposure and secondary analysis was performed in studies using objectively measured SHS exposure. Summary estimates were calculated using random-effects models.

RESULTS

Twenty-three prospective and 17 case-control studies were included. The pooled relative risks (RR) for never smokers exposed to SHS in comparison with those unexposed were 1.18 [95% confidence interval (CI): 1.10-1.27] for all-cause mortality (12 studies), and 1.23 (1.16-1.31) for CVD (38 studies). The association of SHS exposure with CVD was markedly stronger among studies conducted in China (RR=1.65, 95% CI 1.27-2.13) than that in the US (RR=1.09, 95% CI 1.03-1.16). Studies using objectively measured SHS exposure demonstrated a slightly higher risk for CVD compared with those using self-reported SHS exposure.

CONCLUSIONS

Exposure to SHS significantly increased the risk for all-cause mortality and CVD. The risk associated with SHS exposure was large in China while the risk was only modest in the US. Studies using objectively measured SHS exposure may yield a higher risk of CVD than those using self-reported SHS exposure.

Secondhand tobacco smoke exposure and heart rate variability and inflammation among non-smoking construction workers: a repeated measures study

BACKGROUND

Although it has been well recognized that exposure to secondhand tobacco smoke (SHS) is associated with cardiovascular mortality, the mechanisms and time course by which SHS exposure may lead to cardiovascular effects are still being explored.

METHODS

Non-smoking workers were recruited from a local union and monitored inside a union hall while exposed to SHS over approximately 6 hours. Participants were fitted with a continuous electrocardiographic monitor upon enrollment which was removed at the end of a 24-hr monitoring period. A repeated measures study design was used where resting ECGs and blood samples were taken from individuals before SHS exposure (baseline), immediately following SHS exposure (post) and the morning following SHS exposure (next-morning).Inflammatory markers, including high sensitivity C-reactive protein (CRP) and white blood cell count (WBC) were analyzed. Heart rate variability (HRV) was analyzed from the ECG recordings in time (SDNN, rMSSD) and frequency (LF, HF) domain parameters over 5-minute periods. SHS exposure was quantified using a personal fine particulate matter (PM2.5) monitor.Linear mixed effects regression models were used to examine within-person changes in inflammatory and HRV parameters across the 3 time periods. Exposure-response relationships with PM2.5 were examined using mixed effects models. All models were adjusted for age, BMI and circadian variation.

RESULTS

A total of 32 male non-smokers were monitored between June 2010 and June 2012. The mean PM2.5 from SHS exposure was 132 μg/m3. Immediately following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with declines in HRV (7.8% [standard error (SE) =3%] SDNN, 8.0% (SE = 3.9%) rMSSD, 17.2% (SE = 6.3%) LF, 29.0% (SE = 10.1%) HF) and increases in WBC count 0.42 (SE = 0.14) k/μl. Eighteen hours following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with 24.2% higher CRP levels.

CONCLUSIONS

Our study suggest that short-term SHS exposure is associated with significantly lower HRV and higher levels of inflammatory markers. Exposure-associated declines in HRV were observed immediately following exposure while higher levels of CRP were not observed until 18 hours following exposure. Cardiovascular autonomic and inflammation responses may contribute to the pathophysiologic pathways that link SHS exposure with adverse cardiovascular outcomes.

Second-hand tobacco smoke and cardiovascular disease risk: an epidemiological review

In this review, we have sought to examine the epidemiological, basic science, and public health data regarding the association between second-hand smoke (SHS) exposure and the development of coronary heart disease (CHD). SHS increases the risk of CHD by 25-30% according to multiple cohort, case-control, and meta-analytical studies. Physiologic and basic science research suggest that the mechanisms by which SHS affects the cardiovascular system are multiple and include increased thrombogenesis and low-density lipoprotein oxidation, decreased exercise tolerance, dysfunctional flow-mediated vasodilatation, and activation of inflammatory pathways with concomitant oxidative damage and impaired vascular repair. As a result, chronic exposure promotes atherogenesis and the development of cardiovascular disease, increasing the risk of having an acute coronary syndrome (ACS). With the implementation of statewide and nationwide public smoke-free legislation across the United States and Europe, respectively, over the last 10-15 years, there has been a significant and reciprocal decline in the incidence of emergency admissions for ACS by an average 17% despite persistent attempts on the part of the tobacco industry to diminish the correlation between SHS exposure and CHD. These findings underscore the importance of the effects of smoking legislation on community health.

Secondhand tobacco smoke exposure and associated factors among college students on campus and in the home: a preliminary study

To explore the prevalence of secondhand tobacco smoke (SHS) exposure of college students at two locations, i.e., on campus and in the home, and to identify factors associated with SHS exposure at each location, a preliminary cross-sectional study was conducted on 1754 nonsmoking students from two universities in Korea. In total, 83.1% were exposed to SHS at least once a week on campus or at home; the average SHS exposure was 3.4 times per week. Specifically, 79.7% and 23.5% were exposed to SHS on campus and in the home, respectively. On campus, SHS exposure was significantly more prevalent in freshmen and sophomore students. In the home, SHS exposure was significantly more prevalent among females, those with smokers in their families, and those who rated their health as poor. SHS exposure was common among nonsmoking college students, with more than two-thirds exposed on campus. The prevalence of SHS exposure was greater on campus than in the home; the factors associated with SHS exposure were location-specific.

Work-related risk factors of myocardial infarction

OBJECTIVES

The aim of the study was to find out which occupational factors account for the risk of the myocardial infarction.

MATERIAL AND METHODS

A questionnaire survey was performed during the period of one calendar year in all patients (1053 subjects, 692 men and 361 women) hospitalized at the Medical University of Łódź because of the first myocardial infarction. The questionnaire was prepared especially for the purpose of this study and consisted of two parts. The first part comprised: demographic data, health status at admittance, traditional risk factors for the ischaemic heart disease and was filled-in by physicians. Part II was done by occupational hygiene specialists and referred to education, job title and characteristics, employment data, self assessment of work-related and general stress, fatigue, socio-economic status, physical activity, alcohol intake, tobacco smoking, dietary habits.

RESULTS

Mean age in the study group was 59.9 ± 10.4 years (26-85 years), 58.7 ± 10.0 (26-84 years) for men and 62.3 ± 10.7 (32-85 years) for women, employment duration was 32.9±8.8 (4-65 years), for men 34.0 ± 8.6 (5-65 years), for women 30.7 ± 8.8 (4-60 years. Most of myocardial infarction cases both in the group of men and women were noted in the age interval 56-60 years, 22.3% vs. 17.4%, respectively. The majority of examined men were farmers, low and middle management and self-employed workers. Among women prevailed clerks, seamstresses and farmers. The most frequent occupational risk factors were: work-related stress, experienced by 54.2% of the examined subjects, occupational noise (45,5%), dust (41,7%) and various chemical factors (33%). A majority of the study group (76.5% women and 54.4% men) linked the cardiac infarction with stress, while 39.1% men vs. 16.5% women correlated it with physical effort.

CONCLUSION

Our studies indicate that, among a wide spectrum of occupational factors, stress, noise and fine particulate dust are major contributors to the increased risk of myocardial infarction.

Combined impact of lifestyle-related factors on total and cause-specific mortality among Chinese women: prospective cohort study

BACKGROUND

Although cigarette smoking, excessive alcohol drinking, obesity, and several other well-studied unhealthy lifestyle-related factors each have been linked to the risk of multiple chronic diseases and premature death, little is known about the combined impact on mortality outcomes, in particular among Chinese and other non-Western populations. The objective of this study was to quantify the overall impact of lifestyle-related factors beyond that of active cigarette smoking and alcohol consumption on all-cause and cause-specific mortality in Chinese women.

METHODS AND FINDINGS

We used data from the Shanghai Women's Health Study, an ongoing population-based prospective cohort study in China. Participants included 71,243 women aged 40 to 70 years enrolled during 1996-2000 who never smoked or drank alcohol regularly. A healthy lifestyle score was created on the basis of five lifestyle-related factors shown to be independently associated with mortality outcomes (normal weight, lower waist-hip ratio, daily exercise, never exposed to spouse's smoking, higher daily fruit and vegetable intake). The score ranged from zero (least healthy) to five (most healthy) points. During an average follow-up of 9 years, 2,860 deaths occurred, including 775 from cardiovascular disease (CVD) and 1,351 from cancer. Adjusted hazard ratios for mortality decreased progressively with an increasing number of healthy lifestyle factors. Compared to women with a score of zero, hazard ratios (95% confidence intervals) for women with four to five factors were 0.57 (0.44-0.74) for total mortality, 0.29 (0.16-0.54) for CVD mortality, and 0.76 (0.54-1.06) for cancer mortality. The inverse association between the healthy lifestyle score and mortality was seen consistently regardless of chronic disease status at baseline. The population attributable risks for not having 4-5 healthy lifestyle factors were 33% for total deaths, 59% for CVD deaths, and 19% for cancer deaths.

CONCLUSIONS

In this first study, to our knowledge, to quantify the combined impact of lifestyle-related factors on mortality outcomes in Chinese women, a healthier lifestyle pattern-including being of normal weight, lower central adiposity, participation in physical activity, nonexposure to spousal smoking, and higher fruit and vegetable intake-was associated with reductions in total and cause-specific mortality among lifetime nonsmoking and nondrinking women, supporting the importance of overall lifestyle modification in disease prevention. Please see later in the article for the Editors' Summary.

Environmental tobacco smoke and coronary heart disease mortality in the United States--a meta-analysis and critique

Several major meta-analyses have concluded that exposure to environmental tobacco smoke (ETS) increases the risk of coronary heart disease (CHD) by about 25% among never smokers. However, these reviews have excluded a large portion of the epidemiologic evidence on questionable grounds and have been inconsistent in the selection of the results that are included. We conducted an updated meta-analysis and critique of the evidence on ETS exposure and its relationship to death from CHD among never smokers. Our focus is on the U.S. cohort studies, which provide the vast majority of the available evidence. ETS exposure is assessed in terms of spousal smoking, self-reported estimates, and personal monitoring. The epidemiologic results are summarized by means of overall relative risks and dose-response relationships. The methodological issues of publication bias, exposure misclassification, and confounding are discussed. Several large studies indicate that spousal smoking history is a valid measure of relative exposure to ETS, particularly for females. Personal monitoring of nonsmokers indicates that their average ETS exposure from a smoking spouse is equivalent in terms of nicotine exposure to smoking less than 0.1 cigarettes per day. When all relevant studies are included in the meta-analysis and results are appropriately combined, current or ever exposure to ETS, as approximated by spousal smoking, is associated with roughly a 5% increased risk of death from CHD in never smokers. Furthermore, there is no dose-response relationship and no elevated risk associated with the highest level of ETS exposure in males or females. An objective assessment of the available epidemiologic evidence indicates that the association of ETS with CHD death in U.S. never smokers is very weak. Previous assessments appear to have overestimated the strength of the association.

Cardiovascular effects of secondhand smoke: nearly as large as smoking

BACKGROUND

Secondhand smoke increases the risk of coronary heart disease by approximately 30%. This effect is larger than one would expect on the basis of the risks associated with active smoking and the relative doses of tobacco smoke delivered to smokers and nonsmokers.

METHODS AND RESULTS

We conducted a literature review of the research describing the mechanistic effects of secondhand smoke on the cardiovascular system, emphasizing research published since 1995, and compared the effects of secondhand smoke with the effects of active smoking. Evidence is rapidly accumulating that the cardiovascular system--platelet and endothelial function, arterial stiffness, atherosclerosis, oxidative stress, inflammation, heart rate variability, energy metabolism, and increased infarct size--is exquisitely sensitive to the toxins in secondhand smoke. The effects of even brief (minutes to hours) passive smoking are often nearly as large (averaging 80% to 90%) as chronic active smoking.

CONCLUSIONS

The effects of secondhand smoke are substantial and rapid, explaining the relatively large risks that have been reported in epidemiological studies.

Environmental tobacco smoke: association with cardiovascular function at rest and during stress

Chronic exposure to environmental tobacco smoke (ETS) contributes to cardiovascular disease morbidity and mortality, and ETS alters cardiovascular performance during exercise stress. However, no study has examined whether those with ETS exposure have altered cardiovascular functioning during psychological stress, relative to those with no substantial ETS exposure. Seventy-eight healthy, nonsmoking adult men with either high levels of current ETS exposure at home and work or no current or significant lifetime ETS exposure were tested in a stress reactivity protocol. Blood pressure and heart rate were monitored during rest and during two psychological stressors. Those with high ETS exposure had significantly elevated heart rate and blood pressure at baseline, relative to those with no exposure. The groups did not differ on their cardiovascular stress responses. These data suggest that chronic ETS exposure is associated with altered cardiovascular functioning at rest, but not during stress. Results are discussed with regard to the role of ETS on the development of heart disease among nonsmokers.

Passive cigarette smoking increases isoprostane formation

Passive smoking has been demonstrated to exert a variety of deleterious effects eventually resulting in vascular damage. Isoprostanes, a reliable marker of in vivo oxidation injury, have been shown to increase in active cigarette smoking. Data for passive smoking are lacking. We were examining the isoprostane 8-epi-PGF2alpha in 12 smokers and non-smokers exposed daily to passive cigarette smoke for 12 days. Plasma samples stored at liquid nitrogen from people having been examined earlier were used. Prevalues of 8-epi-PGF2alpha are higher in cigarette smokers. Exposure to passive smoking causes a significant increase in 8-epi-PGF2alpha in non-smokers, while in smokers there is only a trendwise increase. After repeated passive smoke exposure, 8-epi-PGF2alpha in non-smokers approaches the respective values of smokers. There is a significant correlation of 8-epi-PGF2alpha to the thromboxane (plasma, serum, conversion from exogenous precursor, 11-dehydro-TXB2) parameters (MDA, HHT- conversion) examined in these patients before. The findings document a significant temporary increase in in vivo oxidation injury due to passive smoke favouring development and/or progression of vascular disease.

The impact of environmental tobacco smoke on women's risk of dying from heart disease: a meta-analysis

OBJECTIVE

To review systematically and analyze the association between environmental tobacco smoke (ETS) exposure and the risk of dying from heart disease in women.

METHODS

We searched the English-language literature using MEDLINE (1966-April 2004), CINAHL, PsychInfo, and bibliographies of selected studies. We included studies that specifically addressed the association of ETS and heart disease mortality in women and had adequate controls and retrievable risk estimates. We looked for either cohort studies or randomized controlled trials. Studies were evaluated independently by two of the authors. Nine cohort studies were finally selected for analysis. We estimated the summary relative risk (RR) and associated 95% confidence intervals (95% CI) using a random-effects model.

RESULTS

Mean follow-up periods for these cohorts ranged from 6 to 39 years. Among non-smoking women, exposure to ETS was associated with a 15% increase in the risk of dying from heart disease compared with nonsmoking women not exposed to ETS (RR = 1.15, 95% CI 1.03-1.28, p < 0.05).

CONCLUSIONS

Among nonsmoking women, exposure to passive smoke increases the risk of dying from heart disease. In accordance with the newly developed guidelines by the American Heart Association for prevention of cardiovascular disease (CVD) in women, we recommend counseling women on reducing or avoiding ETS exposure.

Passive smoking and risk of coronary heart disease and stroke: prospective study with cotinine measurement

OBJECTIVE

To examine the associations between a biomarker of overall passive exposure to tobacco smoke (serum cotinine concentration) and risk of coronary heart disease and stroke.

DESIGN

Prospective population based study in general practice (the British regional heart study).

PARTICIPANTS

4729 men in 18 towns who provided baseline blood samples (for cotinine assay) and a detailed smoking history in 1978-80.

MAIN OUTCOME MEASURE

Major coronary heart disease and stroke events (fatal and non-fatal) during 20 years of follow up.

RESULTS

2105 men who said they did not smoke and who had cotinine concentrations < 14.1 ng/ml were divided into four equal sized groups on the basis of cotinine concentrations. Relative hazards (95% confidence intervals) for coronary heart disease in the second (0.8-1.4 ng/ml), third (1.5-2.7 ng/ml), and fourth (2.8-14.0 ng/ml) quarters of cotinine concentration compared with the first (> or = 0.7 ng/ml) were 1.45 (1.01 to 2.08), 1.49 (1.03 to 2.14), and 1.57 (1.08 to 2.28), respectively, after adjustment for established risk factors for coronary heart disease. Hazard ratios (for cotinine 0.8-14.0 nu > or = 0.7 ng/ml) were particularly increased during the first (3.73, 1.32 to 10.58) and second five year follow up periods (1.95, 1.09 to 3.48) compared with later periods. There was no consistent association between cotinine concentration and risk of stroke.

CONCLUSION

Studies based on reports of smoking in a partner alone seem to underestimate the risks of exposure to passive smoking. Further prospective studies relating biomarkers of passive smoking to risk of coronary heart disease are needed.

Environmental tobacco smoke and myocardial infarction among never-smokers in the Stockholm Heart Epidemiology Program (SHEEP)

An increased risk for myocardial infarction (MI) related to environmental tobacco smoke (ETS) exposure has previously been reported, but several aspects of the association are still uncertain. We studied the MI risk associated with ETS exposure among 334 nonfatal never-smoking MI cases and 677 population controls, 45-70 years of age, in Stockholm County. A postal questionnaire with a telephone follow-up provided information on ETS exposure and other potential risk factors for MI. After adjustment for age, gender, hospital catchment area, body mass index, socioeconomic status, job strain, hypertension, diet, and diabetes mellitus, the odds ratio for MI was 1.58 (95% confidence interval = 0.97-2.56) for an average daily exposure of 20 cigarettes or more from the spouse. Combined exposure from spouse and work showed an increasing odds ratio for MI, up to 1.55 (95% confidence interval = 1.02-2.34) in the highest category of weighted duration, that is, more than 90 "hour-years" of exposure (1 "hour-year" = 365 hours, or 1 hour per day for 1 year). In addition, more recent exposure appeared to convey a higher risk. Our data confirm an increased risk of MI from exposure to ETS and suggest that intensity of spousal exposure, combined exposure from spouse and work, and time since last exposure are important.

Epidemiologic basis for an occupational and environmental policy on environmental tobacco smoke

ETS contains numerous toxins. Robust epidemiologic evidence implicates ETS as a cause of lung cancer and as a primary cause and source of exacerbation of excess respiratory disease. There is also increasing evidence that ETS may be associated with other outcomes, including heart disease. There is currently little doubt that ETS is an important and avoidable health hazard. Unfortunately, ETS is frequently encountered in the workplace--where it is no safer than in other environments and where it presents hazards to exposed workers and to others. A unique aspect of workplace ETS is that exposure is rarely an outcome of essential manufacturing, extraction, or service delivery processes. Moreover, ETS exposure, with its growing list of known hazards, is preventable by engineering or policy means. Implementation of policies to prevent workplace ETS can be highly effective while entailing low costs and yielding primary and secondary benefits to employers and employees. ACOEM strongly supports an increase in the scope and effectiveness of policies and efforts that protect against exposure to ETS in the workplace and elsewhere. To that end, ACOEM supports voluntary, regulatory, and legislative initiatives to eliminate ETS from the workplace, including public spaces such as bars, casinos, restaurants, schools, day-care centers, and public transportation. ACOEM also encourages employers to provide employee training concerning the health hazards of ETS and voluntary personal smoking-cessation programs.

Epidemiologic studies of fatal and nonfatal cardiovascular disease and ETS exposure from spousal smoking

This article reviews the epidemiologic studies of the association of ischemic heart disease risk and environmental tobacco smoke (ETS) exposure from a spouse who smokes. Seventeen studies (nine cohort, eight case-control) comprising more than 485,000 lifelong nonsmokers and 7,345 coronary heart disease (CHD) events were included in a meta-analysis. Together, these studies include 36% more CHD events and 58% more study subjects than were available for review by the U. S. Occupational Safety and Health Administration (OSHA) in 1994. The relative risk (RR) for fatal or nonfatal coronary events among never smokers married to smokers, compared to those whose spouses did not smoke, was RR = 1.25 (95% confidence interval [95% CI], 1.17-1.33) across the combined studies. This association was statistically similar in men (RR = 1.24; 95% CI, 1.15-1.32) and women (RR = 1.23; 95% CI, 1.15-1.32); in studies of cohort (RR = 1.23; 95% CI, 1.15-1. 31) and case-control (RR = 1.47; 95% CI, 1.19-1.81) design; in the United States (RR =1.22; 95% CI, 1.13-1.30) and other countries (RR = 1.41; 95% CI, 1.21-1.65); and in studies of fatal (RR = 1.22; 95% CI, 1.14-1.30) and nonfatal (RR = 1.32; 95% CI, 1.04-1.67) heart disease. In three studies that presented data separately for nonsmokers married to current or former smokers, the association was stronger when the spouses continued to smoke (RR = 1.16, 1.06-1.28) than with former smokers (RR = 0.98; 95% CI, 0.89-1.08). The aggregate data are unlikely to be attributable to chance, publication bias, confounding, or misclassification of exposure. The evidence linking heart disease and ETS exposure from a spouse has become substantially stronger since OSHA first proposed including heart disease in its risk assessment of ETS in 1994.

Passive smoking and the risk of coronary heart disease--a meta-analysis of epidemiologic studies

BACKGROUND

The effect of passive smoking on the risk of coronary heart disease is controversial. We conducted a meta-analysis of the risk of coronary heart disease associated with passive smoking among nonsmokers.

METHODS

We searched the Medline and Dissertation Abstracts Online data bases and reviewed citations in relevant articles to identify 18 epidemiologic (10 cohort and 8 case-control) studies that met prestated inclusion criteria. Information on the designs of the studies, the characteristics of the study subjects, exposure and outcome measures, control for potential confounding factors, and risk estimates was abstracted independently by three investigators using a standardized protocol.

RESULTS

Overall, nonsmokers exposed to environmental smoke had a relative risk of coronary heart disease of 1.25 (95 percent confidence interval, 1.17 to 1.32) as compared with nonsmokers not exposed to smoke. Passive smoking was consistently associated with an increased relative risk of coronary heart disease in cohort studies (relative risk, 1.21; 95 percent confidence interval, 1.14 to 1.30), in case-control studies (relative risk, 1.51; 95 percent confidence interval, 1.26 to 1.81), in men (relative risk, 1.22; 95 percent confidence interval, 1.10 to 1.35), in women (relative risk, 1.24; 95 percent confidence interval, 1.15 to 1.34), and in those exposed to smoking at home (relative risk, 1.17; 95 percent confidence interval, 1.11 to 1.24) or in the workplace (relative risk, 1.11; 95 percent confidence interval, 1.00 to 1.23). A significant dose-response relation was identified, with respective relative risks of 1.23 and 1.31 for nonsmokers who were exposed to the smoke of 1 to 19 cigarettes per day and those who were exposed to the smoke of 20 or more cigarettes per day, as compared with nonsmokers not exposed to smoke (P=0.006 for linear trend).

CONCLUSIONS

Passive smoking is associated with a small increase in the risk of coronary heart disease. Given the high prevalence of cigarette smoking, the public health consequences of passive smoking with regard to coronary heart disease may be important.

Case-control study of passive smoking at home and risk of acute myocardial infarction. Argentine FRICAS Investigators. Factores de Riesgo Coronario en América del Sur

OBJECTIVES

We sought to study the relation between passive smoking at home and the risk of acute myocardial infarction (AMI).

BACKGROUND

Previous epidemiologic studies have linked environmental tobacco smoke to an increased risk of coronary heart disease, but the evidence to support this view is not strong enough. To study this issue further, we analyzed the data from a case-control study conducted in Argentina between 1991 and 1994.

METHODS

Case patients included 336 never-smokers with AMI. Control patients were 446 never-smokers admitted to the same network of hospitals with a wide spectrum of acute disorders unrelated to smoking or to known or suspected risk factors for AMI. Data on the smoking habits of the participants' close relatives (spouse and children) were collected by trained interviewers using a structured questionnaire.

RESULTS

Compared with subjects whose relatives had never smoked, the multivariate odds ratios for passive smokers, according to the smoking status of their relatives, were 1.68 (95% confidence interval [CI] 1.20 to 2.37) for one or more relatives who smoked; 1.59 (95% CI 0.85 to 2.96) for a spouse who smoked; 1.24 (95% CI 0.61 to 2.52) for a spouse who smoked 1 to 20 cigarettes/day; 4.03 (95% CI 0.99 to 16.32) for a spouse who smoked >20 cigarettes/day; and 1.80 (95% CI 1.20 to 2.68) for one or more children who smoked. There was a significant interaction between passive smoking and hypercholesterolemia (> or = 240 mg/dl), hypertension, diabetes and family history of MI.

CONCLUSIONS

In never-smokers, passive smoking at home appeared to be associated with the risk of AMI, and approximately 14% of cases in men and 18% of cases in women in this Argentinian cohort are attributable to passive smoking.

Heart disease from passive smoking in the workplace

OBJECTIVES

This review sought to determine whether passive smoking in the workplace has roughly the same association with heart disease as passive smoking at home and to update a previous 1994 review on the effects of home-based passive exposure on the heart.

BACKGROUND

To predict the effects of passive smoking at work on heart disease, public agencies have had to assume that workplace exposure to tobacco smoke was equivalent to home exposure. With the availability of more workplace exposure data, it is now possible to make a direct comparison.

METHODS

The odds ratios and relative risks (RRs) of the eight studies that contained data on workplace exposure (1,699 cases) were arranged in what was believed to be the order of the quality of their tobacco smoke exposure measurements. A meta-analysis was performed to obtain combined RRs. Data from seven new studies on largely home-based exposure and heart disease that were not included in the 1994 review were also evaluated.

RESULTS

The combined RR for the three top-rated workplace studies was 1.50 (95% confidence interval [CI] 1.12 to 2.01). Adding four lower rated studies reduced the RR to 1.35 (95% CI 1.09 to 1.67). Adding the largest study but the one with questionable exposure history reduced the combined RR to 1.18 (95% CI 1.04 to 1.34). Adding the seven new, largely home-based studies increased the home-based morbidity RR to 1.49 (95% CI 1.29 to 1.72) compared with 1.42 in 1994 while leaving the mortality RR unchanged at 1.23 (95% CI 1.14 to 1.32).

CONCLUSIONS

The RRs for heart disease from passive smoking at work are roughly equal to those from home-based exposure.

Passive smoking and coronary heart disease: a brief review

1. Whether passive smoking or environmental tobacco smoke (ETS) can cause coronary heart disease (CHD) is controversial. We have undertaken a comprehensive review of the epidemiological studies regarding the relationship between ETS and CHD. 2. We searched for all original papers and reviews and calculated pooled odds ratio using the Mantel-Haenszel method. 3. Ten prospective studies, nine case-control studies and one cross-sectional study were found. Almost all studies showed positive associations between ETS and CHD and a few were statistically significant, with dose-response relationships being evident. Six review papers calculated pooled estimates of the relative risks, which ranged from 1.23 to 1.51. Other studies also showed that ETS could have other cardiovascular effects. 4. The association observed is likely to be real. The criteria for causation of time sequence, consistency, coherence and biological plausibility are satisfied. We conclude that ETS may cause CHD, particularly in women who have never smoked.

Dietary and lifestyle correlates of passive smoking in Hong Kong, Japan, Sweden, and the U.S.A

From epidemiologic studies in several countries, passive smoking has been associated with increased risk for lung cancer, respiratory diseases, and coronary heart disease. Since the relative risks derived from those studies are weak, i.e. relative risk less than two, we investigated whether poorer diets and less healthy lifestyles might act as confounders and be correlated with having a smoking husband on a cross-cultural basis. Characteristics of never-smoked wives with or without smoking husbands were compared between 530 women from Hong Kong, 13,047 from Japan, 87 from Sweden, and 144 from the U.S. In all four sites, wives with smoking husbands generally ate less healthy diets. They had a tendency to eat more fried food but less fruit than wives with nonsmoking husbands. Other healthy traits, e.g. avoiding obesity, dietary cholesterol and alcohol, or taking vitamins and participating in preventive screening were also less prevalent among wives with smoking husbands. These patterns suggest that never-smoked wives with smoking husbands tend to share the same less healthy dietary traits characteristic of smokers, and to have dietary habits associated with increased risk for lung cancer and heart disease in their societies. These results emphasize the need to take into account the potential confounding effects of diet and lifestyle in studies evaluating the health effects of passive smoking, especially since it is known that the current prevalence rates of smoking among men is indirectly associated with social class and education in affluent urban societies.

A prospective study of passive smoking and coronary heart disease

BACKGROUND

Several epidemiological studies have suggested an association of passive smoking with coronary heart disease (CHD). However, few studies have taken account of exposure to passive smoking in the workplace. Additionally, several studies have been unable to control for the full range of potential confounding factors. We examined prospectively the relationship of passive smoking with risk of CHD in a cohort of women.

METHODS AND RESULTS

The study was carried out in an ongoing prospective cohort of US female nurses, in whom we assessed exposure to passive smoking at home and at work as well as duration of years spent living with someone who smoked regularly. We studied 32046 women 36 to 61 years of age in 1982 who had never smoked and were free of diagnosed CHD, stroke, and cancer. During 10 years of follow-up (1982 to 1992), 152 incident cases of CHD (127 nonfatal myocardial infarction and 25 fatal CHD) occurred. Compared with women not exposed to passive smoking, the relative risks of total CHD-adjusted for a broad range of cardiovascular risk factors-were 1.58 (95% CI, 0.93 to 2.68) among those reporting occasional exposure and 1.91 (95% CI, 1.11 to 3.28) among women reporting regular exposure to passive smoking at home or work. There was no relation apparent between duration of living with a smoker and risk of CHD.

CONCLUSIONS

Despite the fact that exposure to passive smoking was assessed by self-report and only at baseline (as well as other limitations), these data suggest that regular exposure to passive smoking at home or work increases the risk of CHD among nonsmoking women.

Testosterone worsens endothelial dysfunction associated with hypercholesterolemia and environmental tobacco smoke exposure in male rabbit aorta

OBJECTIVES

To assess the effects of interaction of sex hormones, hypercholesterolemia (HC) and environmental tobacco smoke (ETS) exposure on endothelium-dependent relaxation, we examined vascular reactivity in vitro in an animal model of atherogenesis.

BACKGROUND

Animal and human studies indicate the presence of interactions between classic coronary artery disease risk factors and endothelium-dependent relaxation. Sex hormones have also been shown to influence release of endothelium-derived relaxing factor.

METHODS

New Zealand White rabbits were randomized to receive either an HC diet (n = 8) or ETS exposure plus HC diet (n = 8). Eight rabbits receiving a normal diet, without exposure to ETS, served as the control group. The HC diet consisted of 3% soybean oil and 0.3% cholesterol by weight over 13 weeks. The source of ETS was sidestream smoke of 4 cigarettes/15 min, 6 h/day, 5 days/week over 10 weeks in a smoking chamber. Rabbits were killed, and fresh aortic rings were harvested and maintained in oxygenated Krebs solution in an organ bath at 37 degrees C. Rings were precontracted with norepinephrine and exposed to acetylcholine in increasing doses, and isometric tension was recorded. Rings were also exposed to physiologic concentrations (1 nmol/liter) of either 17-beta-estradiol, testosterone or progesterone before pre-contraction with norepinephrine and relaxation with acetylcholine. Endothelium-independent relaxation was studied using nitroglycerin. The surface area of the ring covered by lipids was measured by Sudan IV staining.

RESULTS

HC and ETS significantly reduced endothelium-dependent relaxation (p = 0.01 and p < 0.0005, respectively) and caused atherogenesis (p < 0.0005 and p = 0.047, respectively) but did not affect endothelium-independent relaxation. Incubation with estradiol and estradiol plus progesterone did not influence endothelium-dependent relaxation. Testosterone reduced endothelium-dependent relaxation (p = 0.049) and augmented the endothelial dysfunction associated with ETS exposure and HC (p = 0.03).

CONCLUSIONS

Both HC and ETS are atherogenic and impair endothelial function but do not affect endothelium-independent relaxation. Physiologic levels of estradiol and estradiol plus progesterone do not affect endothelium-dependent relaxation. Physiologic levels of testosterone impair relaxation and augment the endothelial dysfunction associated with ETS exposure and HC.

Environmental tobacco smoke and coronary heart disease in the American Cancer Society CPS-II cohort

BACKGROUND

Thirteen of 14 epidemiological studies have shown an increased risk of approximately 20% for coronary heart disease (CHD) for never-smokers exposed to environmental tobacco smoke (ETS), but this association remains controversial. If true, ETS might account for an estimated 35,000 to 40,000 heart disease deaths per year in the United States.

METHODS AND RESULTS

We have conducted the largest study to date, a prospective study of 353,180 female and 126,500 male never-smokers enrolled in 1982 in the American Cancer Society's Cancer Prevention Study II and followed through 1989. Analyses focused on subcohorts of 309,599 married pairs and of 135,237 subjects concordant for self-reported exposure and exposure reported by each one's spouse. More than 2800 CHD deaths (ICD 410-414) occurred among married pairs; 10% of married men and 28% of married women were married to currently smoking spouses, while 10% and 32%, respectively, were married to former smokers. After controlling for many cardiovascular risk factors, we found 22% higher CHD mortality (rate ratio, 1.22; 95% CI, 1.07 to 1.40) among never-smoking men married to currently smoking wives compared with those married to wives who had never smoked. The corresponding rate ratio for women was 1.10 (0.96 to 1.27). Never-smokers living with former smokers showed no increased risk. When analyses were restricted to subjects whose ETS exposure was classified via both their own self-report and a spouse's report, the rate ratio was 1.23 (1.03 to 1.47) for currently exposed men and 1.19 (0.97 to 1.45) for women.

CONCLUSIONS

Results are consistent with prior reports that never-smokers currently exposed to ETS have about 20% higher CHD death rates. However, our data do not show consistent dose-response trends and are possibly subject to confounding by unmeasured risk factors.

Passive smoking as a cause of heart disease

The effects of passive smoking on ischemic heart disease are reviewed. Short-term exposures of 20 min to 8 h result in increased platelet sensitivity and decreased ability of the heart to receive and process oxygen. Longer term exposure results in plaque buildup and adverse effects on blood cholesterol. The available epidemiology is reviewed, and it is concluded that passive smoking increases the coronary death rate among U.S. never smokers by 20% to 70%. The newest Environmental Protection Agency procedures for estimating deaths from passive smoking, when applied to the epidemiologic results on heart disease and passive smoking, indicate that in 1985 an estimated 62,000 ischemic heart disease deaths in the United States were associated with exposure to environmental tobacco smoke. Clinicians are advised to counsel their patients to avoid tobacco smoke at home, at work and in transportation settings.

Environmental tobacco smoke exposure among Hispanic women of reproductive age

Exposure to environmental tobacco smoke is a potential health risk for women of reproductive age and their children. Household and workplace exposures were estimated for 4256 Hispanic women age 12 to 49 who participated in the Hispanic health and nutrition examination survey. Age-specific household exposure for nonsmokers was 31% to 62% for Mexican-Americans, 22% to 59% for Puerto Ricans, and 40% to 53% for Cuban-Americans. Exposure was significantly high for Puerto Rican and Mexican-American adolescents, 59% and 62%, respectively. Workplace exposure for nonsmokers was 22% to 35% for Mexican-Americans, 28% to 33% for Puerto Ricans, and 33% to 49% for Cuban-Americans. Young Mexican-American and Puerto Rican and all Cuban-American women reported high exposure to environmental tobacco smoke in the home or workplace. Assessment of family living and smoking patterns, understanding cultural values and norms, and household smoking control and cessation strategies that are mutually derived are useful for nurses and Hispanic and Latino populations to meet the environmental tobacco smoke health objectives for the nation.

[The tobacco habit of the population of the province of Granada]

The aims of this study are to reveal the prevalence of smoking habit amongst the residents in the Granada province and to study some components of the general attitude towards the tobacco habit. The study was a cross-sectional design which is the result of a survey based on a sample of 1537 subjects (all of them being 16 years or over and residents in this province). The participants were chosen by stratified sampling which was realized in two stages: the units of the first stage were censual sections and the second ones were usual family houses. The percentage of smokers was 51.8% male and 17.5% female. The ex-smokers' prevalence was 11.1% (19.0% and men and 3.4% women). 32.5% smokers and 75.0% ex-smokers identified tobacco as a health problem. 45% of smokers had attempted to drop tobacco one or more times. The most frequent motive being the diagnosis of disease or the smoking-related symptoms. This study has revealed the high prevalence of the smoking habit in the province of Granada.

Smoking control in restaurants: the effectiveness of self-regulation in Australia

OBJECTIVES

The provision of smoke-free areas in restaurants has been a controversial issue; the restaurant industry largely opts for a self-regulation approach. This study aimed to examine the effectiveness of self-regulation as a strategy in meeting the industry's and customers' perceived needs.

METHODS

Restaurateur and customer perspectives on the provision of smoke-free areas in restaurants were examined by survey among 365 restaurateurs and 1327 customers in New South Wales, Australia.

RESULTS

Less than 2% of restaurants were totally smoke-free; 22% provided some smoke-free areas. Customers were much more likely than owners to think that smoke-free areas should be provided. Owners appeared to be unaware of customers' views about smoke-free areas in restaurants.

CONCLUSIONS

Little evidence was found to support the effectiveness of the self-regulation policy adopted by the restaurant industry. Characteristics of restaurants and owners associated with the provision of smoke-free areas are presented and implications of the findings are discussed.

Exposure of rats to low concentration of cigarette smoke increases myocardial sensitivity to ischaemia/reperfusion

It is suggested that passive smoking or smoke-exposure increase the risk of coronary heart disease. The same mechanisms as active smoking might play a role. The aim of this study was to determine whether exposure to smoke aggravated ischaemia/reperfusion injury. As a parameter of cellular function and integrity mitochondrial oxidative function was measured. Low molecular weight iron (LMWI) and alpha-tocopherol levels were determined to assess the possibility of toxic hydroxyl radical involvement in myocardial ischaemia/reperfusion injury of smoke-exposed rats. Rats were exposed to a small concentration of cigarette smoke for 2 months (the carboxyhemoglobin concentration did not increase), whereafter hearts were isolated and subjected to ischaemia and ischaemia followed by reperfusion. Mitochondrial oxidative function, low molecular weight iron and alpha-tocopherol were determined. The impairment in mitochondrial oxidative function, LMWI content elevation and the decrease in alpha-tocopherol concentration during ischaemia/reperfusion were significantly more severe in hearts of smoke-exposed rats than non-smokers. These results suggest that exposure to smoke increased the sensitivity of hearts to ischaemia/reperfusion injury, and that a free radical mechanism might participate.

Environmental tobacco smoke: current assessment and future directions

Scientific information on environmental tobacco smoke (ETS) is critically reviewed. Key areas addressed are: differences in chemical composition between mainstream smoke, sidestream smoke, and ETS; techniques for measurement of ETS; epidemiology; in vitro and in vivo toxicology; and chamber and field studies of perceptual or physiological effects. Questions concerning estimation of ETS exposure, suitability of various biomarkers, calculation of lifetime dose, control of confounding variables, use of meta-analysis, and the relationship between ETS concentrations and human responses all emphasize the need for additional research in order to assess potential effects of ETS on health or comfort.

Antioxidant vitamin supplementation of smoke-exposed rats partially protects against myocardial ischaemic/reperfusion injury

Our previous studies showed that exposure of rats to limited periods of cigarette smoke resulted in more severe myocardial damage when their hearts were subjected to myocardial ischaemia/reperfusion. The aim of this study was to determine whether supplementation of rats with antioxidant vitamins alpha-tocopherol and beta-carotene was able to protect their hearts against the increase in ischaemia/reperfusion injury caused by smoke-exposure. The parameters measured were mitochondrial oxidative function, cellular levels of alpha-tocopherol and low molecular weight iron (LMWI). Supplementation with antioxidant vitamins resulted in significantly less mitochondrial functional oxidative damage compared to that observed in the controls. Supplementation did not affect the cellular LMWI content, suggesting that the generation rate of hydroxyl radicals was similar in both groups. The protective effect of alpha-tocopherol and beta-carotene supplementation on the mitochondrial function against ischaemia/reperfusion could be due to their free radical scavenging action. Supplementation with antioxidant vitamins, therefore, had a beneficial effect on the excessive myocardial ischaemia/reperfusion injury of smoke exposed rats.

Passive smoking and heart disease. Epidemiology, physiology, and biochemistry

The evidence that ETS increases risk of death from heart disease is similar to that which existed in 1986 when the US Surgeon General concluded that ETS caused lung cancer in healthy nonsmokers. There are 10 epidemiological studies, conducted in a variety of locations, that reflect about a 30% increase in risk of death from ischemic heart disease or myocardial infarction among nonsmokers living with smokers. The larger studies also demonstrate a significant dose-response effect, with greater exposure to ETS associated with greater risk of death from heart disease. These epidemiological studies are complemented by a variety of physiological and biochemical data that show that ETS adversely affects platelet function and damages arterial endothelium in a way that increases the risk of heart disease. Moreover, ETS, in realistic exposures, also exerts significant adverse effects on exercise capability of both healthy people and those with heart disease by reducing the body's ability to deliver and utilize oxygen. In animal experiments, ETS also depresses cellular respiration at the level of mitochondria. The polycyclic aromatic hydrocarbons in ETS also accelerate, and may initiate, the development of atherosclerotic plaque. Of note, the cardiovascular effects of ETS appear to be different in nonsmokers and smokers. Nonsmokers appear to be more sensitive to ETS than do smokers, perhaps because some of the affected physiological systems are sensitive to low doses of the compounds in ETS, then saturate, and also perhaps because of physiological adaptions smokers undergo as a result of long-term exposure to the toxins in cigarette smoke. In any event, these findings indicate that, for cardiovascular disease, it is incorrect to compute "cigarette equivalents" for passive exposure to ETS and then to extrapolate the effects of this exposure on nonsmokers from the effects of direct smoking on smokers. These results suggest that heart disease is an important consequence of exposure to ETS. The combination of epidemiological studies with demonstration of physiological changes with exposure to ETS, together with biochemical evidence that elements of ETS have significant adverse effects on the cardiovascular system, leads to the conclusion that ETS causes heart disease. This increase in risk translates into about 10 times as many deaths from ETS-induced heart disease as lung cancer; these deaths contribute greatly to the estimated 53,000 deaths annually from passive smoking. This toll makes passive smoking the third leading preventable cause of death in the United States today, behind active smoking and alcohol.