How acute and reversible are the cardiovascular risks of secondhand smoke?

Is secondhand smoke associated with mental health issues? A narrative review of the evidence and policy implications

Secondhand smoke (SHS) is a well-established cause of lung cancer, respiratory disease, heart disease and developmental issues in children, with an overwhelming evidence base spanning over four decades. In this narrative review, we describe studies which have also linked self-reported or cotinine-assessed SHS exposure in the home, workplace and other settings to mental health disorders including depression, suicide, anxiety, and psychological distress in children and adults, sleeping disorders, Attention Deficit Hyperactivity Disorder and behavioural issues in children, and dementia in older adults. In general, evidence indicates that SHS exposure is associated with these disorders in a dose-response manner, with higher odds reported in people who are exposed to SHS at high levels, frequently, and in the home environment. Most studies so far are cross-sectional albeit in large, nationally representative samples from various countries with a smaller number of longitudinal studies. More research is needed in this area to determine whether SHS is a direct cause of adverse mental health outcomes, and whether creating smokefree environments leads to improved mental wellbeing. In particular, more research is needed on the impact of smokefree home environments, an area which has received relatively little focus in smokefree interventions which generally target public places.

Evaluation of Population-Level Tobacco Control Interventions and Health Outcomes: A Systematic Review and Meta-Analysis

Importance

Smoking causes considerable noncommunicable diseases, perinatal morbidity, and mortality.

Objective

To investigate the associations of population-level tobacco-control policies with health outcomes.

Data Sources

PubMed, EMBASE, Web of Science, Cumulated Index to Nursing and Allied Health Literature, and EconLit were searched from inception to March 2021 (updated on 1 March 2022). References were manually searched.

Study Selection

Studies reporting on associations of population-level tobacco control policies with health-related outcomes were included. Data were analyzed from May to July 2022.

Data Extraction and Synthesis

Data were extracted by 1 investigator and cross-checked by a second investigator. Analyses were conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline.

Main Outcomes and Measures

The primary outcomes were respiratory system disease (RSD), cardiovascular disease (CVD), cancer, mortality, hospitalization, and health care utilization. The secondary outcomes were adverse birth outcomes, such as low birth weight and preterm birth. Random-effects meta-analysis was used to estimate pooled odds ratios (ORs) and 95% CIs.

Results

Of 4952 records identified, 144 population-level studies were included in the final analysis; 126 studies (87.5%) were of high or moderate quality. The most frequently reported policies were smoke-free legislation (126 studies), followed by tax or price increases (14 studies), multicomponent tobacco control programs (12 studies), and a minimum cigarette purchase age law (1 study). Smoke-free legislation was associated with decreased risk of all CVD events (OR, 0.90; 95% CI, 0.86-0.94), RSD events (OR, 0.83; 95% CI, 0.72-0.96), hospitalization due to CVD or RSD (OR, 0.91; 95% CI, 0.87-0.95), and adverse birth outcomes (OR, 0.94; 95% CI, 0.92-0.96). These associations persisted in all sensitivity and subgroup analyses, except for the country income category, for which a significant reduction was only observed in high-income countries. In meta-analysis, there was no clear association of tax or price increases with adverse health outcomes. However, for the narrative synthesis, all 8 studies reported statistically significant associations between tax increases and decreases in adverse health events.

Conclusions and Relevance

In this systematic review and meta-analysis, smoke-free legislation was associated with significant reductions in morbidity and mortality related to CVD, RSD, and perinatal outcomes. These findings support the need to accelerate the implementation of smoke-free laws to protect populations against smoking-related harm.

Nicotine dependence of cigarette and heated tobacco users in Japan, 2019: a cross-sectional analysis of the JASTIS Study

OBJECTIVES

Japan is currently the biggest market of heated tobacco products (HTPs) in the world. Little is known about nicotine dependence among HTP users. Thus, the objective was to assess the association of type of tobacco use and time-to-first-use, a marker of nicotine dependence.

METHODS

A cross-sectional analysis of the 2019 data from an internet cohort study was conducted. The analytical sample consisted of 2147 current (≥1 day use in the past 30 days) HTP and/or conventional cigarette users, aged 25+ years. Marginal structural binomial regression was used to estimate nicotine dependence prevalence ratios (PRs) for each category of tobacco use (exclusive daily cigarette, exclusive HTP (≥1 day), dual HTP+daily cigarette, dual HTP+non-daily cigarette), relative to exclusive, non-daily cigarette smoking.

RESULTS

Using a 5 min cut-off for time-to-first-use, the prevalence of nicotine dependence was higher among dual users of HTP and daily cigarettes (PR=1.38; 95% CI: 1.05 to 1.82) and exclusive, daily cigarette users (PR=1.48; 95% CI: 1.15 to 1.91), relative to exclusive, non-daily cigarette users. However, nicotine dependence among exclusive HTP users, and dual HTP+non-daily cigarette users, did not differ from that of exclusive, non-daily cigarette users. When using 15 and 30 min cut-offs, all types of users, including exclusive HTP, had higher levels of nicotine dependence relative to exclusive, non-daily cigarette users.

CONCLUSIONS

Regardless of HTP use, daily cigarette users had higher prevalence of nicotine dependence compared with non-daily cigarette users. Exclusive HTP users had similar (or potentially higher) dependence compared with exclusive, non-daily cigarette users. Longitudinal studies are needed to interrogate the public health implications of growing HTP use worldwide.

Residential secondhand smoke in a densely populated urban setting: a qualitative exploration of psychosocial impacts, views and experiences

Background

People remain exposed to secondhand smoke, a serious health hazard, inside their home as households face challenges in setting no-smoking rules or are exposed to secondhand smoke drifting in from neighbouring homes. This study explores the psychosocial impacts, views, and experiences with residential secondhand smoke in a densely populated urban setting. 

Methods

In-depth online or face to face interviews with 18 key informants who had been involved in public discourse, policy, advocacy or handling complaints related to residential secondhand smoke, 14 smokers, and 16 non-smokers exposed to secondhand smoke inside their home. All participants were residents of Singapore, a densely populated, multi-ethnic city-state. Interview transcripts were coded in NVivo using a deductive and inductive coding process.

Findings

Secondhand smoke has wide-reaching impacts on physical and psychosocial wellbeing, even if smokers tried to minimise secondhand smoke. Feelings of anxiety and stress are generally tied to feeling discomfort in one’s personal space, a perceived lack of control over the situation, resentment towards smokers, and concerns over the health effects. Family, community, and cultural dynamics add complexities to tackling the issue, especially in patriarchal households. Secondhand smoke exposure from neighbours is considered a widespread issue, exacerbated by structural factors such as building layout and the COVID-19 pandemic. Resolving the issue amicably is considered challenging due to the absence of regulations and a reluctance to stir up conflict with neighbours. While smokers took measures to reduce secondhand smoke, these were described as ineffective by other participants. Smokers appeared to have contrasting views from other participants on what it means to smoke in a socially responsible manner.

Conclusion

Given the wide-reaching psychosocial impacts of residential secondhand smoke, there is a case for stronger interventions, especially in densely populated urban settings where it is more difficult to avoid.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13561-7.

Secondhand smoke in the densely populated urban setting: A cross-sectional survey of exposure, knowledge, attitudes, and respiratory symptoms

Secondhand smoke (SHS) remains a common health threat in densely populated, urban settings. We estimated the prevalence of exposure and associated respiratory symptoms, knowledge, attitudes, and behaviors in a multi-ethnic, weighted sample of Singapore residents using a cross-sectional survey of 1806 adults. We weighted data to match the national population in terms of gender, ethnicity, and education level and analyzed data using descriptive statistics, bivariate analyses, multiple linear and logistic regressions, and a multinomial logistic regression model. About 88% of respondents reported regular SHS exposure. Nearly 57% reported exposure to neighbors' SHS at home. Respiratory symptoms were reported by 32.5% and significantly associated with exposure to daily (AOR = 2.63, 95% CI = 1.62-4.36), non-daily (AOR = 1.75, 95% CI = 1.14-2.77), and neighbors' (AOR = 1.37, 95% CI = 1.07-1.76) SHS. More knowledge of SHS was associated with male gender (β = 0.28, p = 0.0009) and higher household income (linear trend; p = 0.0400). More negative attitudes to SHS were associated with older age (linear trend; p < 0.0001). Engaging in behaviors to avoid SHS was associated with a more negative attitude to SHS (AOR = 1.09-1.23). SHS exposure is common in Singapore's densely populated setting and associated with respiratory symptoms, even if exposure is non-daily or from neighboring homes.

Smoke-Free Policies and 30-Day Readmission Rates for Chronic Obstructive Pulmonary Disease

INTRODUCTION

Previous evidence has shown that smoke-free policies reduce hospital admissions due to respiratory causes, but the impact on 30-day readmission has not been determined. As 25 states in the U.S. have not adopted comprehensive smoke-free legislation, it is likely that patients return to an environment that increases risk of a secondary event. The aim of this study is to investigate the impact of smoke-free policies on 30-day readmission rates for adults aged ≥65 years following hospitalization for chronic obstructive pulmonary disease in the U.S.

METHODS

Data from the U.S. Tobacco Control Laws Database, Centers for Medicare and Medicaid Services Hospital Readmissions Reduction Program, American Hospital Association, Area Health Resource File, and U.S. Census Bureau Current Population Survey were merged at the county level for years 2013-2016 and analyzed in 2018. Hierarchical Poisson regression models were utilized to calculate incidence rate ratios to determine the impact of full, partial, and no smoke-free policies on 30-day readmission rates after chronic obstructive pulmonary disease hospitalization.

RESULTS

Multivariable analysis adjusting for both county and hospital characteristics revealed that the presence of full (incidence rate ratio=0.81, 95% CI=0.76, 0.88) and partial (incidence rate ratio=0.87, 95% CI=0.81, 0.92) smoke-free policies were associated with fewer 30-day readmissions for chronic obstructive pulmonary disease-related hospitalizations when compared with counties with no smoke-free policy.

CONCLUSIONS

The implementation of smoke-free policies is an effective measure for reducing 30-day readmissions following hospitalization due to chronic obstructive pulmonary disease, with stronger policies resulting in decreased risk. Efforts to reduce chronic obstructive pulmonary disease-related 30-day readmissions should include the implementation of smoke-free policies.

Low cigarette consumption and risk of coronary heart disease and stroke: meta-analysis of 141 cohort studies in 55 study reports

OBJECTIVE

To use the relation between cigarette consumption and cardiovascular disease to quantify the risk of coronary heart disease and stroke for light smoking (one to five cigarettes/day).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline 1946 to May 2015, with manual searches of references.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Prospective cohort studies with at least 50 events, reporting hazard ratios or relative risks (both hereafter referred to as relative risk) compared with never smokers or age specific incidence in relation to risk of coronary heart disease or stroke.

DATA EXTRACTION/SYNTHESIS

MOOSE guidelines were followed. For each study, the relative risk was estimated for smoking one, five, or 20 cigarettes per day by using regression modelling between risk and cigarette consumption. Relative risks were adjusted for at least age and often additional confounders. The main measure was the excess relative risk for smoking one cigarette per day (RR1_per_day-1) expressed as a proportion of that for smoking 20 cigarettes per day (RR20_per_day-1), expected to be about 5% assuming a linear relation between risk and consumption (as seen with lung cancer). The relative risks for one, five, and 20 cigarettes per day were also pooled across all studies in a random effects meta-analysis. Separate analyses were done for each combination of sex and disorder.

RESULTS

The meta-analysis included 55 publications containing 141 cohort studies. Among men, the pooled relative risk for coronary heart disease was 1.48 for smoking one cigarette per day and 2.04 for 20 cigarettes per day, using all studies, but 1.74 and 2.27 among studies in which the relative risk had been adjusted for multiple confounders. Among women, the pooled relative risks were 1.57 and 2.84 for one and 20 cigarettes per day (or 2.19 and 3.95 using relative risks adjusted for multiple factors). Men who smoked one cigarette per day had 46% of the excess relative risk for smoking 20 cigarettes per day (53% using relative risks adjusted for multiple factors), and women had 31% of the excess risk (38% using relative risks adjusted for multiple factors). For stroke, the pooled relative risks for men were 1.25 and 1.64 for smoking one or 20 cigarettes per day (1.30 and 1.56 using relative risks adjusted for multiple factors). In women, the pooled relative risks were 1.31 and 2.16 for smoking one or 20 cigarettes per day (1.46 and 2.42 using relative risks adjusted for multiple factors). The excess risk for stroke associated with one cigarette per day (in relation to 20 cigarettes per day) was 41% for men and 34% for women (or 64% and 36% using relative risks adjusted for multiple factors). Relative risks were generally higher among women than men.

CONCLUSIONS

Smoking only about one cigarette per day carries a risk of developing coronary heart disease and stroke much greater than expected: around half that for people who smoke 20 per day. No safe level of smoking exists for cardiovascular disease. Smokers should aim to quit instead of cutting down to significantly reduce their risk of these two common major disorders.

Decrease in mortality rate and hospital admissions for acute myocardial infarction after the enactment of the smoking ban law in São Paulo city, Brazil

BACKGROUND

Smoking restriction laws have spread worldwide during the last decade. Previous studies have shown a decline in the community rates of myocardial infarction after enactment of these laws. However, data are scarce about the Latin American population. In the first phase of this study, we reported the successful implementation of the law in São Paulo city, with a decrease in carbon monoxide rates in hospitality venues.

OBJECTIVE

To evaluate whether the 2009 implementation of a comprehensive smoking ban law in São Paulo city was associated with a reduction in rates of mortality and hospital admissions for myocardial infarction.

METHODS

We performed a time-series study of monthly rates of mortality and hospital admissions for acute myocardial infarction from January 2005 to December 2010. The data were derived from DATASUS, the primary public health information system available in Brazil and from Mortality Information System (SIM). Adjustments and analyses were performed using the Autoregressive Integrated Moving Average with exogenous variables (ARIMAX) method modelled by environmental variables and atmospheric pollutants to evaluate the effect of smoking ban law in mortality and hospital admission rate. We also used Interrupted Time Series Analysis (ITSA) to make a comparison between the period pre and post smoking ban law.

RESULTS

We observed a reduction in mortality rate (-11.9% in the first 17 months after the law) and in hospital admission rate (-5.4% in the first 3 months after the law) for myocardial infarction after the implementation of the smoking ban law.

CONCLUSIONS

Hospital admissions and mortality rate for myocardial infarction were reduced in the first months after the comprehensive smoking ban law was implemented.

Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Cardiovascular Events Following Smoke-Free Legislations: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Legislations banning smoking in indoor public places and workplaces are being implemented worldwide to protect the population from secondhand smoke exposure. Several studies have reported reductions in hospitalizations for acute coronary events following the enactment of smoke-free laws.

OBJECTIVE

We set out to conduct a systematic review and meta-analysis of epidemiologic studies examining how legislations that ban smoking in indoor public places impact the risk of acute coronary events.

METHODS

We searched MEDLINE, EMBASE, and relevant bibliographies including previous systematic reviews for studies that evaluated changes in acute coronary events, following implementation of smoke-free legislations. Studies were identified through December 2013. We pooled relative risk (RR) estimates for acute coronary events comparing post- vs. pre-legislation using inverse-variance weighted random-effects models.

RESULTS

Thirty-one studies providing estimates for 47 locations were included. The legislations were implemented between 1991 and 2010. Following the enactment of smoke-free legislations, there was a 12 % reduction in hospitalizations for acute coronary events (pooled RR: 0.88, 95 % CI: 0.85-0.90). Reductions were 14 % in locations that implemented comprehensive legislations compared to an 8 % reduction in locations that only had partial restrictions. In locations with reductions in smoking prevalence post-legislation above the mean (2.1 % reduction) there was a 14 % reduction in events compared to 10 % in locations below the mean. The RRs for acute coronary events associated with enacting smoke-free legislation were 0.87 vs. 0.89 in locations with smoking prevalence pre-legislation above and below the mean (23.1 %), and 0.87 vs. 0.89 in studies from the Americas vs. other regions.

CONCLUSION

The implementation of smoke-free legislations was related to reductions in acute coronary event hospitalizations in most populations evaluated. Benefits are greater in locations with comprehensive legislations and with greater reduction in smoking prevalence post-legislation. These cardiovascular benefits reinforce the urgent need to enact and enforce smoke-free legislations that protect all citizens around the world from exposure to tobacco smoke in public places.

Reduction of ST-elevation myocardial infarction in Canton Ticino (Switzerland) after smoking bans in enclosed public places--No Smoke Pub Study

BACKGROUND

Second-hand smoke increases the risk of acute myocardial infarction. Canton Ticino (CT) first introduced a smoking ban in public places in 2007. This offered the opportunity to assess the long-term impact of a smoking ban on the incidence of ST-elevation myocardial infarctions (STEMI) compared with a population where the law was not yet implemented.

METHODS

We assessed the incidence of STEMI hospitalizations per 100 000 inhabitants both during 3 years before and after the ban application in CT and in Canton Basel City (CBC), where this law was not yet applied. Data were obtained from the codified hospital registry (ICD-10 codes).

RESULTS

In CT, the mean incidence of STEMI admissions during the 3 pre-ban years (123.7) was significantly higher than the incidence of admissions in each of the 3 post-ban years (92.9, 101.6 and 89.6 respectively; P <.024). Analysing population subsets, a post-ban reduction was observed among ≥65-year-old people of both sexes in each of the 3 post-ban years and in the <65-year age group during the first post-ban year (P = 0.02). Conversely, the mean incidence of STEMI hospitalizations in CBC (92.4) didn't change significantly in each of the 3 post-ban years (83.9, 83.3 and 79.5, P = NS) during the same period. However, a significant long-term reduction in STEMI admissions was observed in CBC among the male group with ≥65 years (P < 0.01).

CONCLUSION

Our work suggests a significant impact of the smoke-free policy on the number of annual STEMI. Specific population subsets (i.e. ≥65-year-old females) were particularly affected by the smoking ban, showing a significant reduction in STEMI hospitalizations.

Controlled experiments measuring personal exposure to PM2.5 in close proximity to cigarette smoking

Few measurements of exposure to secondhand smoke (SHS) in close proximity to a smoker are available. Recent health studies have demonstrated an association between acute (<2 h) exposures to high concentrations of SHS and increased risk of cardiovascular and respiratory disease. We performed 15 experiments inside naturally ventilated homes and 16 in outdoor locations, each with 2-4 non-smokers sitting near a cigarette smoker. The smoker's and non-smokers' real-time exposures to PM2.5 from SHS were measured by using TSI SidePak monitors to sample their breathing zones. In 87% of the residential indoor experiments, the smoker received the highest average exposure to SHS, with PM2.5 concentrations ranging from 50-630 μg/m(3) . During the active smoking period, individual non-smokers sitting within approximately 1 m of a smoker had average SHS exposures ranging from negligible up to >160 μg/m(3) of PM2.5 . The average incremental exposure of the non-smokers was higher indoors (42 μg/m(3) , n = 35) than outdoors (29 μg/m(3) , n = 47), but the overall indoor and outdoor frequency distributions were similar. The 10-s PM2.5 averages during the smoking periods showed great variability, with multiple high concentrations of short duration (microplumes) both indoors and outdoors.

The association of tobacco control policies and the risk of acute myocardial infarction using hospital admissions data

Objective

To evaluate the association of a nationwide comprehensive smoking ban (CSB) and tobacco tax increase (TTI) on the risk of acute myocardial infarctions (AMI) in Panama for the period of 2006 – 2010 using hospital admissions data.

Methods

Data of AMI cases was gathered from public and private hospitals in the country for the period of January 1, 2006 to December 31, 2010. The number of AMI cases was calculated on a monthly basis. The risk of AMI was estimated for the pre-CSB period (January 2006 to April 2008) and was used as a reference point. Three post-intervention periods were examined: (1) post-CSB from May 2008 to April 2009 (12 months); (2) post-CSB from May 2009 to November 2009 (7 months); and (3) post-TTI from December 2009 to December 2010 (13 months). Relative risks (RR) of AMI were estimated for each post intervention periods by using a Poisson regression model. Mortality registries for the country attributed to myocardial infarction (MI) were obtained from January 2001 to December 2012. The annual percentage change (APC) of the number of deaths from MI was calculated using Joinpoint regression analysis.

Results

A total sample size of 2191 AMI cases was selected (monthly mean number of cases 36.52±8.24 SD). Using the pre-CSB as a reference point (RR = 1.00), the relative risk of AMI during the first CSB period, the second CSB period and post-TTI were 0.982, 1.049, and 0.985, respectively. The APC of deaths from MI from January 2001 to April 2008 was 0.5%. From January 2001 to June 2010 the APC trend was 0.47% and from July 2010 to December 2012 the APC was –0.3%.

Conclusions

The implementation of a CSB and TTI in Panama were associated with a decrease in tobacco consumption and a reduction of the RR of AMI.

Smoking bans linked to lower hospitalizations for heart attacks and lung disease among medicare beneficiaries

Policies limiting exposure to cigarette smoke have been associated with reduced hospitalizations for heart attacks, but little is known about the impact of smoking bans on other health conditions and whether findings from individual communities generalize to other areas. We investigated the association between smoking bans targeting workplaces, restaurants, and bars passed throughout the United States during 1991-2008 and hospital admissions for smoking-related illnesses-acute myocardial infarction and chronic obstructive pulmonary disease-among Medicare beneficiaries age sixty-five or older. Risk-adjusted hospital admission rates for acute myocardial infarction fell 20-21 percent thirty-six months following implementation of new restaurant, bar, and workplace smoking bans. Admission rates for chronic obstructive pulmonary disease fell 11 percent where workplace smoking bans were in place and 15 percent where bar smoking bans were present. By contrast, very little effect was found for hospitalization for gastrointestinal hemorrhage and hip fracture-two conditions largely unrelated to smoking and examined as points of comparison. These findings provide further support for the public health benefits of laws that limit exposure to tobacco smoke.

Biomarkers of tobacco smoke exposure and asthma severity in adults

BACKGROUND

Tobacco biomarkers including serum cotinine and urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) have been used in research settings.

PURPOSE

The goal of the study was to examine the association of cotinine and NNAL with asthma outcomes in the U.S. adult population.

METHODS

A cross-sectional design was used, using data from the National Health and Nutrition Examination Survey, 2007-2008, with participants aged >20 years with self-reported asthma (N=456). Past-year asthma exacerbations and emergency room/urgent care visits for asthma were examined. Analyses were conducted in 2013.

RESULTS

Among adult asthmatics, 50.3% reported a past-year asthma attack (61.8% smokers, 46.6% nonsmokers, p=0.029). Among these, 24.7% reported a past-year emergency/urgent visit for asthma (34.7% smokers, 20.1% nonsmokers, p=0.034). Median concentrations of cotinine and creatinine-adjusted NNAL (NNAL/Cr) were significantly higher in those with a past-year asthma attack (0.43 ng/mL and 7.28 pg/mL) than in those without (0.06 ng/mL and 2.26 pg/mL), and highest in those with past-year emergency/urgent visits (0.93 ng/mL and 28.14 pg/mL). Among nonsmokers, increasing levels of log cotinine or log NNAL/Cr, adjusted for demographics, were significantly associated with past-year asthma exacerbation (log cotinine OR=1.46 [95% CI=1.1, 1.92]; log NNAL/Cr OR=1.42 [95% CI=1.07, 1.88]) and past-year emergency/urgent visit (log cotinine OR=1.95 [95% CI=1.32, 2.88]; log NNAL/Cr OR=1.58 [95% CI=1.23, 2.02]). Among smokers, increasing biomarker levels were not significantly associated with either outcome.

CONCLUSIONS

In a population-based cross-sectional analysis, increased cotinine and NNAL were found to be associated with asthma exacerbation and healthcare use in nonsmokers with asthma. If these findings are confirmed in prospective studies, these biomarkers might be candidates for clinical indicators of risk of asthma.

The effects of smoke-free legislation on acute myocardial infarction: a systematic review and meta-analysis

Background

Comprehensive smoke-free legislation has been implemented in many countries. The current study quantitatively examined the reduction in risk of acute myocardial infarction (MI) occurrence following the legislations and the relationship with the corresponding smoking prevalence decrease.

Methods

PubMed, EMBASE, and Google Scholar databases and bibliographies of relevant studies and reviews were searched for potential original studies published from January 1, 2004, through October 31, 2011. Meta-analysis was performed using a random effect model to estimate the overall effects of the smoking-free legislations. Meta-regression was used to investigate possible causes of heterogeneity in risk estimates.

Results

A total of 18 eligible studies with 44 estimates of effect size were used in this study. Meta-analysis produced a pooled estimate of the relative risk of 0.87 (95% confidence interval (CI): 0.84 to 0.91). There was significant heterogeneity in the risk estimates (overall I² = 96.03%, p<0.001). In meta-regression analysis, studies with greater smoking prevalence decrease produced larger relative risk (adjusted coefficient −0.027, 95% CI: -0.049 to −0.006, p=0.014).

Conclusion

Smoke-free legislations in public and work places were associated with significant reduction in acute MI risk, which might be partly attributable to reduced smoking prevalence.

Reductions in cardiovascular, cerebrovascular, and respiratory mortality following the national irish smoking ban: interrupted time-series analysis

Background

Previous studies have shown decreases in cardiovascular mortality following the implementation of comprehensive smoking bans. It is not known whether cerebrovascular or respiratory mortality decreases post-ban. On March 29, 2004, the Republic of Ireland became the first country in the world to implement a national workplace smoking ban. The aim of this study was to assess the effect of this policy on all-cause and cause-specific, non-trauma mortality.

Methods

A time-series epidemiologic assessment was conducted, utilizing Poisson regression to examine weekly age and gender-standardized rates for 215,878 non-trauma deaths in the Irish population, ages ≥35 years. The study period was from January 1, 2000, to December 31, 2007, with a post-ban follow-up of 3.75 years. All models were adjusted for time trend, season, influenza, and smoking prevalence.

Results

Following ban implementation, an immediate 13% decrease in all-cause mortality (RR: 0.87; 95% CI: 0.76–0.99), a 26% reduction in ischemic heart disease (IHD) (RR: 0.74; 95% CI: 0.63–0.88), a 32% reduction in stroke (RR: 0.68; 95% CI: 0.54–0.85), and a 38% reduction in chronic obstructive pulmonary disease (COPD) (RR: 0.62; 95% CI: 0.46–0.83) mortality was observed. Post-ban reductions in IHD, stroke, and COPD mortalities were seen in ages ≥65 years, but not in ages 35–64 years. COPD mortality reductions were found only in females (RR: 0.47; 95% CI: 0.32–0.70). Post-ban annual trend reductions were not detected for any smoking-related causes of death. Unadjusted estimates indicate that 3,726 (95% CI: 2,305–4,629) smoking-related deaths were likely prevented post-ban. Mortality decreases were primarily due to reductions in passive smoking.

Conclusions

The national Irish smoking ban was associated with immediate reductions in early mortality. Importantly, post-ban risk differences did not change with a longer follow-up period. This study corroborates previous evidence for cardiovascular causes, and is the first to demonstrate reductions in cerebrovascular and respiratory causes.

Impact of a partial smoke-free legislation on myocardial infarction incidence, mortality and case-fatality in a population-based registry: the REGICOR Study

BACKGROUND AND OBJECTIVE

Coronary heart disease (CHD) is the leading cause of death, and smoking its strongest modifiable risk factor. Our aim was to determine the impact of the Spanish 2006 partial smoke-free legislation on acute myocardial infarction (AMI) incidence, hospitalization and mortality rates, and 28-day case-fatality in Girona, Spain.

METHODS

Using a population-based registry (the REGICOR Study), we compared population incidence, hospitalization, and mortality rates, and 28-day case-fatality in the pre- and post-ban periods (2002-2005 and 2006-2008, respectively) by binomial regression analysis adjusted for confounding factors. We also analyzed the ban's impact on the outcomes of interest using the AMI definitions of the American Heart Association (AHA)/European Society of Cardiology (ESC) and the World Health Organization (WHO)-Monitoring trends and determinants in cardiovascular diseases (MONICA).

RESULTS

In the post-ban period, AMI incidence and mortality rates significantly decreased (relative risk [RR] = 0.89; 95% confidence interval [CI] = 0.81-0.97 and RR = 0.82; 95% CI = 0.71-0.94, respectively). Incidence and mortality rates decreased in both sexes, especially in women, and in people aged 65-74 years. Former and non-smokers (passive smokers) showed diminished incidence rates. Implementation of the ban was not associated with AMI case-fatality. Models tended to be more significant with the WHO-MONICA than with the AHA/ESC definition.

CONCLUSIONS

The 2006 Spanish partial smoke-free legislation was associated with a decrease in population AMI incidence and mortality, particularly in women, in people aged 65-74 years, and in passive smokers. These results clarify the association between AMI mortality and the enactment of a partial smoke-free legislation and reinforce the effectiveness of smoking regulations in preventing CHD.

News Media Outreach and Newspaper Coverage of Tobacco Control

Introduction.

Little is known about the impact of media outreach on news media coverage of tobacco control.

Methods.

Media outreach data were obtained from the Centers for Disease Control and Prevention’s Office on Smoking and Health (CDC/OSH) from 2003 to 2006; one to six types of outreach activities for 50 scientific publications were performed during 35 discrete time periods. The authors analyzed quantitatively and qualitatively 205 newspaper articles generated based on the CDC/OSH scientific publications.

Results.

Media coverage of specific CDC/OSH-related tobacco themes was highest for disparities (100%) and tobacco statistics (98%). More outreach activities increased the likelihood of moderate pickup of the number of themes in newspaper articles (odds ratio = 2.0, 95% confidence interval = 1.5-2.8), but there appeared to be a ceiling effect. Certain types of outreach were more strongly associated with front page and headline coverage.

Conclusions.

The extent and type of outreach were associated with increased newspaper coverage but the relationship is not necessarily straightforward. Additional research is needed to better understand relationships between scientific findings, outreach, and news media coverage of tobacco.

Low-dose nonlinear effects of smoking on coronary heart disease risk

Some recent discussions of adverse human health effects of active and passive smoking have suggested that low levels of exposure are disproportionately dangerous, so that "The effects of even brief (minutes to hours) passive smoking are often nearly as large (averaging 80% to 90%) as chronic active smoking" (Barnoya and Glantz, 2005). Recent epidemiological evidence (Teo et al., 2006) suggests a more linear relation. This paper reexamines the empirical relation between self-reported low levels of active smoking and risk of coronary heart disease (CHD) in public-domain data from the National Health and Nutrition Examination Survey (NHANES). Consistent with biological evidence on J-shaped and U-shaped relations between smoking-associated risk factors and CHD risks, we find that low levels of active smoking do not appear to be associated with increased CHD risk. Several methodological challenges in epidemiology may explain how model-derived estimates can predict low-dose linear or concave dose-response estimates, even if the empirical (i.e., data-based) relation does not show a clear increased risk at the lowest doses.

Primary care providers advising smokers to quit: comparing effectiveness between those with and without alcohol, drug, or mental disorders

INTRODUCTION

Individuals with alcohol, drug, or mental (ADM) disorders combined make up over 40% of all smokers in the U.S. Primary care providers (PCPs) play an important role in smoking cessation counseling, but their effectiveness with this population is unclear. This study evaluated the effectiveness of PCP smoking cessation counseling for smokers with ADM disorders.

METHODS

Probit regressions conducted in 2009-2010 examined the relationship between past year PCP smoking cessation counseling and successful quitting among 1,356 adults who reported smoking in the 1998-1999 Community Tracking Study survey and who reported seeing a PCP in the past year in the follow-up 2000-2001 Healthcare for Communities Survey. Past year PCP exercise counseling was used as an instrumental variable for past year PCP smoking cessation counseling to account for potential hidden bias between smoking status and receipt of smoking cessation counseling.

RESULTS

Smokers with and without ADM disorders were equally likely to receive smoking cessation counseling (72.9% vs. 69.9%). Using the instrumental variable approach, smoking cessation counseling by PCPs was significantly associated (p < .01) with quitting among both groups. Predicted probabilities of quitting without smoking cessation counseling were 6.0% for smokers with ADM disorders and 10.5% for smokers without ADM disorders. Predicted probabilities of quitting with smoking cessation counseling were 31.3% for smokers with ADM disorders and 34.9% for smokers without ADM disorders.

CONCLUSIONS

This study shows that PCPs can help smokers with ADM disorders successfully quit. These smokers should be targeted for smoking cessation counseling to reduce the health burden of tobacco.

Effect of brief secondhand smoke exposure on endothelial function and circulating markers of inflammation

OBJECTIVE

In contrast to the well defined detrimental consequences of long-term secondhand smoke (SHS) exposure, little is known about the acute effects of passive smoking on endothelial function and inflammation. The aim of the present study was to assess the acute effects of short-term SHS exposure on endothelial function and circulating markers of inflammation.

METHODS

Peripheral microvascular endothelial function assessed by reactive hyperemia peripheral arterial tonometry (RH-PAT) index, circulating markers of endothelial function (von Willebrand factor antigen, Thrombomodulin, E-selectin) and circulating inflammatory markers (high sensitivity C-reactive protein (hsCRP), Interleukin-6 (IL-6)) were measured in eighteen male, non-smoking volunteers before and 12h after a 1-h SHS exposure.

RESULTS

Twelve hours after passive smoking, average RH-PAT index was significantly lower than before SHS exposure (1.54±0.49 vs 2.01±0.55 (mean±SD), p=0.01) indicating deterioration of peripheral microvascular endothelial function. von Willebrand factor antigen as a marker of endothelial activation was significantly increased after SHS exposure (93.0±25.5% vs 78.4±17.9%, p=0.03). Levels of Thrombomodulin, E-selectin, hsCRP, and IL-6 were unaffected by SHS exposure.

CONCLUSION

Short-term SHS exposure leads to a measurable disturbance of endothelial function. However, 1h of passive smoking appears to be too short to elicit a significant inflammatory response.

Short term impact of smoke-free legislation in England: retrospective analysis of hospital admissions for myocardial infarction

OBJECTIVE

To measure the short term impact on hospital admissions for myocardial infarction of the introduction of smoke-free legislation in England on 1 July 2007.

DESIGN

An interrupted time series design with routinely collected hospital episode statistics data. Analysis of admissions from July 2002 to September 2008 (providing five years' data from before the legislation and 15 months' data from after) using segmented Poisson regression.

SETTING

England. Population All patients aged 18 or older living in England with an emergency admission coded with a primary diagnosis of myocardial infarction.

MAIN OUTCOME MEASURES

Weekly number of completed hospital admissions.

RESULTS

After adjustment for secular and seasonal trends and variation in population size, there was a small but significant reduction in the number of emergency admissions for myocardial infarction after the implementation of smoke-free legislation (-2.4%, 95% confidence interval -4.06% to -0.66%, P=0.007). This equates to 1200 fewer emergency admissions for myocardial infarction (1600 including readmissions) in the first year after legislation. The reduction in admissions was significant in men (3.1%, P=0.001) and women (3.8%, P=0.007) aged 60 and over, and men (3.5%, P<0.01) but not women (2.5% P=0.38) aged under 60.

CONCLUSION

This study adds to a growing body of evidence that smoke-free legislation leads to reductions in myocardial infarctions. It builds on previous work by showing that such declines are observed even when underlying reductions in admissions and potential confounders are controlled for. The considerably smaller decline in admissions observed in England compared with many other jurisdictions probably reflects aspects of the study design and the relatively low levels of exposure to secondhand smoke in England before the legislation.

Hospital admissions for acute myocardial infarction, angina, stroke, and asthma after implementation of Arizona's comprehensive statewide smoking ban

OBJECTIVES

We examined the impact of Arizona's May 2007 comprehensive statewide smoking ban on hospital admissions for diagnoses for which there is evidence of a causal relationship with secondhand smoke (SHS) exposure (acute myocardial infarction [AMI], angina, stroke, and asthma).

METHODS

We compared monthly hospital admissions from January 2004 through May 2008 for these primary diagnoses and 4 diagnoses not associated with SHS (appendicitis, kidney stones, acute cholecystitis, and ulcers) for Arizona counties with preexisting county or municipal smoking bans and counties with no previous bans. We attributed reductions in admissions to the statewide ban if they occurred only in diagnoses associated with SHS and if they were larger in counties with no previous bans. We analyzed the data with Poisson regressions, controlling for seasonality and admissions trends. We also estimated cost savings.

RESULTS

Statistically significant reductions in hospital admissions were seen for AMI, angina, stroke, and asthma in counties with no previous bans over what was seen in counties with previous bans. No ban variable coefficients were statistically significant for diagnoses not associated with SHS.

CONCLUSIONS

Arizona's statewide smoking ban decreased hospital admissions for AMI, stroke, asthma, and angina.

Changes in the SF-8 scores among healthy non-smoking school teachers after the enforcement of a smoke-free school policy: a comparison by passive smoke status

Background

The effects of the enforcement of a smoke-free workplace policy on health-related quality of life (HRQOL) among a healthy population are poorly understood. The present study was undertaken to examine the effects of the enforcement of a smoke-free school policy on HRQOL among healthy non-smoking schoolteachers with respect to their exposure to passive smoke.

Methods

Two self-reported questionnaire surveys were conducted, the first before and the second after the enforcement of a total smoke-free public school policy in Nara City. A total of 1534 teachers were invited from 62 schools, and their HRQOL was assessed using six domains extracted from the Medical Outcomes Survey Short Form-8 questionnaire (SF-8): general health perception (GH), role functioning-physical (RP), vitality (VT), social functioning (SF), mental health (MH), and role functioning-emotional (RE). The participants were divided into two groups according to their exposure to environmental tobacco smoke (ETS) at baseline: participants not exposed to ETS at school (non-smokers), and participants exposed to ETS at school (passive smokers). Changes in each SF-8 score were evaluated using paired t-tests for each group, and their inter-group differences were evaluated using multiple linear regression analyses adjusted for sex, age, school type, managerial position, and attitude towards a smoke-free policy.

Results

After ineligible subjects were excluded, 689 teachers were included in the analyses. The number of non-smokers and passive smokers was 447 and 242, respectively. Significant changes in SF-8 scores were observed for MH (0.9; 95% confidence interval [CI], 0.2-1.5) and RE (0.7; 95% CI, 0.0-1.3) in non-smokers, and GH (2.2; 95% CI, 1.2-3.1), VT (1.8; 95% CI, 0.9-2.7), SF (2.7; 95% CI, 1.6-3.8), MH (2.0; 95% CI, 1.0-2.9), and RE (2.0; 95% CI, 1.2-2.8) in passive smokers. In the multiple linear regression analyses, the net changes in the category scores of GH (1.8; 95% CI, 0.7-2.9), VT (1.4, 95% CI, 0.3-2.5), SF (2.5; 95% CI, 1.1-3.9), MH (1.2; 95% CI, 0.1-2.4) and RE (1.6; 95% CI, 0.5-2.7) in passive smokers significantly exceeded those in non-smokers.

Conclusions

A smoke-free school policy would improve the HRQOL of healthy non-smoking teachers who are exposed to ETS.

Assessing the effects of the introduction of the New Zealand Smokefree Environment Act 2003 on acute myocardial infarction hospital admissions in Christchurch, New Zealand

OBJECTIVE

To examine trends in Acute Myocardial Infarction (AMI) hospital admissions in Christchurch, New Zealand before and after the implementation of the New Zealand Smokefree Environments Act 2003 in December 2004.

METHODS

Data on AMI hospital admissions to Christchurch Public Hospital were extracted for the period 2003 to 2006. Poisson regression was used to calculate rate ratios by comparing for AMI rates of hospital admissions before (2003/04) and after (2005/06) the introduction of the Smokefree legislation, and to assess whether there was a significant change over time.

RESULTS

The introduction of the smokefree legislation was associated with a 5% reduction in AMI admissions. The 55-74 age group recorded the greatest decrease in admissions (9%) and this figure rose to 13% among never smokers in this group. Reductions were more marked for men. Adding the effects of area deprivation increased the reduction to 21% among 55-74 year olds living in more affluent (quintile 2) areas. Overall however, the statistical association of changing levels of AMI admissions with smoking status and with deprivation was not consistently significant.

CONCLUSION

At this early stage following the smokefree legislation, there are hints emerging of a positive impact on AMI admissions but these suggestions cannot yet be treated with certainty. Further research could usefully evaluate the longer-term effects of smoking legislation on the prevalence of smoking and exposure to second hand smoke, especially in more deprived urban communities.

Cardiovascular effect of bans on smoking in public places: a systematic review and meta-analysis

OBJECTIVES

A systematic review and a meta-analysis were performed to determine the association between public smoking bans and risk for hospital admission for acute myocardial infarction (AMI).

BACKGROUND

Secondhand smoke (SHS) is associated with a 30% increase in risk of AMI, which might be reduced by prohibiting smoking in work and public places.

METHODS

PubMed, EMBASE, and Google Scholar databases plus bibliographies of relevant studies and reviews were searched for peer-reviewed original articles published from January 1, 2004, through April 30, 2009, using the search terms "smoking ban" and "heart" or "myocardial infarct." Investigators supplied additional data. All published peer-reviewed original studies identified were included. Incidence rates of AMI per 100,000 person-years before and after implementation of the smoking bans and incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were calculated. Random effects meta-analyses estimated the overall effect of the smoking bans. Funnel plot and meta-regression assessed heterogeneity among studies.

RESULTS

Using 11 reports from 10 study locations, AMI risk decreased by 17% overall (IRR: 0.83, 95% CI: 0.75 to 0.92), with the greatest effect among younger individuals and nonsmokers. The IRR incrementally decreased 26% for each year of observation after ban implementation.

CONCLUSIONS

Smoking bans in public places and workplaces are significantly associated with a reduction in AMI incidence, particularly if enforced over several years.

Secondhand smoke and respiratory symptoms among adolescent current smokers

OBJECTIVE

No study has ever reported the association between persistent respiratory symptoms and exposure to secondhand smoke (SHS) in adolescent smokers. The impact of SHS exposure on child health could be largely underestimated by not taking into account such effects. We investigated the association between exposure to SHS and respiratory symptoms among adolescent current smokers.

METHODS

A total of 32506 students aged 11 to 20 years from 85 randomly selected secondary schools in Hong Kong completed a self-administered questionnaire that included persistent respiratory symptoms (for 3 consecutive months in the past 12 months), number of days of SHS exposure per week at home and outside home, smoking status, amount of active smoking, and other basic demographic characteristics and socioeconomic status.

RESULTS

Adolescent current smokers who were exposed to SHS at home 1 to 4 and 5 to 7 days/wk were 50% (95% confidence interval [CI]: 3%-121%) and 77% (95% CI: 5%-199%) more likely, respectively, to report respiratory symptoms compared with those who were unexposed (P = .01 for trend). The corresponding figures for exposure outside home were 41% (95% CI: 3%-94%) and 85% (95% CI: 31%-161%; P = .004 for trend). Such associations were also observed among never-smokers, but they were weaker than those among current smokers (P < .01 for interaction).

CONCLUSIONS

This is the first evidence that SHS exposure is associated with increased risks for persistent respiratory symptoms among adolescent current smokers. Health promotion programs should aim at SHS reduction as well as smoking cessation among adolescent smokers.

Declines in acute myocardial infarction after smoke-free laws and individual risk attributable to secondhand smoke

BACKGROUND

The estimated effects of recent pubic and workplace smoking restriction laws suggest that they produce significant declines in community rates of heart attack. The consistency of these declines with existing estimates of the relative risk of heart attack in individuals attributable to passive smoking exposure is poorly understood. The objective is to determine the consistency of estimates of reductions in community rates of heart attacks resulting from smoking restriction laws with estimates of the relative risk of heart disease in individuals exposed to passive smoking.

METHODS AND RESULTS

Meta-analyses of existing estimates of declines in community rates were compared with a mathematical model of the relationship between individual risk and community rates. The outcome measure is the ratio of community rates of acute myocardial infarction (after divided by before implementation of a smoking restriction law). There is a significant drop in the rate of acute myocardial infarction hospital admissions associated with the implementation of strong smoke-free legislation. The primary reason for heterogeneity in results of different studies is the duration of follow-up after adoption of the law. The pooled random-effects estimate of the rate of acute myocardial infarction hospitalization 12 months after implementation of the law is 0.83 (95% confidence interval, 0.80 to 0.87), and this benefit grows with time. This drop in admissions is consistent with a range of plausible individual risk and exposure scenarios.

CONCLUSIONS

Passage of strong smoke-free legislation produces rapid and substantial benefits in terms of reduced acute myocardial infarctions, and these benefits grow with time.

Chronic residential exposure to particulate matter air pollution and systemic inflammatory markers

BACKGROUND

Long-term exposure to urban air pollution may accelerate atherogenesis, but mechanisms are still unclear. The induction of a low-grade systemic inflammatory state is a plausible mechanistic pathway.

OBJECTIVES

We analyzed the association of residential long-term exposure to particulate matter (PM) and high traffic with systemic inflammatory markers.

METHODS

We used baseline data from the German Heinz Nixdorf Recall Study, a population-based, prospective cohort study of 4,814 participants that started in 2000. Fine PM [aerodynamic diameter <or= 2.5 microm (PM(2.5))] exposure based on a small-scale dispersion and chemistry transport model was assigned to each home address. We calculated distances between residences and major roads. Long-term exposure to air pollution (annual PM(2.5) and distance to high traffic) and concentration of inflammatory markers [high-sensitivity C-reactive protein (hs-CRP) and fibrinogen] on the day of the baseline visit were analyzed with sex-stratified multiple linear regression, controlling for individual-level risk factors.

RESULTS

In the adjusted analysis, a cross-sectional exposure difference of 3.91 microg/m(3) in PM(2.5) (interdecile range) was associated with increases in hs-CRP of 23.9% [95% confidence interval (CI), 4.1 to 47.4%] and fibrinogen of 3.9% (95% CI, 0.3 to 7.7%) in men, whereas we found no association in women. Chronic traffic exposure was not associated with inflammatory markers. Short-term exposures to air pollutants and temperature did not influence the results markedly.

CONCLUSIONS

Our study indicates that long-term residential exposure to high levels of PM(2.5) is associated with systemic inflammatory markers in men. This might provide a link between air pollution and coronary atherosclerosis.

Using indoor air quality monitoring in 6 counties to change policy in North Carolina

INTRODUCTION

Indoor air quality monitoring has become a valuable tool for states wanting to assess levels of particulate matter before and after smoke-free policies are implemented. However, many states face barriers in passing comprehensive smoke-free legislation, making such study comparisons unlikely. We used indoor air monitoring data to educate decision makers about the value of comprehensive smoke-free laws in a state with strong historical ties to tobacco.

METHODS

We trained teams in 6 counties in North Carolina to monitor air quality in hospitality venues with 1 of 3 possible smoking policy designations: 1) smoke-free, 2) separate smoking and nonsmoking sections (mixed), or 3) smoking allowed in all areas. Teams monitored 152 venues for respirable suspended particles that were less than 2.5 microm in diameter and collected information on venue characteristics. The data were combined and analyzed by venue policy and by county. Our findings were presented to key decision makers, and we then collected information on media publicity about these analyses.

RESULTS

Overall, smoke-free venues had the lowest particulate matter levels (15 microg/m3), well below established Environmental Protection Agency standards. Venues with mixed policies and venues that permitted smoking in all areas had particulate matter levels that are considered unhealthy by Environmental Protection Agency standards. The media coverage of our findings included newspaper, radio, and television reports. Findings were also discussed with local health directors, state legislators, and public health advocates.

CONCLUSION

Study data have been used to quantify particulate matter levels, raise awareness about the dangers of secondhand smoke, build support for evidence-based policies, and promote smoke-free policies among policy makers. The next task is to turn this effort into meaningful policy change that will protect everyone from the harms of secondhand smoke.

Hookah (Shisha, Narghile) Smoking and Environmental Tobacco Smoke (ETS). A critical review of the relevant literature and the public health consequences

Hookah (narghile, shisha, "water-pipe") smoking is now seen by public health officials as a global tobacco epidemic. Cigarette Environmental Tobacco Smoke (ETS) is classically understood as a combination of Side-Stream Smoke (SSS) and Exhaled Main-Stream Smoke (EMSS), both diluted and aged. Some of the corresponding cigarette studies have served as the scientific basis for stringent legislation on indoor smoking across the world. Interestingly, one of the distinctive traits of the hookah device is that it generates almost no SSS. Indeed, its ETS is made up almost exclusively by the smoke exhaled by the smoker (EMSS), i.e. which has been filtered by the hookah at the level of the bowl, inside the water, along the hose and then by the smoker's respiratory tract itself. The present paper reviews the sparse and scattered scientific evidence available about hookah EMSS and the corresponding inferences that can be drawn from the composition of cigarette EMSS. The reviewed literature shows that most of hookah ETS is made up of EMSS and that the latter qualitatively differs from MSS. Keeping in mind that the first victim of passive smoking is the active smoker her/himself, the toxicity of hookah ETS for non-smokers should not be overestimated and hyped in an unscientific way.

Cardiovascular benefits of smoking regulations: The effect of decreased exposure to passive smoking

OBJECTIVES

Decreases in population rates of acute myocardial infarction (AMI) have been repeatedly seen in the first months after the introduction of regulations banning smoking in public places. By decreasing the exposure to passive smoking and its acute cardiovascular effects, smoking regulations may cause an immediate drop in AMI incidence, beginning from the initial days after their introduction. Using simulations, we quantified this expected decrease.

METHODS

Expected AMI decreases were estimated using several parameters, including prevalence of exposure to passive and active smoking, relative risks of AMI associated with active and passive smoking, decrease in exposure to passive smoking after the introduction of the regulation, and level of susceptibility of active smokers to exposure to passive smoking.

RESULTS

After evaluating several possible combinations of these parameters, we found that AMI reductions of 5-15% seem likely. For example, a scenario with a population average of 5 hours per week of overall exposure to passive smoking, a 50% reduction in this exposure after the introduction of the regulation, an acute relative risk (RR) of AMI of 4.5 in the first hour after passive smoking exposure, and similar susceptibility to passive smoking among both active and passive smokers translates into a 8.6% decrease in AMI.

CONCLUSIONS

Smoking regulations can cause immediate and relevant decreases in AMI through the prevention of exposure to passive smoking.

Smoking prevention: obstacles and possibilities

A brief overview is given of the disastrous effects of tobacco smoking on health, the environment and the economy. Obstacles for prevention are exemplified by the strong addictive property of nicotine, the ruthlessness and greed of the tobacco industry, and the ambivalence still demonstrated by the political and the health professional community in the fight against tobacco. A successful comprehensive tobacco control strategy is recognized and promoted by the first global health convention, the World Health Organization (WHO) Framework Convention on Tobacco Control. WHO has great expectations of the health community to support the implementation of the convention: who else has a greater responsibility?

Smoke-free legislation and hospitalizations for acute coronary syndrome

BACKGROUND

Previous studies have suggested a reduction in the total number of hospital admissions for acute coronary syndrome after the enactment of legislation banning smoking in public places. However, it is unknown whether the reduction in admissions involved nonsmokers, smokers, or both.

METHODS

Since the end of March 2006, smoking has been prohibited by law in all enclosed public places throughout Scotland. We collected information prospectively on smoking status and exposure to secondhand smoke based on questionnaires and biochemical findings from all patients admitted with acute coronary syndrome to nine Scottish hospitals during the 10-month period preceding the passage of the legislation and during the same period the next year. These hospitals accounted for 64% of admissions for acute coronary syndrome in Scotland, which has a population of 5.1 million.

RESULTS

Overall, the number of admissions for acute coronary syndrome decreased from 3235 to 2684--a 17% reduction (95% confidence interval, 16 to 18)--as compared with a 4% reduction in England (which has no such legislation) during the same period and a mean annual decrease of 3% (maximum decrease, 9%) in Scotland during the decade preceding the study. The reduction in the number of admissions was not due to an increase in the number of deaths of patients with acute coronary syndrome who were not admitted to the hospital; this latter number decreased by 6%. There was a 14% reduction in the number of admissions for acute coronary syndrome among smokers, a 19% reduction among former smokers, and a 21% reduction among persons who had never smoked. Persons who had never smoked reported a decrease in the weekly duration of exposure to secondhand smoke (P<0.001 by the chi-square test for trend) that was confirmed by a decrease in their geometric mean concentration of serum cotinine from 0.68 to 0.56 ng per milliliter (P<0.001 by the t-test).

CONCLUSIONS

The number of admissions for acute coronary syndrome decreased after the implementation of smoke-free legislation. A total of 67% of the decrease involved nonsmokers. However, fewer admissions among smokers also contributed to the overall reduction.

Smoking reduction fails to improve clinical and biological markers of cardiac disease: a randomized controlled trial

Cigarette reduction has been proposed as a treatment goal for smokers who are not interested in stopping completely. This randomized controlled trial was designed to determine the effect of a smoking reduction intervention on smoking behavior, symptoms of heart disease, and biomarkers of tobacco exposure. It included 152 patients with heart disease who did not intend to stop smoking in the next 30 days. Participants were randomly assigned to smoking reduction (SR) or usual care (UC). SR subjects received counseling and nicotine replacement therapy to encourage > or =50% reduction in cigarettes per day (CPD). They were followed at 1, 3, 6, 12 and 18 months to assess smoking, heart disease symptoms, quality of life and nicotine, cotinine, carbon monoxide (CO), white blood cell (WBC) count, fibrinogen, hs-C-reactive protein (hs-CRP), F2-isoprostane, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides (total NNAL), and 1-hydroxypyrene (1-HOP). At 6 months SR participants reduced by 10.9 CPD, compared with 7.4 CPD in UC (difference NS). At 18 months, 9/78 SR vs. 9/74 UC participants quit smoking. There were no significant differences between treatment groups in angina, quality of life or adverse events, nicotine, cotinine, CO, WBC count, fibrinogen, hs-CRP, F2-isoprostane, total NNAL or 1-HOP levels at any time point. To determine if smoking reduction, regardless of treatment condition, was associated with improved outcomes, we compared all subjects at 6 months to baseline (mean reduction in CPD from 27.4 to 18.1, p<.01). There were no significant changes in outcome variables except CO, which decreased by 5.5 ppm (p<.01). There were also no significant improvements considering only subjects who reduced by > or =50%, or those who had no history of reduction prior to enrollment in the study. The SR intervention did not significantly reduce CPD or toxin exposure, or improve smoking cessation or clinical outcomes compared to UC. These results emphasize the importance of abstinence for smokers with heart disease to minimize health risks from tobacco.

The diffusion and impact of clean indoor air laws

Over the past quarter century, primarily as a result of scientific discovery, citizen advocacy, and legislative action, comprehensive clean indoor air laws have spread rapidly throughout the world. Laws that establish completely smoke-free indoor environments have many relative advantages including being low cost, safe, effective, and easy to implement. The diffusion of these laws has been associated with a dramatic and rapid reduction in population levels of serum cotinine among nonsmokers and has also contributed to a reduction in overall cigarette consumption among smokers, with no adverse economic impact, except to the tobacco industry. Currently, nearly half of the U.S. population lives in jurisdictions with some combination of completely smoke-free workplaces, restaurants, or bars. The diffusion of clean indoor air laws is spreading rapidly throughout the world, stimulated by the first global health treaty, the Framework Convention on Tobacco Control.

Implications of a public smoking ban

OBJECTIVES

Legislation to ban smoking in public places is currently a major area of interest across Canada. The main objectives of the study were to 1) determine the effect of the smoking ban on incidence of acute myocardial infarction, 2) determine if the new legislation altered population-based smoking prevalence, and 3) measure public support for the public smoking ban.

METHODS

The city of Saskatoon initiated a public smoking ban on July 1, 2004. We retrospectively reviewed all hospital discharges for acute MI from July 2000 to June 2005. We reviewed CCHS survey information on smoking prevalence for Saskatoon, Saskatchewan and Canada from 2003 to 2005. We prospectively contacted 1,255 Saskatoon residents by telephone to determine support for the public smoking ban.

RESULTS

The age-standardized incidence rate of acute MI fell from 176.1 (95% CI 165.3-186.8) cases per 100,000 population (July 1, 2000 to June 30, 2004) to 152.4 (95% CI 135.3-169.3) cases per 100,000 population (July 1, 2004 to June 30, 2005). Smoking prevalence in Saskatoon fell from 24.1% in 2003 (95% CI 20.4-27.7) to 18.2% in 2005 (95% CI 15.7-20.9) while smoking prevalence in Saskatchewan remained unchanged at 23.8% (95% CI 22.6-25.3) and Canada reduced from 22.9% (95% CI 22.5-23.3) to 21.3% (95% CI 20.8-21.8). Seventy-nine percent of Saskatoon residents believed the smoking ban was a good idea.

INTERPRETATION

The public smoking ban in Saskatoon, Canada, is associated with reduced incidence rates of acute MI, lower smoking prevalence and high levels of public support.

Effect of the Italian smoking ban on population rates of acute coronary events

BACKGROUND

Several countries in the world have not yet prohibited smoking in public places. Few studies have been conducted on the effects of smoking bans on cardiac health. We evaluated changes in the frequency of acute coronary events in Rome, Italy, after the introduction of legislation that banned smoking in all indoor public places in January 2005.

METHODS AND RESULTS

We analyzed acute coronary events (out-of-hospital deaths and hospital admissions) between 2000 and 2005 in city residents 35 to 84 years of age. We computed annual standardized rates and estimated rate ratios by comparing the data from prelegislation (2000-2004) and postlegislation (2005) periods. We took into account several time-related potential confounders, including particulate matter (PM10) air pollution, temperature, influenza epidemics, time trends, and total hospitalization rates. The reduction in acute coronary events was statistically significant in 35- to 64-year-olds (11.2%, 95% CI 6.9% to 15.3%) and in 65- to 74-year-olds (7.9%, 95% CI 3.4% to 12.2%) after the smoking ban. No evidence was found of an effect among the very elderly. The reduction tended to be greater in men and among lower socioeconomic groups.

CONCLUSIONS

We found a statistically significant reduction in acute coronary events in the adult population after the smoking ban. The size of the effect was consistent with the pollution reduction observed in indoor public places and with the known health effects of passive smoking. The results affirm that public interventions that prohibit smoking can have enormous public health implications.

Tobacco industry efforts undermining evidence linking secondhand smoke with cardiovascular disease

BACKGROUND

The scientific consensus that secondhand smoke (SHS) increases cardiovascular disease (CVD) risk by 30% is based on epidemiological and biological evidence. The tobacco industry has contested this evidence that SHS causes CVD, but how and why they have done it has not been described.

METHODS AND RESULTS

About 50 million pages of tobacco industry documents were searched using general keywords and names of industry consultants and scientists. Tobacco industry-funded epidemiological analyses of large data sets were used to argue against an epidemiological association between SHS and CVD and smoke-free regulations, but these analyses all suffered from exposure misclassification problems that biased the results toward the null. More recent industry-funded publications report an increased risk of CVD associated with SHS but claim a low magnitude of risk. When early tobacco industry-funded work demonstrated that SHS increased atherosclerosis, the industry criticized the findings and withdrew funding. RJ Reynolds focused on attacking the biological plausibility of the association between SHS and CVD by conducting indirect platelet aggregation studies, exposure chamber experiments, and literature reviews. Although these studies also suffered from exposure misclassification problems, several produced results that were consistent with a direct effect of SHS on blood and vascular function. Instead, RJ Reynolds attributed these results to an unproven epinephrine-related stress response from odor or large smoke exposure, which supported their regulatory and "reduced-harm" product development efforts. Philip Morris' recent "reduced-harm" efforts seem supportive of a similar corporate agenda.

CONCLUSIONS

The tobacco industry attempted to undermine the evidence that SHS causes CVD to fight smoke-free regulations while developing approaches to support new products that claim to reduce harm. The industry interest in preserving corporate viability has affected the design and interpretation of their cardiovascular studies, indicating the need for great caution in current debates about future tobacco industry regulation and development of reduced-harm tobacco products.

Is the tobacco control movement misrepresenting the acute cardiovascular health effects of secondhand smoke exposure? An analysis of the scientific evidence and commentary on the implications for tobacco control and public health practice

While chronic exposure to secondhand smoke has been well recognized as a cause of heart disease in nonsmokers, there has been recent speculation about the potential acute cardiovascular effects of transient exposure to secondhand smoke among nonsmokers; in particular, the possibility that such exposure could increase the risk of acute myocardial infarction even in an otherwise healthy nonsmoker. This paper reviews the claims being made by a number of anti-smoking and public health groups regarding the acute cardiovascular effects of secondhand smoke exposure among otherwise healthy adults, analyzes the validity of these claims based on a review of the scientific evidence, and discusses the implications of the findings for tobacco control and public health practice. Based on the analysis, it appears that a large number of anti-smoking organizations are making inaccurate claims that a single, acute, transient exposure to secondhand smoke can cause severe and even fatal cardiovascular events in healthy nonsmokers. The dissemination of inaccurate information by anti-smoking groups to the public in support of smoking bans is unfortunate because it may harm the tobacco control movement by undermining its credibility, reputation, and effectiveness. Disseminating inaccurate information also represents a violation of basic ethical principles that are a core value of public health practice that cannot and should not be sacrificed, even for a noble end such as protecting nonsmokers from secondhand smoke exposure. How the tobacco control movement responds to this crisis of credibility will go a long way towards determining the future effectiveness of the movement and its ability to continue to save lives and protect the public's health.

Declines in hospital admissions for acute myocardial infarction in New York state after implementation of a comprehensive smoking ban

OBJECTIVES

Reductions in exposure to environmental tobacco smoke have been shown to attenuate the risk of cardiovascular disease. We examined whether the 2003 implementation of a comprehensive smoking ban in New York State was associated with reduced hospital admissions for acute myocardial infarction and stroke, beyond the effect of moderate, local and statewide smoking restrictions, and independent of secular trends.

METHODS

We analyzed trends in county-level, age-adjusted, monthly hospital admission rates for acute myocardial infarction and stroke from 1995 to 2004 to identify any association between admission rates and implementation of the smoking ban. We used regression models to adjust for the effects of pre-existing smoking restrictions, seasonal trends in admissions, differences across counties, and secular trends.

RESULTS

In 2004, there were 3813 fewer hospital admissions for acute myocardial infarction than would have been expected in the absence of the comprehensive smoking ban. Direct health care cost savings of $56 million were realized in 2004. There was no reduction in the number of admissions for stroke.

CONCLUSIONS

Hospital admission rates for acute myocardial infarction were reduced by 8% as a result of a comprehensive smoking ban in New York State after we controlled for other relevant factors. Comprehensive smoking bans constitute a simple, effective intervention to substantially improve the public's health.

Changes in exposure of adult non-smokers to secondhand smoke after implementation of smoke-free legislation in Scotland: national cross sectional survey

OBJECTIVE

To measure change in adult non-smokers' exposure to secondhand smoke in public and private places after smoke-free legislation was implemented in Scotland.

DESIGN

Repeat cross sectional survey.

SETTING

Scotland.

PARTICIPANTS

Scottish adults, aged 18 to 74 years, recruited and interviewed in their homes.

INTERVENTION

Comprehensive smoke-free legislation that prohibits smoking in virtually all enclosed public places and workplaces, including bars, restaurants, and cafes.

OUTCOME MEASURES

Salivary cotinine, self reported exposure to smoke in public and private places, and self reported smoking restriction in homes and in cars.

RESULTS

Overall, geometric mean cotinine concentrations in adult non-smokers fell by 39% (95% confidence interval 29% to 47%), from 0.43 ng/ml at baseline to 0.26 ng/ml after legislation (P<0.001). In non-smokers from non-smoking households, geometric mean cotinine concentrations fell by 49% (40% to 56%), from 0.35 ng/ml to 0.18 ng/ml (P<0.001). The 16% fall in cotinine concentrations in non-smokers from smoking households was not statistically significant. Reduction in exposure to secondhand smoke was associated with a reduction after legislation in reported exposure to secondhand smoke in public places (pubs, other workplaces, and public transport) but not in homes and cars. We found no evidence of displacement of smoking from public places into the home.

CONCLUSIONS

Implementation of Scotland's smoke-free legislation has been accompanied within one year by a large reduction in exposure to secondhand smoke, which has been greatest in non-smokers living in non-smoking households. Non-smokers living in smoking households continue to have high levels of exposure to secondhand smoke.

The impact of a smoking ban on hospital admissions for coronary heart disease

OBJECTIVE

In March 2002, the city of Bowling Green, Ohio, implemented a clean indoor air ordinance banning smoking in workplaces and public places. This study evaluates the effect of this ordinance on hospital admissions for smoking-related diseases.

METHODS

A quasi-experimental design with interrupted time-series was used including a matched control city (Kent, Ohio) with no clean indoor air ordinance. Data on hospital admissions during the period of January 1999 to June 2005 were analyzed using Autoregressive Integrated Moving Average (ARIMA) models.

RESULTS

A reduction in admission rates for smoking-related diseases was achieved in Bowling Green compared to the control city. The largest reduction was for coronary heart disease, where rates were decreased significantly by 39% after 1 year and by 47% after 3 years following the implementation of the ordinance. ARIMA models revealed a statistically significant downward trend in monthly admission rates for coronary heart disease (Bowling Green, omega=-1.69, p=0.036 vs. Kent, omega=-1.14, p=0.183) and support the hypothesis that the ordinance had a significant impact on admission rates for coronary heart disease.

CONCLUSION

The findings of this study suggest that clean indoor air ordinances lead to a reduction in hospital admissions for coronary heart disease, thus reducing health care costs.