Environmental tobacco smoke and lung function in employees who never smoked: the Scottish MONICA study

Evaluation of exposure to secondhand smoke and serum level of interleukin 18 in non-smokers

Objective

Smoking is one significant global health care problems, that not only affects the users but also endangers the health of people inhaling the smoke (passive smoking/secondhand smoke). The serum level of IL-18, an important regulator of inherent and acquired immune response, is affected by cigarette smoking. The aim of this study was to evaluate the effect of secondhand smoke (SHS) exposure on IL-18 serum level in non-smoker adults.

Methods

In a case-control study, using easy sampling method, 76 non-smokers who were exposed to cigarette smoke for at least 1 h daily during the past year were considered as exposure group, while 76 of their companions without exposure to cigarette smoke (after matching age) were considered as non-exposure group. Serum IL-18 levels were measured for all participants and finally compared between the two groups using Chi-square test. P value < 0.05 was considered to be statistically significant.

Results

The exposure and non-exposure groups included 58 (76.3%) and 25 (32.9%) males, respectively (P < 0.001). The mean ± SD of age for the exposure and non-exposure groups was 35.42 ± 10.37 and 38.47 ± 12.49 years, respectively (P = 0.102). There was no significant difference between the mean serum levels of IL-18 in the exposure (54.81 ± 57.03 ng/ml) and non-exposure (41.49 ± 42.14 ng/ml) groups (P = 0.104).

Conclusion

The exposure to secondhand smoke has no significant effect on serum level of IL-18 in exposed adult individuals. However, more studies with larger sample sizes on different populations are required to confirm these results.

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Smoking is one significant global health care problems.

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That not only affects the users but also endangers the health of people inhaling the smoke.

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The serum level of IL-18, an important regulator of inherent and acquired immune response.

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The exposure to secondhand smoke has no significant effect on serum level of IL-18.

Quality of life and sleep disorders in Tehran Employees Cohort (TEC); Association with secondhand smoking and wealth index

PURPOSE

Second-hand smoke is recognized as a major indoor pollutant. Evidences indicated that Second-hand smoke exposure can influence on not only physical health, but also mental well-being. As the correlation of secondhand smoke exposure with sleep quality and quality of life has not yet been clarified sufficiently, the purpose of this study was to evaluate the association between Second-hand smoke exposure, with sleep quality and quality of life after adjusting for active smoking and other relevant confounders.

METHODS

The participants of this study were 1790 staff in Tehran University of Medical Sciences with different jobs employed in various academic departments (clinical, research, services, educational and technical ones). They participated voluntarily in this research project and completed the informed consent form between 2018 and 2019. A translated questionnaire of Global Adult Tobacco Survey was used to gather information about smoke exposure. When to evaluate the quality of life, the WHOQOL-BREF tool was applied. All statistical analyses were executed using STATA V14 software.

RESULTS

High rate of smoking and also exposure to second-hand smoke significantly increased sleep disorder and reduced the quality of life. In other words, smokers or those who are exposed to second-hand smoke suffer from sleep disturbances and had a poorer physical, psychological, and environmental quality of life. Additionally, the results of multivariate regression analysis demonstrated that the secondhand-smoke group had 1.38 times higher rate of sleep disorder in comparison with non-smokers, that was statistically significant. The women had 2.68 times higher odds of having sleep disorder compared to men. (95 % CI: 2.20 to 3.27). On the other hand, mean score of psychological domain of quality of life in secondhand-smoke group was lower with the size of difference as 0.66 than that in non-smokers, and the difference was statistically significant (p = 0.001).

CONCLUSIONS

Both active smoking and exposure to second hand smoke have a negative impact on sleep quality and quality of life.

Secondhand smoking and neurological disease: a meta-analysis of cohort studies

BACKGROUND

The results of studies on the relationship between secondhand smoking and neurological disease remain controversial. We conducted a meta-analysis to explore the association between secondhand smoking and risk of neurological disease.

METHODS

Literature search was performed in PubMed, Embase and Web of Science through December 2019. We included cohort studies which examined the association between secondhand smoking and risk of neurological disease. According to the type of neurological disease, summary relative risks (RRs) with 95% confidence intervals (CIs) of stroke, cognitive impairment and Parkinson disease (PD) for secondhand smoking exposure were calculated.

RESULTS

A total of 14 unique articles (n=697,185 participants) were eventually included in the analysis. When all studies were pooled, the RR of stroke for secondhand smoking exposure was 1.20 (95% CI: 1.04, 1.38). When studies included only non-smokers, the pooled RR of stroke was 1.20 (95% CI: 1.05, 1.37). Summary RRs of cognitive impairment and PD for secondhand smoking exposure were 1.43 (95% CI: 1.02, 2.00) and 0.83 (95% CI: 0.72, 0.95), respectively. Summary RRs did not change significantly when excluding one study at a time.

CONCLUSIONS

Secondhand smoking was found to be positively associated with risks of stroke and cognitive impairment, while inversely associated with risk of PD. Overall, our finding is a reminder of the need to step up smoking bans to prevent health damage, and also suggests that more researches on biological mechanisms whereby secondhand smoking affect PD may be beneficial to PD prevention and treatment.

Dual exposure to smoking and household air pollution is associated with an increased risk of severe asthma in adults in Brazil

Background

The relationship between smoking, household pollution, dual exposure and severity of asthma in adults has not been sufficiently studied. We examined and compared the effects of cigarette smoking, domestic wood burning pollution and dual exposure (tobacco and wood burning) upon asthma severity in adults.

Methods

This was a cross-sectional study performed with 452 individuals with mild to moderate asthma and 544 patients with severe asthma (previously untreated). Smoking and exposure to wood smoke were identified and quantified through questionnaires to evaluate current and/or previous exposure; objective determination of cigarette exposure was obtained through the measurement of urinary cotinine. Asthma control was evaluated through Asthma Control Questionnaire; and severity was classified according to the Global Initiative for Asthma criteria. Subjects were grouped according to exposure type into 4 groups: smokers, household pollution, dual-exposure and no-exposure. Chi square, Mann-Whitney, and Kruskal-Wallis tests were used for comparisons between groups.

Results

Out of 996 included individuals, 78 (7.8%) were exposed to cigarette smoking alone, 358 (35.9%) to household pollution alone, 155 (15.6%) to the two exposures combined and 405 (40.7%) were not exposed. Compared to unexposed individuals, exposure to household pollution resulted in poorer asthma control, higher proportion of severe asthma, and worse indicators of lung function. The double-exposed individuals were worse off in all the evaluated parameters, and they were significantly worse than subjects with single exposure to household air pollution in relation to asthma severity and lung function. These subjects were predominantly females, older, with longer residence time in rural areas, lower income and lower schooling levels. Multivariate analysis showed that exposure to household pollution and double exposure were predictive factors associated with lack of control and increased severity of asthma.

Conclusions

Exposure to household pollution is associated with poorer control, greater severity, and poorer pulmonary function; double-exposed individuals have a greater risk of severe asthma and decreased lung function than those exposed only to household pollution.

Effects of biomass burning on pulmonary functions in tribal women in northeastern India

Wood smoke causes adverse effects on pulmonary function (PF) in women in developing countries. This study compared PF among rural tribal women in northeastern India among 266 wood users and 82 liquefied petroleum gas (LPG) users, all healthy nonsmoking women from April to July, 2014. PF measurements included FVC, FEV₁, FEV₁/FVC, PEF, and FEF_25-75%. Information on participants' health status, demographic, and socioeconomic characteristics were collected by questionnaire. Multiple linear regressions were performed to compare PF between the two groups, adjusting for potential confounders. Wood users had significantly lower pulmonary values than LPG users: FVC (2.65 vs. 2.85 L, p < .001), FEV₁ (1.46 vs. 1.92 L, p < .001), PEF (1.89 vs. 2.56 L/s, p < .001), and FEF_25-75% (1.12 vs. 1.68 L/s, p < .001) except for FEV₁/FVC (76.5 vs. 75.5 percent, p = .27). Wood use was associated with 7 percent lower FVC, 24 percent lower FEV₁, 1.3 percent lower FEV₁/FVC, 26 percent lower PEF, and 33 percent lower FEEF_25-75% compared to LPG use. Wood use was associated with a 0.27-L decrease in FEV₁, adjusted for covariates. Women cooking with wood had lower PF and more respiratory symptoms and gastritis than those using LPG. Thus, reducing indoor air pollution from biomass burning is needed to protect tribal women's health.

Secondhand tobacco smoke exposure and pulmonary function: a cross-sectional study among non-smoking employees of bar and restaurants in Santiago, Chile

INTRODUCTION

The workplace remains a significant source of secondhand smoke (SHS) exposure. This pollutant is known to be associated with respiratory and cardiovascular problems, but its effects on specific pulmonary function parameters remain largely unexplored. The objectives of this study were to measure SHS exposure among non-smoking employees of bar and restaurants in Santiago, Chile and to evaluate the effects of such exposure on pulmonary function.

METHODS

Cross-sectional design. The study sample included non-smoking workers from 57 restaurants and bars in Santiago, Chile. The outcome variable was pulmonary function and the exposure variables were urine cotinine concentration, a biomarker for current SHS exposure, and years of SHS exposure in the workplace as proxy of chronic exposure. Personal and occupational variables were also recorded. Data analysis was performed using linear regression models adjusted by confounders.

RESULTS

The median age of the workers was 35 years and the median employment duration at the analysed venues was 1 year. Workers in smoking facilities reported greater SHS exposure (36 hours per week) than workers in smoke-free locations (4 hours per week). Urine cotinine levels were inversely correlated with forced vital capacity, but the finding was not statistically significant (β=-0.0002; 95% CI -0.007 to 0.006). Years of exposure to SHS showed to be significantly associated with forced expiratory flow25/75 (β=-0.006; 95% CI -0.010 to -0.0004).

CONCLUSION

These findings suggest that cumulative exposure to SHS at work may contribute to deterioration of pulmonary function in non-smoking employees.

Modeling the effects of indoor passive smoking at home, work, or other households on adult cardiovascular and mental health: the Scottish Health Survey, 2008-2011

Passive smoking has contributed increased risks of cardiovascular disease, mental health, and mortality, but the cumulative effects from work or other households were less studied. Therefore, it was aimed to model the effects of indoor passive smoking from own home, work, and other households in a country-wide, population-based setting. Data in the Scottish Health Survey between 2008 and 2011 after the law banning smoking in public places were analyzed. Information including demographics, lifestyle factors, and self-reported cardiovascular disease and mental health was obtained by household interview. Analyses included chi-square test and survey-weighted logistic regression modeling. After full adjustment, it was observed that being exposed to indoor passive smoking, in particular in more than two places of exposure, was significantly associated with risks of stroke, angina, heart attack, abnormal heart rhythms, and GHQ ≥ 12. The significance remained for angina, GHQ ≥ 12 and probably heart attack in never smokers. The cumulative risks also impacted on sleep problems, self-recognition, making decisions, self-confidence, under strain constantly, depressed, happiness and self-worth. The significance remained for sleep problems, self-confidence, under strain constantly, depressed, and happiness in never smokers. Elimination of indoor passive smoking from different sources should still be a focus in future public health programs.

Association of passive smoking with cognitive impairment in nonsmoking older adults: a systematic literature review and a new study of Chinese cohort

Association of passive smoking with cognitive impairment in older adults is unclear. We carried out a systematic literature review and a new study to determine the association. There were 3 cross-sectional studies published, showing a significant association of passive smoking with cognitive impairment (a relative risk (RR) of about 1.30-1.90). In the new cohort study, we interviewed 1081 never-smoking participants aged ≥ 65 years in China using a standard method of the Geriatric Mental State-Automated Geriatric Examination for Computer Assisted Taxonomy and found a significant association with dose response; multivariate adjusted RR was 1.02 (95% confidence interval 0.67-1.55) in > 0 to 49 exposure level years of passive smoking, 1.57 (1.00-2.47) in 50 to 99, and 2.12 (1.24-3.63) in ≥ 100, trend P = .008. The relationship seems not to be a reverse causality of the effect. Passive smoking could be considered an important risk factor for cognitive impairment in older adults. Avoiding exposure to passive smoking would help to preserve cognitive decline in later life.

The effect of cigarette smoke exposure on vitamin D level and biochemical parameters of mothers and neonates

BACKGROUND

Exposure to cigarette smoke during pregnancy leads to several adverse effects on mother and child. The purpose of this study was to evaluate the effect of being a passive smoker during pregnancy on vitamin D level and related biochemical indices including parathyroid hormone, calcium, phosphorus and alkaline phosphatase in mothers and newborns.

METHODS

One hundred eight pregnant women and their newborns participated in a historical cohort study in two equal groups (n = 54) with and without cigarette smoke exposure. Maternal blood and urine samples and blood samples of umbilical cord were obtained in the delivery room. Concentration of 25-hydroxy vitamin D and related biochemical indices in samples of maternal and cord blood were investigated. Exposure to cigarette smoke was evaluated through questionnaire and maternal urine and umbilical cord serum cotinine levels.

RESULTS

The mean level of 25-hydroxyvitamin D in maternal serum was 9.28 ± 5.19 ng/mlin exposed and 10.75 ± 5.26 ng/ml in non-exposed group(p > 0.05). The mean concentration of 25-hydroxy vitamin D in cord serum was 10.83 ± 6.68 ng/ml in the exposed and 11.05 ± 4.99 ng/ml in the non-exposed group(p > 0.05). The exposed mothers had significantly higher parathyroid hormone level (p = 0.013), lower serum calcium (p = 0.024) and higher serum alkaline phosphatase (p = 0.024). There was a significant correlation between maternal and umbilical cord serum 25-hydroxyvitamin D within both exposed and non-exposed groups (p < 0.001).

CONCLUSION

Maternal exposure to cigarette smoking during pregnancy negatively influences serum calcium level and increase parathyroid hormone and alkaline phosphatase in mothers.

Emerging mechanistic targets in lung injury induced by combustion-generated particles

The mechanism for biological effect following exposure to combustion-generated particles is incompletely defined. The identification of pathways regulating the acute toxicological effects of these particles provides specific targets for therapeutic manipulation in an attempt to impact disease following exposures. Transient receptor potential (TRP) cation channels were identified as "particle sensors" in that their activation was coupled with the initiation of protective responses limiting airway deposition and inflammatory responses, which promote degradation and clearance of the particles. TRPA1, V1, V4, and M8 have a capacity to mediate adverse effects after exposure to combustion-generated particulate matter (PM); relative contributions of each depend upon particle composition, dose, and deposition. Exposure of human bronchial epithelial cells to an organic extract of diesel exhaust particle was followed by TRPV4 mediating Ca(++) influx, increased RAS expression, mitogen-activated protein kinase signaling, and matrix metalloproteinase-1 activation. These novel pathways of biological effect can be targeted by compounds that specifically inhibit critical signaling reactions. In addition to TRPs and calcium biochemistry, humic-like substances (HLS) and cell/tissue iron equilibrium were identified as potential mechanistic targets in lung injury after particle exposure. In respiratory epithelial cells, iron sequestration by HLS in wood smoke particle (WSP) was associated with oxidant generation, cell signaling, transcription factor activation, and release of inflammatory mediators. Similar to WSP, cytotoxic insoluble nanosized spherical particles composed of HLS were isolated from cigarette smoke condensate. Therapies that promote bioelimination of HLS and prevent the disruption of iron homeostasis could function to reduce the harmful effects of combustion-generated PM exposure.

The impact of smoking in the home on the health outcomes of non-smoker occupants in the UK

Smoking in the home remains a key source of exposure to secondhand smoke for non-smokers, particularly since the UK public smoking ban in 2007. A systematic literature review was conducted to identify all UK evidence on the impact of secondhand smoke exposure in the home on health and behavioural outcomes in non-smoker occupants. MEDLINE, EMBASE and the Cochrane Library were searched to identify all relevant UK empirical studies from 2000 to June 2011. A qualitative overview of the evidence is presented. Exposure to secondhand smoke in UK homes was found to be associated with serious negative health effects in non-smokers, including significantly increased risk of meningococcal carriage (p < 0.001) and disease (p = 0.05) in children and adolescents, cognitive impairment (p < 0.001) in adults, a higher rate of medically attended accidents in children with smoking mothers (p < 0.01), and for non-smoking women, a significant decrease in infant birth weight (p = 0.007). Living in a smoking household significantly increased the risk of future regular smoking in children (p < 0.001). In conclusion, this systematic review has identified strong evidence of an association between secondhand smoke exposure in the home and several serious health conditions. This finding highlights the importance of educating current smokers on the consequences of non-smoker exposure to smoking in the home.

Passive smoking, pulmonary function and bronchial hyper-responsiveness among indoor sanitary workers

Pulmonary function parameters of 21 cleaning/sanitary women workers who have never smoked, exposed to environmental tobacco smoke (ETS) at work were compared with 34 non-exposed women workers of comparable age and other work characteristics. The studied subjects were subjected to an interview questionnaire, pulmonary function measurements, bronchial responsiveness assessment and clinical chest examination. A higher prevalence of dyspnea was found (42.9%) among exposed compared to (14.7%) among the non-exposed workers (p=0.019), also wheezing (52.4% vs. 11.8%; p=0.001). Pulmonary measurements showed a lower FVC, FEV(1)/FVC and FEF(75) values among exposed compared to non-exposed (p<0.05), and a higher prevalence of borderline bronchial hyper-responsiveness (38.1% vs. 11.8%; p=0.021) in the exposed workers. This study provides evidence of adverse respiratory effects in sanitary/cleaning women workers associated with passive smoking in the workplace. The findings support a stricter implementation measures to protect respiratory health of all workers.

Bronchial asthma and COPD due to irritants in the workplace - an evidence-based approach

BACKGROUND

Respiratory irritants represent a major cause of occupational obstructive airway diseases. We provide an overview of the evidence related to irritative agents causing occupational asthma or occupational COPD.

METHODS

We searched MEDLINE via PubMed. Reference lists of relevant reviews were also screened. The SIGN grading system was used to rate the quality of each study. The modified RCGP three-star system was used to grade the body of evidence for each irritant agent regarding its causative role in either occupational asthma or occupational COPD.

RESULTS

A total of 474 relevant papers were identified, covering 188 individual agents, professions or work-sites. The focus of most of the studies and the predominant diagnosis was occupational asthma, whereas occupational COPD arose only incidentally.The highest level assigned using the SIGN grading was 2+ (well-conducted systematic review, cohort or case-control study with a low risk of confounding or bias). According to the modified RCGP three-star grading, the strongest evidence of association with an individual agent, profession or work-site ("**") was found for 17 agents or work-sites, including benzene-1,2,4-tricarboxylicacid-1,2-anhydride, chlorine, platinum salt, isocyanates, cement dust, grain dust, animal farming, environmental tobacco smoke, welding fumes or construction work. Phthalic anhydride, glutaraldehyde, sulphur dioxide, cotton dust, cleaning agents, potrooms, farming (various), foundries were found to be moderately associated with occupational asthma or occupational COPD ("*[+]").

CONCLUSION

This study let us assume that irritant-induced occupational asthma and especially occupational COPD are considerably underreported. Defining the evidence of the many additional occupational irritants for causing airway disorders will be the subject of continued studies with implications for diagnostics and preventive measures.

Diesel exhaust particles and airway inflammation

PURPOSE OF REVIEW

Epidemiologic investigation has associated traffic-related air pollution with adverse human health outcomes. The capacity of diesel exhaust particles (DEPs), a major emission source air pollution particle, to initiate an airway inflammation has subsequently been investigated. We review the recent controlled human exposures to diesel exhaust and DEPs, and summarize the investigations into the associations between this emission source air pollution particle and airway inflammation.

RECENT FINDINGS

Using bronchoalveolar lavage, bronchial biopsies, and sputum collection, studies have demonstrated inflammation in the airways of healthy individuals after exposure to diesel exhaust and DEPs. This inflammation has included neutrophils, eosinophils, mast cells, and lymphocytes. Elevated expression and concentrations of inflammatory mediators have similarly been observed in the respiratory tract after diesel exhaust and DEP exposure. An increased sensitivity of asthmatic individuals to the proinflammatory effects of DEPs has not been confirmed.

SUMMARY

Inflammation after diesel exhaust and DEP exposure is evident at higher concentrations only; there appears to be a threshold dose for DEPs approximating 300 μg/m. The lack of a biological response to DEPs at lower concentrations may reflect a contribution of gaseous constituents or interactions between DEPs and gaseous air pollutants to the human inflammatory response and function loss.

Composition of air pollution particles and oxidative stress in cells, tissues, and living systems

Epidemiological studies demonstrated an association between increased levels of ambient air pollution particles and human morbidity and mortality. Production of oxidants, either directly by the air pollution particles or by the host response to the particles, appears to be fundamental in the biological effects seen after exposure to particulate matter (PM). However, the precise components and mechanisms responsible for oxidative stress following PM exposure are yet to be defined. Direct oxidant generation by air pollution particles is attributed to organic and metal components. Organic compounds generate an oxidative stress through redox cycling of quinone-based radicals, by complexing of metal resulting in electron transport, and by depletion of antioxidants by reactions between quinones and thiol-containing compounds. Metals directly support electron transport to generate oxidants and also diminish levels of antioxidants. In addition to direct generation of oxidants by organic and metal components, cellular responses contribute to oxidative stress after PM exposure. Reactive oxygen species (ROS) production occurs in the mitochondria, cell membranes, phagosomes, and the endoplasmic reticulum. Oxidative stress following PM exposure initiates a series of cellular reactions that includes activation of kinase cascades and transcription factors and release of inflammatory mediators, which ultimately lead to cell injury or apoptosis. Consequently, oxidative stress in cells and tissues is a central mechanism by which PM exposure leads to injury, disease, and mortality.

Association of self-reported passive smoking in pregnant women with cotinine level of maternal urine and umbilical cord blood at delivery

Passive smoking during pregnancy leads to adverse effects on mother and infant. The present investigation was designed to evaluate the association between maternal reported passive smoking with the cotinine concentration of maternal urine and umbilical cord blood at delivery and to determine the accuracy of maternal reporting of exposure to cigarette smoke during pregnancy. This was a cross-sectional study. From the 108 non-smoker pregnant women who were referred for delivery, 54 were passive smokers. Urine samples were collected from the mothers in the delivery room and blood samples after birth were taken from the umbilical cord. Passive smoking was evaluated through questionnaire and cotinine level of urine and umbilical cord blood. The geometric mean cotinine concentration of the maternal urine and the umbilical cord serum were, respectively, 27.4 ± 29.96 ng/mL and 3.71 ± 1.22 ng/mL in the exposed group (P < 0.001) and 0.75 ± 2.29 and 0.40 ± 0.63 in the non-exposed group (P < 0.001). There was a statistically significant correlation between maternal urinary and umbilical cord serum level of cotinine (P < 0.001, r = 0.58). Significant associations were shown between maternal reports of exposure to cigarette smoking with cotinine level of urine (kappa = 96%) and umbilical cord (kappa = 98%) (P < 0.001). This study shows that the pregnant woman's report of passive smoking during pregnancy in Iran is accurate. The questionnaire is an appropriate method to evaluate smoke exposure and could replace cotinine measurement.

Mechanism of asthmatic exacerbation by ambient air pollution particles

In the previous two to three decades, the prevalence of asthma has risen in numerous countries of the world. Correlating with this elevated prevalence of asthma, societies have observed increased air pollution from specific sources. Studies have implicated certain pollutants in asthmatic exacerbation. Particulate matter (PM) is the pollutant most frequently identified with worsening of this airway disease. PM is a temporally and spatially shifting suspension of solids and liquids originating from both natural and anthropogenic sources. Exposures to elevated levels of PM have been associated with asthmatic exacerbations by employing a diverse array of end points, including respiratory symptoms, use of medication, medical visits, emergency room visits, hospital admissions and pulmonary function decrements. Pertinent to worsening of asthma by ambient air PM, there are other particle-associated exposures that similarly precipitate asthmatic exacerbations. These include traffic-associated pollutants, diesel exhaust, emissions from gas and wood stoves, burning of biomass and environmental tobacco smoke. It is widely accepted that the biological effects exerted by all particle exposures result from oxidative stress. This stimulates cell signaling, transcription factor activation and mediator release in the respiratory tract, culminating in inflammation. Other postulated mechanisms for asthmatic exacerbation following PM exposure include an impact on the incidence of infections and adjuvant effects.

Effects of Passive Smoking at Work on Respiratory Symptoms, Lung Function, and Bronchial Responsiveness in Never-Smoking Office Cleaning Women

This cross-sectional study compares respiratory symptoms, lung function, and bronchial responsiveness between 27 office cleaning women exposed to environmental tobacco smoke at work and 57 unexposed controls. The age range of both groups was 24 to 56 years, and none of the women had ever smoked. Information on respiratory symptoms, cleaning work history, and passive smoking in the workplace were obtained with a questionnaire. The subjects also took a skin prick test to common inhalant allergens, a lung function test, and a histamine challenge. Despite smoking restriction in indoor environments, we found a high prevalence of passive smokers in the workplace (32.1 %). In these subjects we found a significantly higher prevalence of wheezing with breathlessness (25.9 % vs. 8.8 %; P=0.036), wheezing without cold (25.9 % vs. 7.0 %; P=0.016), and breathlessness after effort (29.6 % vs. 8.8 %; P=0.014) than in control subjects. Objective measurements showed a significantly lower MEF25 (53.6 % vs. 63.7 %; P=0.001) and a significantly higher prevalence of borderline bronchial hyperresponsiveness (22.2 % vs. 7.0 %; P=0.044) in the passive smokers in the workplace. This study provides evidence of adverse respiratory effects in office cleaning women associated with passive smoking in the workplace. Our findings support a stricter implementation of the current national law to protect respiratory health of all workers.

Disruption of Iron Homeostasis as a Mechanism of Biologic Effect by Ambient Air Pollution Particles

Several features of the clinical presentation and changes in physiology and pathology following exposure to many diverse ambient air pollution particles are comparable, suggesting a common mechanism for their biological effect. We propose that a mechanism of biological effect common to many ambient air pollution particles is a disruption of iron homeostasis in cells and tissues. Among traits shared by every particle-related lung injury is the introduction of a solid-liquid interface into the respiratory tract. All surfaces of particulate matter have some concentration of oxygen-containing functional groups. As a result of its electropositivity, Fe(3+) has a high affinity for oxygen-donor ligands and will react with these groups at the particle surface. Retained particles accumulate metal from available sources in a cell and tissue, and this complexed iron mediates oxidant generation. In addition to complexation onto the solid-liquid interface provided by the surface of particulate matter (PM), there are several alternative pathways by which metal homeostasis in the lower respiratory tract can be disrupted following exposure to ambient air pollution particles to affect an oxidative stress. Evidence suggests that disruption in iron homeostasis following exposures to ambient air pollution particles is an initial event in their biological effect. An association between metal equilibrium in the lower respiratory tract and biological effect in the lung could explain the observed differential toxicity of ultrafine, fine, and coarse particles and disparities in host susceptibility.

Long-term effects of ambient air pollution on lung function: a review

Lung function is an important measure of respiratory health and a predictor of cardiorespiratory morbidity and mortality. Over the past 2 decades, more than 50 publications have investigated long-term effects of ambient air pollution on lung function with most finding adverse effects. Several studies have also suggested effects from traffic-related air pollution. There is strong support for air pollution effects on the development of lung function in children and adolescents. It remains unclear whether subjects with slower development of lung function compensate by prolonging the growth phase, or whether they end their development at a lower plateau, thus entering the decline phase with a reduced lung function. In adults, the evidence for long-term air pollution effects is mostly based on cross-sectional comparisons. One recent longitudinal study observed that decreasing pollution attenuated the decline of lung function in adults. Earlier inconclusive cohort studies were based on limited data. There is great diversity in study designs, markers of air pollution, approaches to the measurement of exposure, and choices in lung function measures. These limit the comparability of studies and impede quantitative summaries. New studies should use individual-level exposure assessment to clarify the role of traffic and to preclude potential community-level confounding. Further research is needed on the relevance of specific pollution sources, particularly with regard to susceptible populations and relevant exposure periods throughout life.

Effects of environmental tobacco smoke on respiratory symptoms and pulmonary function

The aim of this study was to examine the effects of environmental tobacco smoke (ETS) on pulmonary function and respiratory symptoms. During periodic medical examination, 392 French nonsmokers responded to an interviewer-administered questionnaire. Then spirometry was performed to assess pulmonary function. All of the subjects were carefully examined by two occupational physicians. ETS exposure at the workplace was more common than this exposure at home (20% vs. 5%). ETS exposure was significantly associated with forced vital capacity (FVC; -3.16%; 95% CI: -5.67 to -0.64) and forced expiratory volume in 1s (FEV1; -2.90%; 95% CI: -5.59 to -0.23). Abnormal FVC results were significantly increased in exposed subgroup [odds ratio = 2.71 (95% CI: 1.09 to 6.75)]. We did not find any significant dose-response relationship between ETS exposure and lung function results. The effects of ETS exposure on respiratory symptoms and diseases (asthma, wheezing, chronic bronchitis, and dyspnea) were not significant. Thus, this study showed that there was a significant inverse association between exposure to ETS and pulmonary function. Even pulmonary function results inferior to the lower limit of normal may be possible. A stricter legislation against ETS is proposed.

Passive smoking exposure and risk of COPD among adults in China: the Guangzhou Biobank Cohort Study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality in China, where the population is also exposed to high levels of passive smoking, yet little information exists on the effects of such exposure on COPD. We examined the relation between passive smoking and COPD and respiratory symptoms in an adult Chinese population.

METHODS

We used baseline data from the Guangzhou Biobank Cohort Study. Of 20 430 men and women over the age of 50 recruited in 2003-06, 15,379 never smokers (6497 with valid spirometry) were included in this cross-sectional analysis. We measured passive smoking exposure at home and work by two self-reported measures (density and duration of exposure). Diagnosis of COPD was based on spirometry and defined according to the GOLD guidelines.

FINDINGS

There was an association between risk of COPD and self-reported exposure to passive smoking at home and work (adjusted odds ratio 1.48, 95% CI 1.18-1.85 for high level exposure; equivalent to 40 h a week for more than 5 years). There were significant associations between reported respiratory symptoms and increasing passive smoking exposure (1.16, 1.07-1.25 for any symptom).

INTERPRETATION

Exposure to passive smoking is associated with an increased prevalence of COPD and respiratory symptoms. If this association is causal, we estimate that 1.9 million excess deaths from COPD among never smokers could be attributable to passive smoking in the current population in China. Our findings provide strong evidence for urgent measures against passive smoking in China.

Secondhand smoke exposure, pulmonary function, and cardiovascular mortality

PURPOSE

Cardiovascular disease and obstructive lung disease are leading global causes of death. Despite this, the impact of secondhand smoke (SHS) exposure on pulmonary function and cardiovascular disease remains uncertain. Our goal was to elucidate the association between baseline SHS exposure and the risk of lung function decline and cardiovascular mortality over a period of nearly a decade.

METHODS

We used data from a longitudinal cohort study of 1,057 older adults to study the association between baseline SHS exposure and the risk of lung function decline and cardiovascular mortality. The effect of SHS exposure on cardiovascular mortality may be mediated by its influence on FEV1 and biological processes captured by measurement of FEV1. Alternatively, the effect of SHS may be mediated by baseline cardiovascular disease status, which reflects the combined effects of traditional cardiovascular risk factors. To correctly estimate the effect of SHS and FEV1 on cardiovascular mortality, we used marginal structural models (MSMs) that took into account the mediating effects of FEV1 and baseline cardiovascular disease in the causal pathway.

RESULTS

In longitudinal multivariate analyses, lifetime cumulative home and work SHS exposure were associated with a greater decline of FEV1 (-15 mL/s; 95% CI, -29 to -1.3 mL/s and -41 mL/s; 95% CI, -55 to -28 mL/s per 10-year cumulative exposure, respectively). Lifetime home SHS exposure was associated with a greater risk of cardiovascular mortality in both conventional multivariate analysis (HR, 1.10 per 10 years of exposure; 95% CI, 0.99 to 1.24) and the MSM for FEV1 (HR, 1.06; 95% CI, 0.95 to 1.19) and baseline cardiovascular disease (HR for subjects with no baseline cardiovascular disease, 1.39; 95% CI, 1.17 to 1.66).

CONCLUSIONS

Lifetime SHS exposure appears to result in a greater decline in lung function and risk of cardiovascular mortality, taking into account confounders and the mediating effect of FEV1 and baseline cardiovascular disease.

Respiratory effects of environmental tobacco exposure are enhanced by bronchial hyperreactivity

RATIONALE

Exposure to environmental tobacco smoke (ETS) is associated with increased reports of respiratory symptoms and reduced lung function, but the long-term effects of ETS are unclear, notably in healthy individuals with bronchial hyperresponsiveness (BHR).

OBJECTIVE

To assess the longitudinal effects of ETS exposure on the development of respiratory symptoms and spirometry in subjects with BHR.

METHODS

The study population included 1,661 never-smokers from the SAPALDIA (Swiss Study on Air Pollution and Lung Diseases in Adults) cohort, assessed in 1991 (baseline) and 11 yr later, who were symptom-free at baseline. Incident reports of respiratory symptoms and results of spirometry were assessed at the follow-up survey.

MAIN RESULTS

Exposure to ETS reported in the two surveys was strongly associated with the development of cough (odds ratio, 2.1; 95% confidence interval, 1.2-3.7; p = 0.01). In subjects with BHR exposed to ETS at both surveys, a trend for strong associations were observed for wheeze, cough, dyspnea, and chronic bronchitis; however, the association reached statistical significance only for the symptom of dyspnea (p < 0.01). Lower FEV1/FVC (mean +/- SD, 72.9 +/- 7.7 vs. 76.8 +/- 6.1%; p < 0.01) and FEF(25-75) (forced expiratory flow, midexpiratory phase)/FVC (mean +/- SD, 56.1 +/- 22.5 vs. 68.1 +/- 21.6%; p < 0.01) were observed in subjects with BHR exposed to ETS compared with nonexposed subjects without BHR. Lower values were found in subjects continuing exposure by the follow-up survey.

CONCLUSION

Exposure to ETS was strongly associated with the development of respiratory symptoms in previously asymptomatic subjects with BHR within 11 yr. Furthermore, subjects with underlying BHR had reduced lung function at follow-up, thus suggesting a higher risk for the development of chronic respiratory disease in this subset of the population.

Relationship of pulmonary function among women and children to indoor air pollution from biomass use in rural Ecuador

Approximately half the world uses biomass fuel for domestic energy, resulting in widespread exposure to indoor air pollution (IAP) from biomass smoke. IAP has been associated with many respiratory diseases, though it is not clear what relationship exists between biomass use and pulmonary function. Four groups containing 20 households each were selected in Santa Ana, Ecuador based on the relative amount of liquid petroleum gas and biomass fuel that they used for cooking. Pulmonary function tests were conducted on each available member of the households 7 years of age. The pulmonary functions of both children (7-15 years) and women (16 years) were then compared between cooking fuel categories using multivariate linear regression, controlling for the effects of age, gender, height, and exposure to tobacco smoke. Among the 80 households, 77 children and 91 women performed acceptable and reproducible spirometry. In multivariate analysis, children living in homes that use biomass fuel and children exposed to environmental tobacco smoke had lower forced vital capacity and lower forced expiratory volume in 1s (P<0.05). However, no significant difference in pulmonary function was observed among women in different cooking categories. Results of this study demonstrate the harmful effects of IAP from biomass smoke on the lung function of children and emphasize the need for public health efforts to decrease exposure to biomass smoke.

Cross shift changes in lung function among bar and restaurant workers before and after implementation of a smoking ban

OBJECTIVE

To study possible cross shift effects of environmental tobacco smoke (ETS) on pulmonary function among bar and restaurant employees before and after the implementation of a smoking ban in Norway.

METHODS

The study included 93 subjects employed in 13 different establishments in Oslo. They were examined at the beginning and end of a workshift both while ETS exposure was present and when smoking was banned. The mean exposure level of nicotine and total dust before the ban was 28 microg/m3 (range 3-65) and 275 microg/m3 (range 81-506), respectively. Following the smoking ban, the mean level of nicotine and total dust was 0.6 mug/m3 and 77 microg/m3, respectively. Assessment of lung function included dynamic lung volumes and flows.

RESULTS

The cross shift reduction in forced vital capacity (FVC) among 69 subjects participating in both examinations changed from 81 ml (SD 136) during exposure to ETS to 52 ml (SD 156) (p = 0.24) following the smoking ban. The reduction in forced expired volume in one second (FEV1) during a workshift, was borderline significantly reduced when comparing the situation before and after the intervention, by 89 ml (SD = 132) compared to 46 ml (SD = 152) (p = 0.09), respectively. The reduction in forced mid-expiratory flow rate (FEF25-75%) changed significantly from 199 ml/s (SD = 372) to 64 ml/s (SD = 307) (p = 0.01). Among 26 non-smokers and 11 asthmatics, the reduction in FEV1 and FEF25-75% was significantly larger during ETS exposure compared to after the smoking ban. There was an association between the dust concentration and decrease in FEF25-75% before the ban among non-smokers (p = 0.048).

CONCLUSIONS

This first study of cross shift changes before and after the implementation of a smoking ban in restaurants and bars shows a larger cross shift decrease in lung function before compared with after the implementation of the ban.

Airway disease risk from environmental tobacco smoke among coffeehouse workers in Turkey

OBJECTIVES

To examine the effect of ETS exposure on respiratory symptoms and pulmonary function and to compare workers in coffeehouses to those in other occupations in order to assess the risk of respiratory illness in this occupation.

DESIGN

Cross sectional study.

SETTING

The study area consisted of the three metropolitan districts of the city of Izmir, Turkey. 86 coffeehouses and 80 other small scale shops which had no known respiratory risk factor, located in the same area, were taken as the study group.

SUBJECTS

207 workers were assessed.

MAIN OUTCOME MEASUREMENTS

Subjects answered a questionnaire about demographic and working characteristics, respiratory symptoms, and smoking behaviour. Physical examinations and spirometric measurements were carried out at the workplaces.

RESULTS

There was a significant increase in respiratory symptoms in coffeehouse workers. Working in a coffeehouse showed a significant risk for chronic bronchitis (odds ratio (OR) 4.3). In coffeehouse workers, forced expiratory volume in one second (FEV(1)) decreased 5.1%, forced vital capacity (FVC) 3.4%, FEV(1)/FVC 1.6%, peak expiratory flow (PEF) 6.45%, and forced expiratory flow (FEF(25)) 7.2%, FEF(50) 10%, and FEF(25-75) 9.8%. Among workers who were described as having an "airway disease", coffeehouse workers were significantly greater in number. When age, body mass index, and smoking behaviour were controlled, working in a coffeehouse was strongly associated with "airway disease" compared to other workers (OR 5.35, 95% confidence interval 2.41 to 11.87).

CONCLUSIONS

Workers in coffeehouses showed significant increases in respiratory symptoms and decreased pulmonary function. All workers need to gain an awareness of these occupational risks and working conditions should be improved immediately.

Extent of exposure to environmental tobacco smoke (ETS) and its dose-response relation to respiratory health among adults

Background

There is a dearth of standardized studies examining exposure to environmental tobacco smoke (ETS) and its relationship to respiratory health among adults in developing countries.

Methods

In 2004, the Syrian Center for Tobacco Studies (SCTS) conducted a population-based survey using stratified cluster sampling to look at issues related to environmental health of adults aged 18–65 years in Aleppo (2,500,000 inhabitants). Exposure to ETS was assessed from multiple self-reported indices combined into a composite score (maximum 22), while outcomes included both self-report (symptoms/diagnosis of asthma, bronchitis, and hay fever), and objective indices (spirometric assessment of FEV₁ and FVC). Logistic and linear regression analyses were conducted to study the relation between ETS score and studied outcomes, whereby categorical (tertiles) and continuous scores were used respectively, to evaluate the association between ETS exposure and respiratory health, and explore the dose-response relationship of the association.

Results

Of 2038 participants, 1118 were current non-smokers with breath CO levels ≤ 10 ppm (27.1% men, mean age 34.7 years) and were included in the current analysis. The vast majority of study participants were exposed to ETS, whereby only 3.6% had ETS score levels ≤ 2. In general, there was a significant dose-response pattern in the relationship of ETS score with symptoms of asthma, hay fever, and bronchitis, but not with diagnoses of these outcomes. The magnitude of the effect was in the range of twofold increases in the frequency of symptoms reported in the high exposure group compared to the low exposure group. Severity of specific respiratory problems, as indicated by frequency of symptoms and health care utilization for respiratory problems, was not associated with ETS exposure. Exposure to ETS was associated with impaired lung function, indicative of airflow limitation, among women only.

Conclusions

This study provides evidence for the alarming extent of exposure to ETS among adult non-smokers in Syria, and its dose-response relationship with respiratory symptoms of infectious and non-infectious nature. It calls for concerted efforts to increase awareness of this public health problem and to enforce regulations aimed at protecting non-smokers.

Predictors of smoke-free workplaces by employee characteristics: who is left unprotected?

BACKGROUND

Over the last decade, there has been steady progress in the adoption of workplace smoking policies in the United States. However, the benefits of a smoke-free workplace are not distributed equally among the workforce.

METHODS

Data from 44,357 adults who reported that they work indoors were derived from an optional tobacco module on the 2001 Behavioral Risk Factor Surveillance System (BRFSS), administered by 25 states. Logistic regression was utilized to examine factors associated with the absence of a smoke-free workplace policy.

RESULTS

Overall, 70.9% of respondents reported working under a smoke-free workplace policy. The likelihood of being protected by a smoke-free workplace policy was significantly lower among workers who were younger, male, non-white, engaged in heavy labor, earned less than 50,000 US dollars annually, had a high school education or less, smoked everyday, or worked in the South or Midwest.

CONCLUSIONS

There remain considerable gaps in smoke-free workplace policy coverage.

Environmental tobacco smoke exposure and pulmonary function among adults in NHANES III: impact on the general population and adults with current asthma

The impact of environmental tobacco smoke (ETS) exposure on adult pulmonary function has not been clearly determined. Because adults with asthma have chronic airway inflammation, they may be a particularly susceptible group. Using data from the Third National Health and Nutrition Examination Survey (NHANES III), I examined the cross-sectional relationship between serum cotinine, a biomarker of ETS exposure, and pulmonary function among 10,581 adult nonsmokers and 440 nonsmoking adults with asthma whose cotinine and spirometry data were available. I generated residuals, which are observed minus predicted values (based on Crapo equations), for forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio to adjust for age, sex, and height. In addition, I used multivariate linear regression to control for sociodemographic characteristics and previous smoking history. Most adults with and without asthma had detectable serum cotinine levels, indicating recent ETS exposure (85.7% and 83.4%, respectively). Among nonsmoking male participants, I found no evidence that ETS exposure was related to decreased pulmonary function. In the nonsmoking female stratum, the highest cotinine tertile was associated with a lower FEV1 [-100 mL; 95% confidence interval (CI), -143 to -56 mL], FVC (-119 mL; 95% CI, -168 to -69 mL), and FEV1/FVC ratio (-1.77%; 95% CI, -2.18% to -1.36%). Among women with asthma, the highest cotinine tertile was also associated with decreased FEV1 (-261 mL; 95% CI, -492 to -30 mL), FVC (-291 mL; 95% CI, -601 to 20 mL), and FEV1/FVC ratio (-1.6%; 95% CI, -3.3% to 0.19%). In conclusion, ETS exposure is associated with decreased pulmonary function in adult females, especially those with asthma. This analysis should provide further impetus for public policies that promote smoke-free environments.

Review: occupational and environmental lung disease

Occupational and environmental lung disease is a vast topic. Therefore, this review focuses on areas that represent new clinical insights that have not been addressed recently in Current Opinion in Pulmonary Medicine. The topics are considered important for the future and emphasize diseases that strike large numbers of people or exposures that affect large segments of the population. This review highlights literature published between the years 2000 to 2001 related to air pollution, occupational asthma, lung diseases in agricultural workers, nylon flock workers lung disease, pneumoconiosis, and environmental exposure to biomass smoke, including environmental tobacco smoke. These publications highlight the changing world of occupational and environmental lung diseases. Traditionally, this field dealt with chronic diseases caused by very high levels of exposure to materials that affected virtually all workers to a similar degree. Disease could be recognized readily by characteristic symptoms, signs, and radiographic abnormalities. Dose-effect relationships were usually clear, and the solution to disease was generally to limit exposure for all workers. This approach served well for conditions such as coal workers pneumoconiosis or toxic responses to chlorine gas. The new world of occupational and environmental lung diseases often involves low levels of exposure to complex mixtures of materials that produce nonspecific or intermittent symptoms in a subgroup of exposed individuals. Interactions between genetic susceptibility, concomitant tobacco smoke exposure, and co-morbid diseases hugely complicate both diagnosis and prevention. New tools, and possibly new thought paradigms, are needed to detect, treat, and prevent occupational and environmental lung diseases in a changing world.