Environmental tobacco smoke and adult asthma

An Exploration of Features Impacting Respiratory Diseases in Urban Areas

Air pollution exposure has become ubiquitous and is increasingly detrimental to human health. Small Particulate matter (PM) is one of the most harmful forms of air pollution. It can easily infiltrate the lungs and trigger several respiratory diseases, especially in vulnerable populations such as children and elderly people. In this work, we start by leveraging a retrospective study of 416 children suffering from respiratory diseases. The study revealed that asthma prevalence was the most common among several respiratory diseases, and that most patients suffering from those diseases live in areas of high traffic, noise, and greenness. This paved the way to the construction of the MOREAIR dataset by combining feature abstraction and micro-level scale data collection. Unlike existing data sets, MOREAIR is rich in context-specific components, as it includes 52 temporal or geographical features, in addition to air-quality measurements. The use of Random Forest uncovered the most important features for the understanding of air-quality distribution in Moroccan urban areas. By linking the medical data and the MOREAIR dataset, we observed that the patients included in the medical study come mostly from neighborhoods that are characterized by either high average or high variations of pollution levels.

Cigarette Smoke Particle-Induced Lung Injury and Iron Homeostasis

It is proposed that the mechanistic basis for non-neoplastic lung injury with cigarette smoking is a disruption of iron homeostasis in cells after exposure to cigarette smoke particle (CSP). Following the complexation and sequestration of intracellular iron by CSP, the host response (eg, inflammation, mucus production, and fibrosis) attempts to reverse a functional metal deficiency. Clinical manifestations of this response can present as respiratory bronchiolitis, desquamative interstitial pneumonitis, pulmonary Langerhans’ cell histiocytosis, asthma, pulmonary hypertension, chronic bronchitis, and pulmonary fibrosis. If the response is unsuccessful, the functional deficiency of iron progresses to irreversible cell death evident in emphysema and bronchiectasis. The subsequent clinical and pathological presentation is a continuum of lung injuries, which overlap and coexist with one another. Designating these non-neoplastic lung injuries after smoking as distinct disease processes fails to recognize shared relationships to each other and ultimately to CSP, as well as the common mechanistic pathway (ie, disruption of iron homeostasis).

Mechanisms of Immunotoxicity: Stressors and Evaluators

The immune system defends the body against certain tumor cells and against foreign agents such as fungi, parasites, bacteria, and viruses. One of its main roles is to distinguish endogenous components from non-self-components. An unproperly functioning immune system is prone to primary immune deficiencies caused by either primary immune deficiencies such as genetic defects or secondary immune deficiencies such as physical, chemical, and in some instances, psychological stressors. In the manuscript, we will provide a brief overview of the immune system and immunotoxicology. We will also describe the biochemical mechanisms of immunotoxicants and how to evaluate immunotoxicity.

Acute Exposure to Environmental Tobacco Smoke: A Controlled Study in Adults with Asthma

BACKGROUND

Short-term, indoor exposure to environmental tobacco smoke (ETS) is still highly prevalent; however, little is known about the acute lung response in adult asthma.

OBJECTIVES

We investigated whether acute, experimental ETS exposure influences symptoms, lung function, and inflammatory parameters.

METHODS

Human subjects with asthma (n = 23) were exposed for 180 min to either room air or ETS at 250, 450, or 850 µg/m3. Respiratory symptoms, lung function, and exhaled nitric oxide (FeNO) were measured. Additionally, blood samples were analyzed for pro- and anti-inflammatory cytokines.

RESULTS

Humans with asthma demonstrate an increase in respiratory symptoms at all levels of ETS exposure, while the forced expiratory volume in 1 s (FEV1) and FeNO decrease with increasing ETS. The anti-inflammatory cytokine interleukin (IL)-10 increases at intermediate ETS concentrations, whereas tumor necrosis factor (TNF)-α and IL-8 increase only at the highest ETS concentration.

CONCLUSION

Following 180 min of acute, experimental ETS exposure, we observed a significant increase in respiratory symptoms, a decrease in lung function, and an increase in inflammatory cytokines, indicating an acute lung response in asthma.

Inhaled medication usage in post-menopausal women and lifetime tobacco smoke exposure: The Women's Health Initiative Observational Study

OBJECTIVE

While active smoking is a causal agent in respiratory disease, the independent role of secondhand smoke (SHS) merits further investigation. We investigated associations between lifetime active smoking and exposure to secondhand smoke - studied independently - and current use of 1 or more inhaled medications as a surrogate for prevalent pulmonary disease in post-menopausal women.

STUDY DESIGN

Information on lifetime active and passive tobacco exposure and inhaled pulmonary medication usage at enrollment was collected from 88,185 postmenopausal women aged 50-79 enrolled in the Women's Health Initiative Observational Study from 1993 to 1998 at 40 centers in the United States. Participants were recruited from localities surrounding the study centers using a variety of methods, including informational mailings and mass media campaigns.

MAIN OUTCOME MEASURES

Multivariate adjusted regression models were used to estimate odds ratios and 95% CI according to levels of active smoking and SHS exposure, and trends were tested across categories.

RESULTS

Ever active smokers had an overall OR of 1.97 (95% CI 1.58-2.45) for having one or more prescribed inhaled medication compared with never-smoking women not exposed to active or passive smoke. The overall OR for using inhalers for never-smoking women exposed to any SHS compared with the same reference group was 1.33 (95% CI 1.07-1.65). In a quantified analysis of SHS, never-smoking women with the highest levels of lifetime SHS exposure had an estimated risk of inhaled medication usage of 1.74 (95% CI 1.32-2.30).

CONCLUSIONS

The risk of requiring one or more prescribed inhaled medications for pulmonary disease was significantly higher in post-menopausal women who ever smoked or who had lifetime exposure to SHS.

Exposure to environmental tobacco smoke induces angiogenesis and leukocyte trafficking in lung microvessels

Exposure to environmental tobacco smoke (ETS) is known to contribute to and exacerbate inflammatory diseases of the lung such as chronic obstructive pulmonary disease (COPD) and asthma. The effect of ETS on angiogenesis and leukocyte recruitment, both of which promote lung inflammation, was investigated using lung tissue from mice exposed to aged and diluted sidestream cigarette smoke or fresh air for 12 weeks and transplanted into dorsal skin-fold chambers in nude mice. Lung tissue from mice exposed to cigarette smoke for 12 weeks exhibited significantly increased vascular density (angiogenesis) associated with selectin-mediated increased intravascular leukocyte rolling and adhesion compared to fresh air-exposed lung tissue by intravital microscopy. Further, neutrophils from nicotine-exposed mice displayed significantly increased rolling and adhesion compared to control neutrophils in microvessels of nicotine-exposed lungs versus control lung microvessels, suggesting that nicotine in cigarette smoke can augment leukocyte-endothelial interactions. ETS-induced angiogenesis and leukocyte trafficking may play a key role in airway recruitment of inflammatory cells in ETS-associated disorders such as COPD bronchitis or asthma.

Asthma, environmental risk factors, and hypertension among Arab Americans in metro Detroit

Asthma and obesity-related health problems disproportionately impact low-income ethnic minority communities residing in urban areas. Environmental risk factors, particularly those related to housing and indoor air, may impact the development or exacerbation of asthma. There is increasing evidence to suggest a link between obesity-related health problems and asthma. Previous studies have also reported that immigrant status may influence myriad risk factors and health outcomes among immigrant populations. The Arab American Environmental Health Project (AAEHP) was the first study to explore environmental health problems among Arab Americans. This paper examined whether hypertensive status modified the relationship between environmental risk factors and asthma among Arab Americans in metro Detroit. An environmental risk index (ERI) was used to quantify household environmental risk factors associated with asthma. Physician diagnosed hypertension was self-reported, and asthma status was determined using responses to a validated symptoms checklist and self-reported diagnosis by a physician. Hypertension significantly modified the relationship between ERI and asthma in this study population. The positive association between household environmental risk factors and asthma was stronger among participants diagnosed with hypertension. Effect modification of the relationship between environmental risk factors and asthma could have serious implications among high-risk communities. However, further research is needed to elucidate the relationships between hypertension, environmental risk factors, and asthma.

Reduction in asthma-related emergency department visits after implementation of a smoke-free law

BACKGROUND

Secondhand tobacco smoke increases the risk for the development and increasing severity of asthma among adults and children. Reducing exposure to secondhand smoke decreases symptomatic exacerbations among patients with asthma. Emergency department (ED) visits for asthma were assessed before and after the implementation of smoke-free legislation in Lexington-Fayette County, Ky.

OBJECTIVE

To evaluate the effects of a smoke-free law on the rate of ED visits for asthma.

METHODS

The study included ED visits for asthma from 4 hospitals in Lexington-Fayette County, Ky. Age-adjusted rates of asthma ED visits were determined. Poisson regression analysis of ED visits from January 1, 2001, to December 31, 2006 compared the ED visit rates between prelaw and postlaw, adjusting for seasonality, secular trends over time, and differences among demographic subgroups. The actual rates were graphed with the Poisson curve showing the rates predicted by the model. A second prediction curve was generated to show the projected rates in the postlaw period if the law had not been implemented.

RESULTS

Adjusting for seasonality, secular trends, and demographic characteristics, ED visits for asthma declined 22% from prelaw to postlaw (P < .0001; 95% CI, 14% to 29%). The rate of decline was 24% in adults age 20 years and older (P < .0001), whereas the decrease among children 19 years or younger was 18% (P = .01).

CONCLUSION

Although this study did not establish causation, the smoke-free law was associated with fewer asthma ED visits among both children and adults, with a more significant decline among adults.

In vivo gamma-tocopherol supplementation decreases systemic oxidative stress and cytokine responses of human monocytes in normal and asthmatic subjects

We have recently reported that gamma-tocopherol (gammaT) reduces allergen- and zymosan-induced inflammation using rodent models. As an initial step in extending these observations to humans, we conducted an open-label, Phase I dosing study of two doses (one or two capsules daily for 1 week) of a gamma-tocopherol-rich preparation containing 623 mg of gamma-tocopherol, 61.1 mg of d-alpha-tocopherol, 11.1 mg of d-beta-tocopherol (11.1 mg), and 231 mg of d-sigma-tocopherol per capsule. Endpoints for this study include serum levels of 5-nitro-gamma-tocopherol, as a marker of oxidative stress, and changes in serum gamma-, alpha-, and delta-tocopherol and gamma-2'-carboxyethyl-6-hydroxychroman (CEHC) 6 and 24 h after the first dose and after 1 week of treatment. To assess the biological activity of this treatment, we obtained peripheral blood mononuclear cells at baseline and after 1 week of treatment with two capsules of a gamma-tocopherol-rich preparation/day and examined the inflammatory cytokine response of these cells in culture to ex vivo endotoxin/LPS (0.01 ng/ml) challenge. We also monitored a number of safety endpoints to examine how well this preparation is tolerated in eight normal volunteers (four allergic and four nonallergic) and eight allergic asthmatics. We further obtained human monocytes from a subset of these volunteers and treated them ex vivo with gammaT, alphaT, gamma-CEHC, and alpha-CEHC and assessed their actions on LPS-induced degradation of IkappaBalpha and JNK signaling and ROS generation. As detailed herein, this open-label study demonstrates that gamma-tocopherol-enriched supplementation decreased systemic oxidative stress, increased serum levels of gamma-tocopherol, and inhibited monocyte responses to LPS without any adverse health effects. Further, in vitro treatment of human monocytes with gamma-CEHC and alpha-CEHC inhibits ROS generation and LPS-induced degradation of IkappaB and JNK activation.

High-dose but not low-dose mainstream cigarette smoke suppresses allergic airway inflammation by inhibiting T cell function

Epidemiological studies have identified childhood exposure to environmental tobacco smoke as a significant risk factor for the onset and exacerbation of asthma, but studies of smoking in adults are less conclusive, and mainstream cigarette smoke (MCS) has been reported to both enhance and attenuate allergic airway inflammation in animal models. We sensitized mice to ovalbumin (OVA) and exposed them to MCS in a well-characterized exposure system. Exposure to MCS (600 mg/m(3) total suspended particulates, TSP) for 1 h/day suppresses the allergic airway response, with reductions in eosinophilia, tissue inflammation, goblet cell metaplasia, IL-4 and IL-5 in bronchoalveolar lavage (BAL) fluid, and OVA-specific antibodies. Suppression is associated with a loss of antigen-specific proliferation and cytokine production by T cells. However, exposure to a lower dose of MCS (77 mg/m(3) TSP) had no effect on the number of BAL eosinophils or OVA-specific antibodies. This is the first report to demonstrate, using identical smoking methodologies, that MCS inhibits immune responses in a dose-dependent manner and may explain the observation that, although smoking provokes a systemic inflammatory response, it also inhibits T cell-mediated responses involved in a number of diseases.

Exposure to secondhand smoke at work: a survey of members of the Australian Liquor, Hospitality and Miscellaneous Workers Union

OBJECTIVE

To measure workers' attitudes towards and experiences of exposure to secondhand smoke (SHS) in the workplace.

METHOD

A stratified random sample of members from the Victorian Branch of the Australian Liquor, Hospitality and Miscellaneous Workers Union (LHMU) was interviewed by telephone in September 2001. Of the 1,078 respondents surveyed (77% response rate), hospitality workers comprised 49% of the sample, while the remainder comprised community services, property services and manufacturing workers.

RESULTS

Overall, 54% of union members were employed in workplaces that did not completely ban smoking and 34% reported being exposed to SHS during their typical working day. Workplaces with total smoking bans had a high level of compliance with these restrictions, with no workers in these settings indicating exposure to SHS at work. Compared with other workers, hospitality workers reported working in environments that had more permissive smoking policies. Consistent with this, 56% of hospitality workers said they were exposed to SHS during a typical day at work compared with 11% of other workers. Overall, 79% of workers expressed concern about exposure to SHS, including 66% of smokers. Compared with other workers, hospitality workers reported a higher level of concern about exposure to SHS at work.

CONCLUSION

These findings provide evidence that many workers, and especially those employed in the hospitality sector, are exposed to SHS during their working day and are concerned about the effects of such exposure on their health.

IMPLICATIONS

These findings indicate that workplace smoke-free policies are effective in reducing worker exposure to SHS and demonstrate support for the extension of smoke-free policies to hospitality workplaces.

The role of environmental tobacco smoke in the origins and progression of asthma

Exposure to environmental tobacco smoke (ETS) is a major source of indoor air pollution and causes adverse effects on the respiratory health of individuals with asthma. At least one third of children and adults with asthma are exposed to ETS on a regular basis. There is convincing evidence for a causal relationship between exposure to ETS and development of asthma in children and in nonsmoking adults. Exposure to ETS also worsens asthma control in children and nonsmoking adults who have established asthma. The mechanism by which ETS causes these harmful effects is not established but may involve genetic predisposition, impairment of lung development, and altered lung inflammatory responses. Workplace smoking restrictions and reduced smoking in the home may lower the prevalence of asthma, improve asthma control, and reduce the use of medical services in both children and adults who are exposed to ETS.

Primary care affiliations of adults in a methadone program with onsite care

Methadone maintenance treatment programs (MMTP) often provide onsite primary care. It is unclear whether patients in these settings consider the MMTP their usual source of care. We conducted cross-sectional interviews of 62 adults in an inner-city MMTP with onsite primary care to determine their usual source of care. Program enrollment ranged from 1 to 27 years (median, 4) and 63% attended > or = 5 days per week. Seventy-six percent had > or = 1 chronic disease. Only 53% reported having a usual source of care, which included hospital-based clinics (45%), the MMTP (23%), private physicians (19%), other sites (13%). Patients were more likely to identify the MMTP as their usual source of care if they had cardiovascular disease (RR 6.9, 95% CI 2.2 to 21.9) or HIV (RR 5.6, 95% CI 1.7 to 18.5). Successfully promoting appropriate utilization of onsite primary care may require a better understanding of MMTP patients' perceptions of primary care.

Catalase overexpression fails to attenuate allergic airways disease in the mouse

Oxidative stress is a hallmark of asthma, and increased levels of oxidants are considered markers of the inflammatory process. Most studies to date addressing the role of oxidants in the etiology of asthma were based on the therapeutic administration of low m.w. antioxidants or antioxidant mimetic compounds. To directly address the function of endogenous hydrogen peroxide in the pathophysiology of allergic airway disease, we comparatively evaluated mice systemically overexpressing catalase, a major antioxidant enzyme that detoxifies hydrogen peroxide, and C57BL/6 strain matched controls in the OVA model of allergic airways disease. Catalase transgenic mice had 8-fold increases in catalase activity in lung tissue, and had lowered DCF oxidation in tracheal epithelial cells, compared with C57BL/6 controls. Despite these differences, both strains showed similar increases in OVA-specific IgE, IgG1, and IgG2a levels, comparable airway and tissue inflammation, and identical increases in procollagen 1 mRNA expression, following sensitization and challenge with OVA. Unexpectedly, mRNA expression of MUC5AC and CLCA3 genes were enhanced in catalase transgenic mice, compared with C57BL/6 mice subjected to Ag. Furthermore, when compared with control mice, catalase overexpression increased airway hyperresponsiveness to methacholine both in naive mice as well as in response to Ag. In contrast to the prevailing notion that hydrogen peroxide is positively associated with the etiology of allergic airways disease, the current findings suggest that endogenous hydrogen peroxide serves a role in suppressing both mucus production and airway hyperresponsiveness.

Asthma control or severity: that is the question

In the first National Heart Lung and Blood Institute and Global Initiative for Asthma (GINA) guidelines, the level of symptoms and airflow limitation and its variability allowed asthma to be subdivided by severity into four subcategories (intermittent, mild persistent, moderate persistent, and severe persistent). It is important to recognize, however, that asthma severity involves both the severity of the underlying disease and its responsiveness to treatment. Thus, the first update of the GINA guidelines defined asthma severity depending on the clinical features already proposed as well as the current treatment of the patient. In addition, severity is not a fixed feature of asthma, but may change over months or years, whereas the classification by severity suggests a static feature. Moreover, using severity as an outcome measure has limited value in predicting what treatment will be required and what the response to that treatment might be. Because of these considerations, the classification of asthma severity is no longer recommended as the basis for treatment decisions, a periodic assessment of asthma control being more relevant and useful.

Cancer incidence in a general population of asthma patients

PURPOSE

Several studies have assessed the association between asthma and cancer but none of them revealed a clear pattern of association. We aimed to examine the association between asthma, chronic obstructive pulmonary disease (COPD), and cancer.

METHODS

We performed a cohort study with a nested case-control analysis using the General Practitioner Research Database in the UK. We defined three cohorts: patients with asthma, patients with COPD, and general population. During the follow-up, we identified a total of 5263 incident cases of cancer. We conducted a nested case-control analysis that included all cancer cases as well as 20 000 controls free of cancer frequency-matched on age, sex, and calendar year.

RESULTS

Patients with asthma did not have an overall greater risk of cancer compared with the general population (odds ratio = 0.93, 95% confidence interval (CI): 0.86-1.00). However, they presented an elevated risk of experiencing lung cancer (odds ratio = 1.84, 95%CI: 1.58-2.15). Controlling for smoking and other potential confounding factors yielded a lower estimate (odds ratio = 1.35, 95%CI: 1.15-1.59). This estimate contrasted with that observed for non-smoking related cancer (0.87, 95%CI: 0.80-0.94). Overall, respiratory drugs did not seem to be associated with cancer among asthmatic patients. Patients with COPD had an Odds ratio of cancer of 1.26 (95%CI: 1.12-1.43) compared with the general population.

CONCLUSIONS

Asthma was not associated with an increased risk of cancer. In fact, the risk of non-smoking related cancer was slightly reduced. However, we observed a small-elevated risk of lung cancer among asthmatic patients. Whether this result is a due to residual confounding and/or protopathic bias remains unclear. Further investigation is warranted to confirm or discard these associations.

Smoking intensity, duration, and cessation, and the risk of rheumatoid arthritis in women

BACKGROUND

Cigarette smoking has been associated with rheumatoid arthritis (RA), but the importance of smoking intensity, duration, and time since quitting, and whether the risk is primarily for rheumatoid factor (RF) seropositive versus seronegative RA are still unclear.

METHODS

We conducted a prospective analysis of smoking and the risk of RA among 103,818 women in the Nurses' Health Study. A total of 680 RA cases, diagnosed from 1976 and 2002, were confirmed using a questionnaire and medical record review. Sixty percent were RF positive. Cox proportional hazards models calculated the relative risks (RRs) of RA with smoking, adjusting for reproductive and lifestyle factors.

RESULTS

The RR of RA was significantly elevated among current (RR 1.43 [95% confidence interval 1.16-1.75]) and past smokers (RR 1.47 [95% confidence interval 1.23-1.76]), compared with never smokers. The risk of RA was significantly elevated with 10 pack-years or more of smoking and increased linearly with increasing pack-years (P trend <.01). A greater number of daily cigarettes and longer duration of smoking were associated with increased risk. The effect of smoking was much stronger among RF-positive cases than among RF-negative cases. The risk remained elevated in past smokers until 20 years or more after cessation.

CONCLUSIONS

In this large cohort, past and current cigarette smoking were related to the development of RA, in particular seropositive RA. Both smoking intensity and duration were directly related to risk, with prolonged increased risk after cessation.

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.

Lifetime environmental tobacco smoke exposure and the risk of chronic obstructive pulmonary disease

BACKGROUND

Exposure to environmental tobacco smoke (ETS), which contains potent respiratory irritants, may lead to chronic airway inflammation and obstruction. Although ETS exposure appears to cause asthma in children and adults, its role in causing COPD has received limited attention in epidemiologic studies.

METHODS

Using data from a population-based sample of 2,113 U.S. adults aged 55 to 75 years, we examined the association between lifetime ETS exposure and the risk of developing COPD. Participants were recruited from all 48 contiguous U.S. states by random digit dialing. Lifetime ETS exposure was ascertained by structured telephone interview. We used a standard epidemiologic approach to define COPD based on a self-reported physician diagnosis of chronic bronchitis, emphysema, or COPD.

RESULTS

Higher cumulative lifetime home and work exposure were associated with a greater risk of COPD. The highest quartile of lifetime home ETS exposure was associated with a greater risk of COPD, controlling for age, sex, race, personal smoking history, educational attainment, marital status, and occupational exposure to vapors, gas, dusts, or fumes during the longest held job (OR 1.55; 95% CI 1.09 to 2.21). The highest quartile of lifetime workplace ETS exposure was also related to a greater risk of COPD (OR 1.36; 95% CI 1.002 to 1.84). The population attributable fraction was 11% for the highest quartile of home ETS exposure and 7% for work exposure.

CONCLUSION

ETS exposure may be an important cause of COPD. Consequently, public policies aimed at preventing public smoking may reduce the burden of COPD-related death and disability, both by reducing direct smoking and ETS exposure.

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.

Housing and public health

This review considers the broad area of housing and public health, one of the traditional and core areas of public health research and intervention. The review takes into account the range of factors, acting at different levels, directly and indirectly, through which housing affects health. In public health terms, housing affects health in a myriad of relatively minor ways, in total forming one of the key social determinants of health. The paper closes by considering how the improvement of housing and neighborhoods has been a core activity of public health and a central component in tackling poverty. Investment in housing can be more than an investment in bricks and mortar: It can also form a foundation for the future health and well-being of the population. Addressing poor-quality housing and detrimental neighborhoods, in the broadest sense, is thus a task that should be grasped with vigor and determination by all those involved in public health.

Influence of smoking on predictors of vascular disease

Beyond the already well-established strong causative relationship with cancer, smoking increases the risk for vascular disease. Smoking may act directly or adversely influence risk factors contributing to the development of vascular disease. Smoking causes endothelial dysfunction, dyslipidemia (decreased high-density lipoprotein cholesterol levels, hypertriglyceridemia and increased oxidation of low-density lipoprotein cholesterol) and platelet activation leading to a prothrombotic state. Smoking increases emerging risk factors (eg, fibrinogen, homocysteine, and high-sensitivity C-reactive protein) and increases insulin resistance and the risk of developing type 2 diabetes mellitus. The beneficial effects of statins and antioxidants (eg, vitamins C and E, beta-carotene) are counteracted by smoking. Smoking-induced alterations in growth factors, adhesion molecules, and even in genes can accelerate the progression of atherosclerosis. The aim of this review is to consider the adverse consequences of smoking on the factors predisposing to vascular disease and to emphasize the beneficial effects of smoking cessation.