Research

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

Wasim Maziak^1,5 , Kenneth D Ward^1,2 , Samer Rastam¹ , Fawaz Mzayek³ and Thomas Eissenberg^1,4

¹  Syrian Center for Tobacco Studies, Aleppo, Syria

²  Department of Health & Sport Sciences, and Center for Community Health, University of Memphis, Memphis, USA

³  Department of Epidemiology, Tulane School of Public Health and Tropical Medicine, New Orleans, USA

⁴  Department of Psychology, Virginia Commonwealth University, Richmond, USA

⁵  Institute of Epidemiology & Social Medicine, University of Muenster, Muenster, Germany

author email corresponding author email

Respiratory Research 2005, 6:13doi:10.1186/1465-9921-6-13

Published:	8 February 2005

Abstract

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.