BackgroundOccupational risk factors are one of the major causes of respiratory illnesses and symptoms, and account for 13% of chronic obstructive pulmonary disease and 11% of asthma worldwide. Majority of brick kilns in Pakistan use wood and coal for baking the bricks which makes the brick kiln workers susceptible to high exposure of air pollution. This study was designed to describe frequency of chronic respiratory symptoms and illnesses and study the association between these symptoms and different types of work.MethodsThis was a questionnaire based cross sectional survey conducted among the brick kiln workers in Larkana and Dadu districts, Sindh, Pakistan. A total of 340 adult men were assessed using translated version of the American Thoracic Society Division of Lung Disease (ATS-DLD) questionnaire. Logistic regression analysis was done to determine the relationship between various socio-demographic and occupational factors (age, education, type of work, number of years at work, smoking status), and the respiratory symptoms and illnesses (chronic cough, chronic phlegm, wheeze, Chronic Bronchitis and asthma).ResultsResults of the study show that 22.4% workers had chronic cough while 21.2% reported chronic phlegm. 13.8% had two or more attacks of shortness of breath with wheezing. 17.1% workers were suffering from Chronic Bronchitis while 8.2% reported physician diagnosed asthma. Amongst the non-smoking workers 8.9% had Chronic Bronchitis. Multivariate analysis found that workers involved in brick baking were more likely to have Chronic Bronchitis (OR= 3.7, 95% CI 1.1-11.6, p=<0.05) and asthma (OR= 3.9, 95% CI 1.01-15.5, p=<0.05) compared to those involved in carriage and placement work.ConclusionA high frequency of respiratory symptoms and illnesses was observed among brick kiln workers. Age, nature of work and smoking were strong predictors of developing these symptoms and illnesses.

This study highlights the burden of respiratory illnesses and symptoms, and a low prevalence of asthma among textile workers in Karachi. Work in the spinning section, lack of education, prolonged duration of work and Sindhi ethnicity, were identified as important risk factors.

Rationale: The Global Burden of Disease program identified smoking and ambient and household air pollution as the main drivers of death and disability from chronic obstructive pulmonary disease (COPD).Objectives: To estimate the attributable risk of chronic airflow obstruction (CAO), a quantifiable characteristic of COPD, due to several risk factors.Methods: The Burden of Obstructive Lung Disease study is a crosssectional study of adults, aged $40, in a globally distributed sample of 41 urban and rural sites. Based on data from 28,459 participants, we estimated the prevalence of CAO, defined as a postbronchodilator FEV 1 -to-FVC ratio less than the lower limit of normal, and the relative risks associated with different risk factors. Local relative risks were estimated using a Bayesian hierarchical model borrowing information from across sites.From these relative risks and the prevalence of risk factors, we estimated local population attributable risks. Measurements and Main Results:The mean prevalence of CAO was 11.2% in men and 8.6% in women. The mean population attributable risk for smoking was 5.1% in men and 2.2% in women. The next most influential risk factors were poor education levels, working in a dusty job for $10 years, low body mass index, and a history of tuberculosis. The risk of CAO attributable to the different risk factors varied across sites.Conclusions: Although smoking remains the most important risk factor for CAO, in some areas, poor education, low body mass index, and passive smoking are of greater importance. Dusty occupations and tuberculosis are important risk factors at some sites.

Background: Cotton dust exposure among textile mill workers lead to impaired lung function. However, only few studies have investigated the dose-response relationship between cotton dust and lung function.Objective: To determine the dose-response relationship between cotton dust exposure and lung function among textile workers.Methods: This cross-sectional survey was conducted from January to March 2016 and included 303 adult male textile workers from spinning and weaving sections of 5 mills in Karachi, Pakistan. We collected data through a translated version of the American Thoracic Society respiratory questionnaire (ATS-DLD-78A) and using spirometry. Mill-level airborne cotton dust was measured over an 8-12-hour shift through UCB-PATS (University of California, BerkeleyParticle, and Temperature Monitoring System). Multiple linear regression was used to determine the association between cotton dust exposure and lung function assessed through the 3 indices: forced expiratory volume in the first second (FEV 1 ), forced vital capacity (FVC), and their ratio (FEV 1 /FVC). Results:The mean age of the workers was 32.5 (SD 10.5) years. The mean spirometry indices expressed in percent predicted values were FEV 1 82.6 (SD 14.0); FVC 90.3 (14.7), and FEV 1 /FVC 94.9 (10.5). The median cotton dust concentration was 0.61 (IQR 0.2 to 1.3) mg/ m 3 . The frequency of respiratory symptoms was 15% for cough, 20% for phlegm, and 20% for wheezing. After adjustment for covariates, every mg/m 3 increase in dust concentration was associated with 5.4% decline in FEV 1 . Conclusion:This study quantifies the exposure-dependent relationship between cotton dust and lung function; which has implications for regulations and standards in the textile industry in Pakistan and similar cotton-processing countries. Cite this article as: Ali NA, Nafees AA, Fatmi Z, Azam SI. Dose-response of cotton dust exposure with lung function among textile workers: MultiTex study in Karachi, Pakistan. Int J Occup Environ Med 2018;9:120-128. Keywords

BackgroundThis study was conducted in order to determine the prevalence of asthma and associated risk factors in the adult population of Karachi, Pakistan.MethodsThis multi-stage, cross-sectional survey was conducted from May 2014–August 2015; comprising 1629 adults in 75 randomly selected clusters in Karachi, Pakistan. Definitions included: ‘self-reported asthma’, ‘reversibility in FEV1’ and ‘respiratory symptoms and reversibility in FEV1’.ResultsPrevalence of asthma was 1.8% (self-reported) (95% CI: 1.0–2.6), 11.3% (reversibility in FEV1) (95% CI: 9.4–13.3) and 6.6% (symptoms and reversibility in FEV1) (95% CI: 5.1–8.1). Asthmatics were more likely to belong to the age group ≥38 years according to ‘reversibility in FEV1’ and ‘respiratory symptoms and reversibility in FEV1’ (AOR: 1.9, 95% CI: 1.2–3.3) and (AOR: 2.1, 95% CI: 1.1–4.2), respectively. Asthmatics were more likely to report history of allergies (AOR: 1.9, 95% CI: 1.2–2.9) and (AOR: 2.8, 95% CI: 1.7–4.8); and were exposed to environmental tobacco smoke (AOR: 1.6, 95% CI: 1.1–2.5) and (AOR: 1.9, 95% CI: 1.1–3.3) according to ‘reversibility in FEV1’ and ‘respiratory symptoms and reversibility in FEV1’, respectively. Asthmatics were more likely to report pack years of smoking ≥5 (AOR: 2.3, 95% CI: 1.1–4.7) according to ‘respiratory symptoms and reversibility in FEV1’.ConclusionThis study reports a high prevalence of asthma among Pakistani adults and calls for developing appropriate public health policies for prevention and control of asthma in the country. Further studies should be conducted to determine the national prevalence as well as follow-up studies to identify preventable causes for adult asthma.Electronic supplementary materialThe online version of this article (10.1186/s12890-018-0753-y) contains supplementary material, which is available to authorized users.