Asaad Ahmed Nafees

Secondhand smoke exposures in indoor public places in seven Asian countries.

Exposure to secondhand smoke (SHS) is a major threat to public health. Asian countries having the highest smoking prevalence are seriously affected by SHS. The objective of the study was to measure SHS levels in hospitality venues in seven Asian countries and to compare the SHS exposure to the levels in Western countries. The study was carried out in four types of related hospitality venues (restaurant, café, bar/club and entertainment) in China, India, Japan, Korea, Malaysia, Pakistan and Sri Lanka. Real-time measurement of particulate matter of <2.5microm aerodynamic diameter (PM(2.5)) was made during business hour using a handheld laser operated monitor. A total of 168 venues were measured in seven countries. The average indoor PM(2.5) level was 137microg/m(3), ranging from 46microg/m(3) in Malaysia to 207microg/m(3) in India. Bar/club had the highest PM(2.5) level of 191microg/m(3) and restaurants had the lowest PM(2.5) level of 92microg/m(3). The average indoor PM(2.5) level in smoking venues was 156micro/m(3), which was 3.6 times higher than non-smoking venues (43microg/m(3)). Indoor PM(2.5) levels were significantly associated with country, type of venue, smoking density and air exchange rate (p<0.05). In the seven Asian countries, PM(2.5) levels were high due to SHS in public places. The current levels are comparable to the levels in Western countries before the adoption of smoke-free policy. Since Asian country has high prevalence of SHS in public places, there is an urgent need for comprehensive smoke-free regulation in Asian countries.

Respiratory symptoms and illnesses among brick kiln workers: a cross sectional study from rural districts of Pakistan

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.

Pattern and predictors for respiratory illnesses and symptoms and lung function among textile workers in Karachi, Pakistan

Objectives To determine pattern and predictors for respiratory illnesses and symptoms and lung function among textile workers in Karachi, Pakistan. Methods This was a cross-sectional survey of 372 adult male textile workers from the spinning and weaving sections of 15 textile mills from Karachi. Data were collected from November to December 2009 through a structured, pretested questionnaire and spirometry. Results Prevalence of byssinosis was 10.5%, chronic cough 7.5%, chronic phlegm 12.9%, wheeze with shortness of breath 22.3%, shortness of breath (grade 2) 21%, chest tightness ever 33.3%; whereas, a low prevalence of asthma (4%) was identified in this population. Eight per cent had obstructive, 8% restrictive and 2% mixed pattern of lung function abnormality. After controlling for potential confounders, work in the spinning section predicts frequent wheeze (AOR=2.0; 95% CI 1.1 to 3.5), wheeze with shortness of breath (AOR=1.8; 95% CI 1.0 to 3.4), and obstructive pattern on spirometry (AOR=2.5; 95% CI 1.0 to 6.2). Prolonged duration of work predicts breathlessness grade 1 (AOR=1.8; 95% CI 1.0 to 3.1) and grade 2 (AOR=2.7; 95% CI 1.3 to 5.4), as well as decrements in Forced Expiratory Volume in the first second (FEV1) and FEV1/Forced Vital Capacity ratio. Lack of education predicts frequent wheeze (AOR=2.0; 95% CI 1.2 to 3.3), and Sindhi ethnicity predicts chest tightness apart from during cold (AOR=2.7; 95% CI 1.1 to 6.6). Conclusions 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.

Indoor air pollution (PM2.5) due to secondhand smoke in selected hospitality and entertainment venues of Karachi, Pakistan

Objective To determine particulate matter smaller than 2.5 μm (PM2.5) levels at various hospitality and entertainment venues of Karachi, Pakistan. Methods This was a descriptive cross-sectional study conducted at various locations in Karachi, during July 2009. Sampling was performed at 20 enclosed public places, including hospitality (restaurants and cafés) and entertainment (snooker/billiard clubs and gaming zones) venues. PM2.5 levels were measured using an aerosol monitor. Results All entertainment venues had higher indoor PM2.5 levels as compared to the immediate outdoors. The indoor PM2.5 levels ranged from 25 to 390 μg/m3 and the outdoor PM2.5 levels ranged from 18 to 96 μg/m3. The overall mean indoor PM2.5 level was 138.8 μg/m3 (±112.8). Among the four types of venues, the highest mean indoor PM2.5 level was reported from snooker/billiard clubs: 264.7 μg/m3 (±85.4) and the lowest from restaurants: 66.4 μg/m3 (±57.6) while the indoor/outdoor ratio ranged from 0.97 to 10.2, highest being at the snooker/billiard clubs. The smoking density ranged from 0.21 to 0.57, highest being at gaming zones. The indoor PM2.5 concentration and smoking density were not significantly correlated (Spearmans correlation coefficient=0.113; p=0.636). Conclusions This study demonstrates unacceptably high levels of PM2.5 exposure associated with secondhand smoke (SHS) at various entertainment venues of Karachi even after 8 years since the promulgation of smoke-free ordinance (2002) in Pakistan; however, better compliance may be evident at hospitality venues. The results of this study call for effective implementation and enforcement of smoke-free environment at public places in the country.

Correlation of respiratory symptoms and spirometric lung patterns in a rural community setting, Sindh, Pakistan: a cross sectional survey

BackgroundSymptom-based questionnaires can be a cost effective tool enabling identification and diagnosis of patients with respiratory illnesses in resource limited setting. This study aimed to determine the correlation of respiratory symptoms and spirometric lung patterns and validity of ATS respiratory questionnaire in a rural community setting.MethodsThis cross sectional survey was conducted between January – March 2009 on a sample of 200 adults selected from two villages of district Khairpur, Sindh, Pakistan. A modified version of the American thoracic society division of lung disease questionnaire was used to record the presence of respiratory symptoms. Predicted lung volumes i.e. forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and their ratio (FEV1/FVC) were recorded using portable spirometer.ResultsIn the study sample there were 91 (45.5%) males and 109 (54.5%) females with overall mean age of 34 years (±11.69). Predominant respiratory symptom was phlegm (19%) followed by cough (17.5%), wheeze (14%) and dyspnea (10.5%). Prevalence of physician diagnosed and self-reported asthma was 5.5% and 9.5% respectively. Frequency of obstructive pattern on spirometry was 28.72% and that of restrictive pattern was 19.68%. After adjustment for age, gender, socioeconomic status, spoken dialect, education, smoking status, height, weight and arsenic in drinking water, FVC was significantly reduced for phlegm (OR 3.01; 95% CI: 1.14 – 7.94), wheeze (OR 7.22; 95% CI: 2.52 – 20.67) and shortness of breath (OR 4.91; 95% CI: 1.57 – 15.36); and FEV1 was significantly reduced for cough (OR 2.69; 95% CI: 1.12 – 6.43), phlegm (OR 3.01; 95% CI: 1.26 – 7.16) and wheeze (OR 10.77; 95% CI: 3.45 – 33.6). Presence of respiratory symptoms was significantly associated with restrictive and/or obstructive patterns after controlling for confounders. Similar findings were observed through linear regression where respiratory symptoms were found to be significantly associated with decrements in lung volumes. Specificity and positive predictive values were found to be higher for all the symptoms compared to sensitivity and negative predictive values.ConclusionSymptoms based respiratory questionnaires are a valuable tool for screening of respiratory symptoms in resource poor, rural community setting.

Burden of asthma among children in a developing megacity: childhood asthma study, Pakistan

Abstract Objectives: Global burden of childhood asthma has increased in the past few decades, particularly in low-income countries. In Pakistan, there is a lack of community-based epidemiological studies estimating the burden of asthma among children. This study determined the prevalence and predictors of asthma among children 3–17 years of age in Karachi, Pakistan. Methods: A two-stage community-based representative cross-sectional survey was conducted in Karachi from March 2012 to April 2013 comprising 1046 children aged 3–17 years. Of 7500 clusters, 80 were randomly selected, and of these, 15 children per cluster were enrolled randomly. A translated and pre-tested version of International Study of Asthma and Allergies in Children questionnaire was administered. Results: The overall prevalence of asthma among study participants was 10.2% (95% CI: 8.4–12.0). Asthma was more likely to occur among boys (adj. OR: 2.5, 95% CI: 1.6–4.0), children in the younger age group (3–7 years) (adj. OR: 2.9, 95% CI: 1.7–4.8), those living in households with ill-ventilated kitchens (adj. OR: 1.8, 95% CI: 1.1–3.1), having family history of asthma (adj. OR: 2.3, 95% CI: 1.3–3.9) and those of the Sindhi ethnicity (adj. OR: 2.2, 95% CI: 1.1–4.4). Conclusion: This study is the first robust evidence regarding asthma among children in Pakistan, reporting a high burden in this group. Family history, male gender, Sindhi ethnicity and ill-ventilated kitchen were identified as important predictors of asthma. Targeted preventive measures and intervention studies are required to better understand and reduce the burden of asthma among children in Pakistan.

Pulmonary Tuberculosis Is Associated With Biomass Fuel Use Among Rural Women in Pakistan: An Age- and Residence-Matched Case-Control Study:

Facility-based, age- and residential area–matched case-control study was conducted in Sindh, Pakistan to determine association between biomass fuel use for cooking and pulmonary tuberculosis (TB). Cases were women with pulmonary TB, and controls were those suffering from other diseases. Current users of biomass fuel were at higher risk of pulmonary TB (adjusted matched odds ratio [mOR] = 3.0; 95% CI = 1.1-4.9) compared with nonusers. In comparison with former biomass users (women not using biomass for >10 years), recent biomass users (women who switched from biomass to nonbiomass ≤10 years ago), and current (lifetime) users were at a higher risk in a dose-response manner (adjusted mOR = 2.8, 95% CI = 0.9-8.2 and adjusted mOR = 3.9, 95% CI = 1.4-10.7, respectively). Population attributable fraction for TB related to biomass fuel use was 40.6% (95% CI = 35.5%-45.7%). This study strengthens the evidence that biomass fuel use for cooking is associated with pulmonary TB and risk increases with duration of exposure.

Dose-response of Cotton Dust Exposure with Lung Function among Textile Workers: MultiTex Study in Karachi, Pakistan

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, Berkeley-Particle, 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 (FEV1), forced vital capacity (FVC), and their ratio (FEV1/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 FEV1 82.6 (SD 14.0); FVC 90.3 (14.7), and FEV1/FVC 94.9 (10.5). The median cotton dust concentration was 0.61 (IQR 0.2 to 1.3) mg/m3. The frequency of respiratory symptoms was 15% for cough, 20% for phlegm, and 20% for wheezing. After adjustment for covariates, every mg/m3 increase in dust concentration was associated with 5.4% decline in FEV1. 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.