Air quality and respiratory health: prevalence, knowledge, and practices in Dhaka’s informal settlements - a cross-sectional study

Abstract

Background: Several studies suggest that air pollution causes morbidity and mortality, this problem is particularly severe in developing countries. However, little is known about the prevalence of respiratory symptoms among adults in informal settlements with varying air pollution and their practice and knowledge status regarding air pollution and its impact on health. The objective of this study is to explore the prevalence of respiratory symptoms in two informal settlements in Dhaka and the knowledge and practice status of the adult residents. Methods: The study design was cross-sectional and was conducted in Shyampur and Dakshinkhan areas. These study sites were selected based on air quality data collected from a study conducted in BRAC JPGSPH in 2023. Shyampur was selected for having comparatively high air pollution, whereas Dakshinkhan was chosen for having comparatively low air pollution. A total of 316 adult residents were interviewed. This study used multiple sequential logistic regression models to examine the relationship between respiratory symptoms, sociodemographic, and environmental factors, and knowledge and practice status. Results: The proportion of people having respiratory symptoms in Shyampur and Dashinkhan areas were 60.26% and 55.41% respectively. Knowledge status varied in the two areas, while the practice status was almost equal in Shyampur and Dakshinkhan. Results of the sequential multiple logistic regression revealed that the participants in Dakshinkhan had lower odds of having respiratory symptoms (OR= 0.61; 95% CI: 0.36-1.01) compared to Shyampur area. The odds of suffering from respiratory symptoms were significantly associated with individuals who are aged 50 years and above ( OR= 2.31; 95% CI: 1.07-4.98); those who were aged 30-39 years old (OR= 2.05; 95% CI: 1.11-3.82); exposure to indoor smoking (OR= 1.53; 95% CI:0.93-2.50), higher income level ( OR=1.91; 95% CI:1.04-3.49), knowledge status (Good level) ( OR= 2.07; 95% CI: 1.06-4.05), knowledge status (moderate level) ( OR = 2.07, 95% CI: 1.06-4.05). In stratified logistic regression analysis age, income, and exposure to smoking indoors showed a significant association, while in Dakshinkhan resident’s knowledge status was significantly associated with respiratory symptoms. Conclusion: The impact on respiratory symptoms is higher in areas with comparatively high pollution than in areas with comparatively low pollution. Along with socio-demographic and environmental factors, housing conditions, and participant’s knowledge status emerged as significant variables in predicting respiratory symptoms in informal settlements.