Burden of Respiratory Diseases Attributable to Household Air Pollution in Nepal: National and Provincial Estimates

Background: Household air pollution (HAP) is widespread in Nepal particularly in rural poor households where use of unprocessed biomass fuels (wood, animal dung and crop residues) for cooking is abundant. Studies have shown that health effects associated with HAP are primarily respiratory and cardiovascular diseases which are amongst the top burden of diseases in Nepal. 
Objective: The study is conducted to estimate Attributable Fraction (AF) and corresponding Attributable Burden (AB) of diseases such as childhood pneumonia, acute respiratory infection/pneumonia and COPD/asthma which can be associated with HAP in Nepal, nationally and sub-nationally. 
Materials and Methods: Estimates on fuel use in Nepal disaggregated by rural and urban areas and provinces are obtained from Nepal Multiple Indicator Cluster Survey (NMICS), 2019 published by Central Bureau of Statistics (CBS). The corresponding total disease burdens of Nepal related to respiratory diseases are obtained from the Department of Health Services (DoHS) for 2019/20. Estimates of model coefficients of the targeted respiratory diseases that can be attributed to HAP are obtained from several studies conducted previously in Nepal. Methodology adopted by World Health Organization (WHO) for estimation of AF and AB is applied in the present analysis. 
Results: The estimated AF and AB of childhood pneumonia, ARI/pneumonia and COPD/asthma are obtained as 34.6% (95% CI = 7.4%-56.4%) and 7.3 (96% CI = 1.5-11.8) per 1000 under five children, 42.5% and 63.6 per 1000 population and 54.8% and 10.3 per 1000 population, respectively. AFs are found substantially higher (1.3-1.5 times) in rural Nepal compared to urban Nepal. Provincially, Karnali is found worst affected with highest attributions (45.3% - 65.6%) for the accounted burden of diseases and Bagmati found least affected with lowest attributions (18.7% - 34.6%) for the year 2019/20. 
Conclusion: HAP is found to be a potential risk factor with high attributions for the occurrence of respiratory ailments in Nepal.