Attributable risk and potential impact of interventions to reduce household air pollution associated with under-five mortality in South Asia

Background:Solid fuel use is the major source of household air pollution(HAP)and accounts for a substantial burden of morbidity and mortality in low and middle income countries.To evaluate and compare childhood mortality attributable to HAP in four South Asian countries.Methods:A series of Demographic and Health Survey(DHS)datasets for Bangladesh,India,Nepal and Pakistan were used for analysis.Estimates of relative risk and exposure prevalence relating to use of cooking fuel and under-five mortality were used to calculate population attributable fractions(PAFs)for each country.Potential impact fractions(PIFs)were also calculated assessing theoretical scenarios based on published interventions aiming to reduce exposure prevalence.Results:There are an increased risk of under-five mortality in those exposed to cooking fuel compared to those not exposed in the four South Asian countries(OR=1.30,95%CI=1.07-1.57,P=0.007).Combined PAF estimates for South Asia found that 66%(95%CI:43.1-81.5%)of the 13,290 estimated cases of under-five mortality was attributable to HAP.Joint PIF estimates(assuming achievable reductions in HAP reported in intervention studies conducted in South Asia)indicates 47%of neonatal and 43%of under-five mortality cases associated with HAP could be avoidable in the four South Asian countries studied.Conclusions:Elimination of exposure to use of cooking fuel in the household targeting valuable intervention strategies(such as cooking in separate kitchen,improved cook stoves)could reduce substantially under-five mortality in South Asian countries.