Childhood illness in households using biomass fuels in India: secondary data analysis of nationally representative national family health surveys

Background: Half of the world's population uses solid fuels for energy and cooking, resulting in 1.5 million deaths annually, approximately one-third of which occur in India. Most deaths are linked to childhood pneumonia or acute lower respiratory tract infection (ALRI), conditions that are difficult to diagnose. The overall effect of biomass combustion on childhood illness is unclear. Objectives: To evaluate whether type of household fuel is associated with symptoms of ALRI (cough and difficulty breathing), diarrhea or fever in children aged 0-36 months. Methods: We analyzed nationally representative samples of households with children aged 0-36 months from three national family health surveys conducted between 1992 and 2006 in India. Households were categorized as using low (liquid petroleum gas/electricity), medium (coal/kerosene) or high polluting fuel (predominantly wood/agricultural waste). Odds ratios adjusted for confounders for exposure to high and medium polluting fuel were compared with low polluting fuel (LPF). Results: Use of high polluting fuel (HPF) in India changed minimally (82 to 78 %), although LPF use increased from 8% to 18%. HPF was consistently associated with ALRI [ adjusted odds ratio (95% confidence interval) 1.48 (1.08-2.03) in 1992-3; 1.54 (1.33-1.77) in 1998-9; and 1.53 (1.21-1.93) in 2005-6). Fever was associated with HPF in the first two surveys but not in the third survey. Diarrhea was not consistently associated with HPF. Conclusions: There is an urgent need to increase the use of LPF or equivalent clean household fuel to reduce the burden of childhood illness associated with IAP in India.