Exposure to indoor biomass fuel and tobacco smoke and risk of adverse reproductive outcomes, mortality, respiratory morbidity and growth among newborn infants in south India

Background Exposure to indoor air pollution due to open burning of biomass fuel is common in low- and middle-income countries. Previous studies linked this exposure to an, increased risk of respiratory illness, low birth weight (LBW) and other disorders. We assessed the association between exposure to biomass fuel sources and second-hand tobacco smoke (SHTS) in the home and adverse health outcomes in early infancy in a population in rural south India. Methods A population-based cohort of newborns was followed from birth through 6 months. Household characteristics were assessed during an enrolment interview including the primary type of cooking fuel and smoking behaviour of household residents. Follow-up visits for morbidity were carried out every 2 weeks after delivery. infants were discharged at 6 months when anthropometric measurements were collected. Results 11728 live-born infants were enrolled and followed, of whom 92.3% resided in households that used wood and/or dung as a primary source of fuel. Exposure to biomass fuel was associated with an adjusted 49% increased risk of LBW, a 34% increased incidence of respiratory illness and a 21% increased risk of 6-month infant mortality. Exposed infants also had 45 and 30% increased risks of underweight and stunting at 6 months. SHTS exposure was also associated with these adverse health outcomes except for attained growth. Conclusions Open burning of biomass fuel in the home is associated with significant health risks to the newborn child and young infant. Commnunity-based trials are needed to clarify causal connections and identify effective approaches to reduce this burden of illnesses.