Patterns and predictors of personal exposure to indoor air pollution from biomass combustion among women and children in rural China

Indoor air pollution (IAP) from domestic biomass combustion is an important health risk factor, yet direct measurements of personal IAP exposure are scarce. We measured 24-h integrated gravimetric exposure to particles < 2.5 mu m in aerodynamic diameter (particulate matter, PM2.5) in 280 adult women and 240 children in rural Yunnan, China. We also measured indoor PM2.5 concentrations in a random sample of 44 kitchens. The geometric mean winter PM2.5 exposure among adult women was twice that of summer exposure [117 mu g/m(3) (95% CI: 107, 128) vs. 55 mu g/m(3) (95% CI: 49, 62)]. Children's geometric mean exposure in summer was 53 mu g/m(3) (95% CI: 46, 61). Indoor PM2.5 concentrations were moderately correlated with women's personal exposure (r = 0.58), but not for children. Ventilation during cooking, cookstove maintenance, and kitchen structure were significant predictors of personal PM2.5 exposure among women primarily cooking with biomass. These findings can be used to develop exposure assessment models for future epidemiologic research and inform interventions and policies aimed at reducing IAP exposure.