Exposure Contrasts of Women Aged 40–79 Years during the Household Air Pollution Intervention Network Randomized Controlled Trial

Exposure to household air pollution has been linked to adverse health outcomes among women aged 40–79. Little is known about how shifting from biomass cooking to a cleaner fuel like liquefied petroleum gas (LPG) could impact exposures for this population. We report 24-h exposures to particulate matter (PM2.5), black carbon (BC), and carbon monoxide (CO) among women aged 40 to <80 years participating in the Household Air Pollution Intervention Network trial. 209 participants were randomized to the intervention and received an LPG stove and continuous fuel supply; controls used biomass (n = 209). Exposures were measured up to six times; we used mixed-effects models to estimate differences between intervention and control groups. Preintervention exposures between groups were comparable; median postintervention exposures were 62% (76.3 vs 29.3 μg/m3), 73% (10.4 vs 2.8 μg/m3), and 57% (1.4 vs 0.6 ppm) lower for PM2.5, BC, and CO among LPG users than for controls. Reductions were similar across countries; 70% of PM2.5 exposures after intervention were below the annual WHO interim target I (IT-1) value of 35 μg/m3. We provide evidence that implementing an LPG intervention can reduce air pollution exposure over an 18-month period to at or below the annual WHO IT-1 guideline.