Exposure Contrasts\nof Women Aged 40–79 Years\nduring the Household Air Pollution Intervention Network Randomized\nControlled Trial

Exposure to household air pollution has been linked to\nadverse\nhealth outcomes among women aged 40–79. Little is known about\nhow shifting from biomass cooking to a cleaner fuel like liquefied\npetroleum gas (LPG) could impact exposures for this population. We\nreport 24-h exposures to particulate matter (PM<sub>2.5</sub>), black\ncarbon (BC), and carbon monoxide (CO) among women aged 40 to <80\nyears participating in the Household Air Pollution Intervention Network\ntrial. 209 participants were randomized to the intervention and received\nan LPG stove and continuous fuel supply; controls used biomass (<i>n</i> = 209). Exposures were measured up to six times; we used\nmixed-effects models to estimate differences between intervention\nand control groups. Preintervention exposures between groups were\ncomparable; median postintervention exposures were 62% (76.3 vs 29.3\nμg/m<sup>3</sup>), 73% (10.4 vs 2.8 μg/m<sup>3</sup>),\nand 57% (1.4 vs 0.6 ppm) lower for PM<sub>2.5</sub>, BC, and CO among\nLPG users than for controls. Reductions were similar across countries;\n70% of PM<sub>2.5</sub> exposures after intervention were below the\nannual WHO interim target I (IT-1) value of 35 μg/m<sup>3</sup>. We provide evidence that implementing an LPG intervention can reduce\nair pollution exposure over an 18-month period to at or below the\nannual WHO IT-1 guideline.