Kaali et al. discuss the paper by Checkley and colleagues which examines the effect of a year-long, multifaceted liquefied petroleum gas (LPG) cookstove intervention as compared with biomass (commonly animal dung) cookstove on cardiopulmonary health in adults, specifically resting BP, peak expiratory flow (PEF), and respiratory symptoms as measured by the St. George's Respiratory Questionnaire. The primary finding of this impressive study was that a year-long LPG intervention with robust measures to enable LPG stove use was not associated with improvement in BP, PEF, or respiratory symptoms in women randomized to the cleaner burning LPG stove as compared with control. Strikingly, exposure-response analyses found no association between average personal PM2.5 exposure and systolic or diastolic BP or postbronchodilator PEF (but did suggest that higher personal PM2.5 exposure was associated with lower prebronchodilator PEF).