Household Air Pollution Concentrations after Liquefied Petroleum Gas Interventions in Rural Peru: Findings from a One-Year Randomized Controlled Trial Followed by a One-Year Pragmatic Crossover Trial

BACKGROUND: Household air pollution (HAP) from biomass fuel combustion remains a leading environmental risk factor for morbidity worldwide. OBJECTIVE: Measure the effect of liquefied petroleum gas (LPG) interventions on HAP exposures in Puno, Peru. METHODS: We conducted a 1-y randomized controlled trial followed by a 1-y pragmatic crossover trial in 180 women age 25–64 y. During the first year, intervention participants received a free LPG stove, continuous fuel delivery, and regular behavioral messaging, whereas controls continued their biomass cooking practices. During the second year, control participants received a free LPG stove, regular behavioral messaging, and vouchers to obtain LPG tanks from a nearby distributor, whereas fuel distribution stopped for intervention participants. We collected 48-h kitchen area concentrations and personal exposures to fine particulate matter (PM) with aerodynamic diameter [Formula: see text] ([Formula: see text]), black carbon (BC), and carbon monoxide (CO) at baseline and 3-, 6-, 12-, 18-, and 24-months post randomization. RESULTS: Baseline [Formula: see text] [Formula: see text] (kitchen area concentrations [Formula: see text] vs. [Formula: see text]; personal exposure [Formula: see text] vs. [Formula: see text]), CO (kitchen [Formula: see text] vs. [Formula: see text]; personal [Formula: see text] vs. [Formula: see text]), and BC (kitchen [Formula: see text] vs. [Formula: see text]; personal [Formula: see text] vs. [Formula: see text]) were similar between control and intervention participants. Intervention participants had consistently lower [Formula: see text] concentrations at the 12-month visit for kitchen ([Formula: see text] , [Formula: see text] , and [Formula: see text]) and personal exposures ([Formula: see text] , [Formula: see text] , and [Formula: see text]) to [Formula: see text] , BC, and CO when compared to controls during the first year. In the second year, we observed comparable HAP reductions among controls after the voucher-based intervention for LPG fuel was implemented (24-month visit [Formula: see text] , BC, and CO kitchen mean concentrations of [Formula: see text] , [Formula: see text] , and [Formula: see text] and personal exposures of [Formula: see text] , [Formula: see text] , and [Formula: see text] , respectively), and average reductions were present among intervention participants even after free fuel distribution stopped (24-month visit [Formula: see text] , BC, and CO kitchen mean concentrations of [Formula: see text] , [Formula: see text] , and [Formula: see text] and personal exposures of [Formula: see text] , [Formula: see text] , and [Formula: see text] , respectively). DISCUSSION: Both home delivery and voucher-based provision of free LPG over a 1-y period, in combination with provision of a free LPG stove and longitudinal behavioral messaging, reduced HAP to levels below 24-h World Health Organization air quality guidelines. Moreover, the effects of the intervention on HAP persisted for a year after fuel delivery stopped. Such strategies could be applied in LPG programs to reduce HAP and potentially improve health. https://doi.org/10.1289/EHP10054