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BACKGROUND: Globally, nearly 3 billion people rely on solid fuels for cooking and heating, the vast majority residing in low- and middle-income countries (LMICs). The resulting household air pollution (HAP) is a leading environmental risk factor, accounting for an estimated 1.6 million premature deaths annually. Previous interventions of cleaner stoves have often failed to reduce exposure to levels that produce meaningful health improvements. There have been no multicountry field trials with liquefied petroleum gas (LPG) stoves, likely the cleanest scalable intervention. OBJECTIVE: This paper describes the design and methods of an ongoing randomized controlled trial (RCT) of LPG stove and fuel distribution in 3,200 households in 4 LMICs (India, Guatemala, Peru, and Rwanda). METHODS: We are enrolling 800 pregnant women at each of the 4 international research centers from households using biomass fuels. We are randomly assigning households to receive LPG stoves, an 18-month supply of free LPG, and behavioral reinforcements to the control arm. The mother is being followed along with her child until the child is 1 year old. Older adult women (40 to <80 years of age) living in the same households are also enrolled and followed during the same period. Primary health outcomes are low birth weight, severe pneumonia incidence, stunting in the child, and high blood pressure (BP) in the older adult woman. Secondary health outcomes are also being assessed. We are assessing stove and fuel use, conducting repeated personal and kitchen exposure assessments of fine particulate matter with aerodynamic diameter =2.5 ηm (PM2.5), carbon monoxide (CO), and black carbon (BC), and collecting dried blood spots (DBS) and urinary samples for biomarker analysis. Enrollment and data collection began in May 2018 and will continue through August 2021. The trial is registered with ClinicalTrials.gov (NCT02944682). CONCLUSIONS: This study will provide evidence to inform national and global policies on scaling up LPG stove use among vulnerable populations. [ABSTRACT FROM AUTHOR]

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 ≤ 2.5 µm (PM 2.5), black carbon (BC), and carbon monoxide (CO) at baseline and 3-, 6-, 12-, 18-, and 24-months post randomization. RESULTS. Baseline mean ± standard deviation (SD) PM2.5 (kitchen area concentrations 1,220 ± 1,010 vs. 1,190 ± 880 µg/m³; personal exposure 126 ± 214 vs. 104 ± 100 µg/m³), CO (kitchen 53 ± 49 vs. 50 ± 41 ppm; personal 7 ± 8 vs. 7 ± 8 ppm), and BC (kitchen 180 ± 120 vs. 210 ± 150 µg/m³; personal 19 ± 16 vs. 21 ± 22 µg/m³) were similar between control and intervention participants. Intervention participants had consistently lower mean (± SD) concentrations at the 12-month visit for kitchen (41 ± 59 µg/m³, 3±6 µg/m³, and 8 ± 13 ppm) and personal exposures (26 ± 34 µg/m³, 2±3 µg/m³, and 3 ± 4 ppm) to PM2.5, 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 PM2.5, BC, and CO kitchen mean concentrations of 34 ± 74 µg/m³,3±5 µg/m³, and 6 ± 6 ppm and personal exposures of 17 ± 15 µg/m³,2±2 µg/m³, and 3 ± 4 ppm, respectively), and average reductions were present among intervention participants even after free fuel distribution stopped (24-month visit PM2.5, BC, and CO kitchen mean concentrations of 561 ± 1,251 µg/m³, 82 ± 124 µg/m³, and 23 ± 28 ppm and personal exposures of 35 ± 38 µg/m³,6±6 µg/m³, and 4 ± 5 ppm, 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. [ABSTRACT FROM AUTHOR]