Household Air Pollution and Health: A Multi-country LPG Intervention Trial

Globally, nearly 3 billion people rely on solid fuels for cooking and heating, the vast
majority in low- and middle-income countries (LMICs). The resulting household air pollution
(HAP) is the third leading risk factor in the 2010 global burden of disease, accounting for
an estimated 4.3 million deaths annually, largely among women and young children. Previous
interventions have provided cleaner biomass-based cookstoves, but have failed to reduce
exposure to levels that produce meaningful health improvements. There have been no
large-scale field trials with liquefied petroleum gas (LPG) cookstoves, likely the cleanest
scalable intervention.

The aim of this study is to conduct a randomized controlled trial of LPG stove and fuel
distribution in 3,200 households in four LMICs (India, Guatemala, Peru, and Rwanda) to
deliver rigorous evidence regarding potential health benefits across the lifespan. Each
intervention site will recruit 800 pregnant women (aged 18-34 years, <20 weeks gestation),
and will randomly assign half their households to receive LPG stoves and a 30-month supply
of LPG. Controls will receive the same cookstoves and LPG supply at the end of the study.
The mother will be followed along with her child until the child is 2 years old. In
households with a second, non-pregnant older adult woman (aged 35-64 years) the researchers
will also enroll and follow her during the 30-month follow-up period in order to assess
cardiopulmonary, metabolic, and cancer outcomes. To optimize intervention use, the
researchers will implement behavior change strategies. This study will assess cookstove use,
conduct repeated personal exposure assessments to HAP (PM2.5, black carbon, carbon
monoxide), and collect dried blood spots and urinary samples for biomarker analysis and
biospecimen storage on all participants at multiple time points. The primary outcomes are
low birth weight, pneumonia incidence, and linear growth in the child, and blood pressure in
the older adult woman. Secondary outcomes include preterm birth and gross motor development
in the child, maternal blood pressure during pregnancy, and endothelial function,
respiratory impairment, carcinogenic metabolites, and quality of life in the older adult
woman.

This study will address the following specific aims: (1) using an intent-to-treat analysis,
determine the effect of a randomized LPG stove and fuel intervention on health in four
diverse LMIC populations using a common protocol; (2) determine the exposure-response
relationships for HAP and health; and (3) determine relationships between LPG intervention
and both targeted and exploratory biomarkers of exposure/health effects.

This study will provide compelling evidence, including costs and implementation strategies,
to inform national and global policies on scaling up LPG stoves among vulnerable
populations. Ultimately, this will facilitate deeper policy-level discussions as well as
identify requirements for initiating and sustaining HAP interventions globally.

Inclusion Criteria for Pregnant Women:

- Age of 18 to 34 years old

- <20 weeks gestation confirmed by ultrasound

- Singleton pregnancy

- No fetal anomalies identified during first ultrasound

- Use biomass stove

- Not currently a smoker

- No plans to move out of her current household in next 30 months

- Agrees to participate with informed consent

Exclusion Criteria for Pregnant Women:

- Lives in household that has LPG stove

Inclusion Criteria for Older Adult Woman in the Same Household:

- Aged 35-64 years

- Not currently a smoker

- No plans to move out of her current household in the next 30 months

Exclusion Criteria for Older Adult Woman in the Same Household:

- Use of anti-hypertensives