AIR-C3 Study - Applied Implementation Research for Clean Cooking in Cambodia
Over 3 billion people use biomass fuels (like wood, charcoal, and coal) for cooking. This leads to household air pollution (HAP), which causes about 2.3 million million premature deaths annually from cardiovascular and respiratory diseases, diabetes, kidney disease, cancer, and adverse birth outcomes. Attempts to make burning these fuels cleaner have not significantly reduced air pollution, replaced biomass stoves, or shown clear health benefits. Focus has now shifted to cleaner cooking solutions, such as liquefied petroleum gas (LPG) and electricity.
Recent evidence shows that using cleaner fuels can significantly lower exposure to hazardous air pollutants (HAP). In our Household Air Pollution Intervention Network (HAPIN) trial across multiple countries, providing households with free LPG stoves and fuel led to nearly full adoption and reduced exposures by over 60%. This change increased the percentage of households meeting the World Health Organization (WHO) guideline for fine particulate matter (PM2.5) from 17% to 66%. However, the exclusive use of LPG did not last after the trial ended, indicating the need for strategies to ensure ongoing use of clean cooking technologies. Additionally, LPG may not be ideal in some areas due to its cost, fuel access challenges, and pollution from burning it, which may limit health and climate benefits. This study will investigate electric induction cooking as a potentially cleaner and more effective technology on a large scale. Our project, Applied Implementation Research for Clean Cooking in Cambodia (AIR-C3), will create and assess strategies to encourage affordable purchase and consistent use of electric induction stoves among low-income households in peri-urban Cambodia through a hybrid type II trial. The specific aims are:
Aim 1. Develop, refine, and test implementation strategies for purchase and use of induction cookstoves. Through a three-phase, theory-informed learning and refinement approach, we will (a) identify determinants of stove purchase and use and biomass disuse, (b) develop public messaging and refine direct-sales and intervention strategies to promote purchase and use among participating households; and (c) establish targeted induction stove and electricity subsidies. We will apply established implementation science frameworks to map implementation determinants (facilitators and barriers) against intervention functions (e.g., incentives, modeling, education). Rapid prototyping and trials of improved practices will allow us to refine the resulting implementation strategies to be packaged and tested in Aim 2.
Aim 2. Evaluate novel induction stove promotion strategies on stove purchase and use with a hybrid type II cluster-randomized trial. We will randomly allocate 62 peri-urban villages to receive one of four integrated implementation strategies—direct sales with varied pro-poor subsidies or public sector distribution. Using the RE-AIM framework, we will assess the number, proportion, and characteristics of households Reached by the strategies; the impact of implementation strategies on purchase and use of induction (primary outcomes), disuse of biomass fuels, and exposures to PM2.5, and assess determinants of use (Effectiveness); the barriers and enablers of Adoption by implementers in Cambodia; delivery, fidelity, and dose of Implementation strategies; and Maintenance of effectiveness and implementation outcomes.
Aim 3. Estimate costs, benefits, and incremental cost-effectiveness of the stove promotion strategies. We will measure costs and direct and indirect benefits of the intervention strategies designed in Aim 1 and tested in Aim 2 to (a) model health benefits attributable to exposure reductions; (b) calculate reductions in airborne pollutants; (c) monetize changes in household time-activity, and (d) assess outcomes based on traditional cooking roles and responsibilities. We will also evaluate implementation costs per household targeted and per household switching to use of induction stoves using a societal perspective. We will model the costs of strategies and policies to scale up implementation.
We will be among the first to measure the impact of theory- and evidence-based promotion strategies to increase uptake and sustained use of induction stoves to reduce biomass fuel use. We will apply systematic approaches to implementation strategy development, establish plausible mechanisms of change for these strategies, and conduct a robust economic evaluation as part of a hybrid trial design. Our novel measurements on the effectiveness of induction cooking for reducing HAP exposures among underserved communities will establish the feasibility and potential health benefits of induction cooking, with an emphasis of reducing exposure to women (who serve as the primary cooks), health, and welfare. We will provide actionable strategies to achieve equitable, sustainable access to induction stoves that may translate to other cleaner cooking technologies across Southeast Asia and elsewhere and highlight the value of implementation science for addressing persistent global health challenges.
Timeline
2024-2029
Study Location
Principal Investigators
Emory University: Matthew Freeman
University of California, Berkeley: Ajay Pillarisetti
Funders
National Institute of Environmental Health Sciences (1R01ES035395-01A1)
Project Staff
Jedidiah Snyder, Allison Salinger
Co-Investigators
Emory University: Bethany Caruso, Sheela Sinharoy, Thomas Clasen, Howard Chang
iDE: Phearak Maksay, Jennifer Roglà
University of South Carolina: David Fuente
Colorado State University: Jennifer Peel
IMPLEMENTING Team
iDE Cambodia: Kevin Robbins, Kim Hian Seng, Fatima Shehata, Choun Samnang, Lyta Kater
students
Emory University: Devi Prasad (PhD Student), Lyvannak Sam (MPH Student)
University of California, Berkeley: Alexandra Johnson (PhD Student), Pratiyush Singh (MPP Student), Chelsea Lam (undergraduate)
Advisors
Jonny Crocker