We engage in policy-oriented experiments to help justify continued investment in clean household energy. These range from cost-effectiveness analyses to behavior change campaigns to pragmatic, scalable policies targeting the most vulnerable populations.

Household air pollution contributes substantially to ambient air pollution. Estimates of this contribution range between 20 and 45% globally, with large spatial heterogeneity. Reducing household air pollution from solid fuel use thus has benefits across scales — it benefits people in homes who rely on these fuels, but also provides benefits to communities and airsheds by reducing ambient air pollution levels.

Interventions to decrease household air pollution exposures have a long history, ranging from so-called ‘improved’ biomass stoves that burn available fuels cleanly to clean fuels, like liquefied petroleum gas and ethanol, to electricity. Our group works on evaluating interventions from cost, environmental, climate, and health perspectives.

Our group makes measurements to estimate exposure and, in doing so, inform policies, evaluate interventions, and help provide evidence of potential health risk. Where instrumentation is lacking, we develop our own or adapt technologies used in other sectors and disciplines.

The Household Air Pollution Intervention Network (HAPIN) Trial is an international multi-center study aimed at assessing the impact of a liquefied petroleum gas (LPG) cooking stove and fuel intervention on health. HAPIN Trial centers are located in four countries: Guatemala, India, Peru and Rwanda.

The HAPIN Trial was launched in 2017 with formative research. Main trial enrollment started in 2018 and follow-up of participants ended in September 2021. More than 7,200 study participants were enrolled and will help the HAPIN Trial find answers to questions about LPG cookstoves and health. Currently the investigators are analyzing data for the primary outcomes: low birth weight, severe pneumonia incidence, and stunting in the child, and blood pressure in the older adult woman. Secondary outcomes include preterm birth and child development in the child, maternal blood pressure during pregnancy, and endothelial function, respiratory impairment, atherosclerosis, carcinogenic metabolites, and quality of life in the older adult woman. The team has been publishing manuscripts throughout project implementation.

The trial is funded by the National Institutes of Health (NIH) and the Bill & Melinda Gates Foundation. Participating NIH components are the National Heart, Lung, and Blood Institute (NHLBI), the National Cancer Institute, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute of Environmental Health Sciences, the NIH Common Fund of the NIH Office of the Director, and the Fogarty International Center. NHLBI leads administration of the trial on behalf of the consortium. The Global LPG Partnership provides expert advice. We are thankful for the guidance of our advisory committee: Patrick Brysse, Donna Spiegelman, and Joel Kaufman.

With Manish Desai, Krishnendu Mukhopadhyay, Naveen Puttaswamy, Sankar Sambandam, Gurusamy Thangavel, and Kalpana Balakrishnan.

The world’s most ambitious scale up of clean fuels has taken place across India in the past five years. The Pradhan Mantri Ujjwala Yojana (PMUY) program, building upon previous efforts, provided access to LPG for an additional 80 million homes. However, continued fuel stacking and inconsistent coverage of the intervention has left overall household air pollution exposure reductions in households and associated ambient air pollution reductions lower than what is needed to meet Indian national standards or WHO guidelines. Several recent modelling exercises suggest that household biomass burning results in significant contributions to ambient air pollution at national and regional levels. However, there is almost no actual data to support quantitative targets for program design and maintenance at the village and district level that could guide village coverage goals for household use of LPG to displace solid fuel burning. Because of the PMUY scale up history, patchy uptake at community levels, and relatively low level of industrial sources of pollution, Southern India provides an ideal setting to study the Reach and Effectiveness of this massive LPG program and to contribute evidence-based guidance to support critical implementation targets for policy around village- level coverage and LPG utilization.

With Pengbo Liu, PhD, MPH (Co-PI), Christine Moe, Danny Wilson, Ashley Styczynski, Nichole Starr, and N95Decon.

The global supply of personal protective equipment (PPE) – including surgical masks, N95 filtering facepiece respirators, gloves, and gowns – has been limited during the current pandemic. PPE serves as a first line of defense for healthcare workers and can play an important role in helping slow transmission of airborne pathogens like SARS-CoV-2. Our work focuses on two PPE-related aspects of the current pandemic. First, we will survey healthcare workers and facilities globally on their supply of PPE and usage practices. Second, we will evaluate methods of decontaminating cloth, surgical, and N95 masks that may be relevant for low-resource settings. Taken together, our findings can help optimize resource allocation and extend the use of existing supplies of PPE using decontamination methods suitable for low-resource settings.

With colleagues at Berkeley Air Monitoring Group, the World Bank, and LIRE (Vientiane), we are developing standard methods for estimating the health benefits (in the form of ADALYs – avoided disability-adjusted life years) that can be attributed to a stove project to introduce advanced combustion stoves in villages within the Savannakhet region of Laos. This project, led by L. Drew Hill, PhD, involved air pollution field work before and after the introduction of the stoves, modeling changes in personal exposure to PM2.5, and using the Household Air Pollution Intervention Tool (HAPIT) to calculate the estimated change in adult and child disease rates that would result.

This research quantifies the contribution of households to ambient air pollution in North India by (1) updating and improving existing emissions inventories through activity-based modeling at high temporal and spatial resolution, (2) providing field-based emissions of SVOCs and other ozone precursors to, for the first time, model the contribution of household air pollution to regional secondary particle formation; and (3) monitoring rural ambient and near-home concentrations of and personal exposures to PM2.5. Modeling efforts will enable manipulation of various sources and emission rates, across a variety of relevant policy scenarios, enabling estimation of how certain initiatives may impact air pollution at varying scales.

This project leverages a multi-year collaboration between University of California Berkeley and INCLEN, the International Clinical Epidemiology Network (New Delhi, India). INCLEN runs a large demographic and environmental surveillance site ~75 kilometers south of Delhi; their activities span over 50 villages covering approximately 200,000 individuals. While relatively close to Delhi, most households in the area rely on brushwood and dung as primary household fuels. The entire region is prone to low, ground-level inversions in the winter, resulting in especially high PM concentrations between November and February.

Study findings have been disseminated to local stakeholders, policy makers, members of relevant ministries, environmental health practitioners, and other researchers through journal articles.

In Maharashtra, India, we collaborated with Sri Ramachandra Institute of Higher Education and Research (SRIHER) and KEM Hospital Research Centre to provide clean fuels to pregnant women, recruited in the late first or early second trimester, in Pune district, Maharashtra, India. Our study sought to evaluate whether fuel use could be incentivized using a conditional cash transfer and, additionally, what the benefit and cost of providing free fuel during pregnancy would be in terms of pollution exposure reduction and exclusive use of clean fuels. Our study had multiple arms: one in which household received a clean LPG stove and two cylinders of fuel; one in which household were paid for their LPG use, using a novel conditional cash transfer sensor; and one in which households received free fuel for the duration of pregnancy (up to one free refill per month). Finally, we sought to assess the feasibility of targeting newly wed couples prior to conception; we did so because reducing exposures in the first trimesters is thought to be critical. Findings from the study, which was funded by the Clean Cooking Implementation Science Network, were extensively published.

With Lisa Thompson (Emory), Johannes Urpelainen (Johns Hopkins), Carlos Gould (Columbia), and Morsel Research and Development (Uttar Pradesh, India)

India has undergone a dramatic household energy transformation in recent years, driven by government initiatives to increase clean fuel access. These improvements have not led to complete transitions to clean cooking, with most households continuing regular biomass use, a trend that may be exacerbated by the COVID‐19 pandemic. We leverage and extend a recently completed energy survey of 1440 households in rural Jharkhand by deploying a follow‐up, telephone‐based questionnaire multiple times over the next year, enabling analysis of how COVID‐19 and stay‐at‐home orders alter energy use behaviors. Findings from this longitudinal study will help (1) understand drivers of stacking or exclusive LPG or biomass use; (2) provide insights into how resilient household energy use patterns are to sudden economic and social shocks; and (3) establish guidance that may inform planning for the next pandemic or other unexpected shock.

NBSP – a partnership between the International Clinical Epidemiology Network (INCLEN), Columbia University, UC Berkeley, and Sri Ramachandra Institute for Higher Education and Research (SRIHER) – evaluated the feasibility of distributing clean cookstoves through the rural antenatal care system, which targets arguably the most vulnerable population — poor, pregnant, rural women. The study distributed 200 blower stoves to pregnant women at INCLEN’s SOMAARTH field site and tracked usage of the stoves continuously for > 15 months using our Stove Use Monitoring System (SUMS) and measured pollutant concentrations and exposures before and after introduction of the stove. Funding for this project came from the United States Centers for Disease Control and Prevention, the World Lung Foundation, and the World Bank.