Broadly, we focus on the impacts of energy use - typically at the household level -- on air pollution, climate, and health. While progress on providing clean household energy arguably follows development trajectories, there is need to accelerate the transition to clean cooking through innovative policy and dissemination approaches. Our research group builds the evidence base for these transitions -- based on health, environmental, and economic benefits -- using the multidisciplinary field of Environmental Health Sciences, which sits at the interface of laboratory science, aerosol chemistry, environmental engineering, and implementation science, as the foundation of our work. Our work falls into some broad thematic areas, discussed below.
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.
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.
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.
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 recent Air Pollution Special Issue (Science 385) does a laudable job highlighting the global scientific community’s ability to quantify air pollution and its impacts and translate findings into policy-relevant recommendations. We contend, however, that it gives insufficient consideration to one of the oldest and leading sources of health-damaging pollution: cooking and heating with solid fuels (wood, dung, charcoal, coal, crop residues). ~3 million deaths yearly are attributable to the resulting household air pollution, which also contributes to climate change (1).
How bad is the air pollution associated with solid fuel use? Of ~12,000 PM2.5 measurements made in households or on individuals using solid fuels, 1% were at or below the annual WHO Interim Target 1 guideline value of 35 µg/m3 (2). None attained the guideline value of 5 ug/m3. In other words, we expect that none of the 3 billion people without access to clean household energy experience air quality that satisfies the WHO guideline.
Advances in lower-cost sensing, as discussed in Apte et al (Science 385, 380-385), have enabled better resolved air pollution estimates and novel justice-focused analyses. They have not been widely applied in rural communities, especially indoors among households using solid fuels. Similarly, the goal of universal clean air, as discussed by Huang et al (Science 385, 386-390), cannot be met without commitment to reducing inequities in the impacts of household air pollution in low- and middle-income countries (LMICs).
Cleaner biomass alternatives—gas and electricity—have been available for decades and are commonplace among wealthier households in LMICs and widely in developed nations. While access to these cleaner technologies is increasing, their exclusive use lags in LMICs due to cost, availability, and reliability of supply (3). Global momentum to ban fossil fuel use has affected support for scaling clean household energy in LMICs, even while fossil fuels continue to power the economies of developed nations and the homes of their citizens. Without drastic policy measures to enable near-term clean energy transitions, which likely includes LPG, we run the risk of exacerbating exposure and health inequities among vulnerable communities (4).
Policies reducing HAP have many benefits: decreased exposure of household members by eliminating solid fuel use (5); reduced community exposures by removing many point sources; and improved air quality for entire airsheds (6). Efforts to improve measurement of HAP exposures and of rural air pollution similarly serve multiple purposes: they provide an important baseline of pollution people actually experience; they enable calibration of model- or satellite- based pollution estimates; and they enable accountability studies of policies that may improve ambient air (e.g. programs transitioning from biomass to gas or electricity).
No global health discourse on air pollution can be complete without adequate emphasis on household air pollution exposures that impact the poorest three billion with limited bargaining power for energy or health equity. We implore continued emphasis on this public health risk in every forum concerned with air pollution and health.
References
1. Health Effects Institute. “State of Global Air 2024.” Special Report.(Boston, MA:Health Effects Institute., 2024.
2. M. Shupler, K. Balakrishnan, S. Ghosh, G. Thangavel, S. Stroud-Drinkwater, H. Adair-Rohani, J. Lewis, S. Mehta, M. Brauer, Global household air pollution database: Kitchen concentrations and personal exposures of particulate matter and carbon monoxide. Data in Brief 21, 1292–1295 (2018).
3. E. Puzzolo, D. Pope, D. Stanistreet, E. A. Rehfuess, N. G. Bruce, Clean fuels for resource-poor settings: A systematic review of barriers and enablers to adoption and sustained use. Environmental Research 146, 218–234 (2016).
4. C. F. Gould, R. Bailis, K. Balakrishnan, M. Burke, S. Espinoza, S. Mehta, S. B. Schlesinger, J. R. Suarez-Lopez, A. Pillarisetti, In praise of cooking gas subsidies: transitional fuels to advance health and equity *. Environ. Res. Lett. 19, 081002 (2024).
5. M. Johnson, A. Pillarisetti, R. Piedrahita, K. Balakrishnan, J. L. Peel, K. Steenland, L. J. Underhill, G. Rosa, M. A. Kirby, A. Díaz-Artiga, J. McCracken, M. L. Clark, L. Waller, H. H. Chang, J. Wang, E. Dusabimana, F. Ndagijimana, S. Sambandam, K. Mukhopadhyay, K. A. Kearns, D. Campbell, J. Kremer, J. P. Rosenthal, W. Checkley, T. Clasen, L. Naeher, and the Household Air Pollution Intervention Network (HAPIN) Trial Investigators, Exposure Contrasts of Pregnant Women during the Household Air Pollution Intervention Network Randomized Controlled Trial. Environ Health Perspect 130, 097005 (2022).
6. S. Chowdhury, S. Dey, S. Guttikunda, A. Pillarisetti, K. R. Smith, L. Di Girolamo, Indian annual ambient air quality standard is achievable by completely mitigating emissions from household sources. Proc Natl Acad Sci USA 116, 10711 (2019).
by Ajay Pillarisetti1*, Sumi Mehta2, Kalpana Balakrishnan3
1 School of Public Health, University of California, Berkeley; Berkeley, USA
2 Vital Strategies; New York, USA
3 Department of Environmental Health Engineering, Faculty of Public Health, Sri Ramachandra, Institute of Higher Education and Research; Chennai, India
rejected as a letter to the editor at Science
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 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.
Ye, W., Campbell, D., Johnson, M., Balakrishnan, K., Peel, J. L., Steenland, K., Underhill, L. J., Rosa, G., Kirby, M. A., Díaz-Artiga, A., McCracken, J., Thompson, L. M., Clark, M. L., Waller, L. A., Chang, H. H., Wang, J., Dusabimana, E., Ndagijimana, F., Sambandam, S., … Pillarisetti, A. (2024). Exposure Contrasts of Women Aged 40–79 Years during the Household Air Pollution Intervention Network Randomized Controlled Trial. In Environmental Science & Technology (Vol. 59, Issue 1, pp. 69–81). American Chemical Society (ACS). https://doi.org/10.1021/acs.est.4c06337
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 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.
Karakwende, P., Checkley, W., Chen, Y., Clark, M. L., Clasen, T., Dusabimana, E., Jabbarzadeh, S., Johnson, M., Kalisa, E., Kirby, M., Naher, L., Ndagijimana, F., Ndikubwimana, A., Ntakirutimana, T., Ntivuguruzwa, J. de D., Peel, J. L., Piedrahita, R., Pillarisetti, A., … Rosa, G. (2025). Predictors of Personal Exposure to Fine Particulate Matter, Black Carbon, and Carbon Monoxide among Pregnant Women in Rwanda: Baseline Data from the HAPIN Trial. In Journal of Health and Pollution (Vol. 13, Issue 1). Environmental Health Perspectives. https://doi.org/10.1289/jhp1049
Raheel, H., Sinharoy, S., Diaz-Artiga, A., Garg, S. S., Pillarisetti, A., Balakrishnan, K., Chiang, M., Lovvorn, A., Kirby, M., Ramakrishnan, U., Jabbarzadeh, S., Mukeshimana, A., Johnson, M., McCracken, J. P., Naeher, L. P., Rosa, G., Wang, J., Rosenthal, J., Checkley, W., … Thompson, L. M. (2025). Effects of a liquefied petroleum gas stove and fuel intervention on head circumference and length at birth: A multi-country household air pollution intervention network (HAPIN) trial. In Environment International (Vol. 195, p. 109211). Elsevier BV. https://doi.org/10.1016/j.envint.2024.109211
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.
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.