Extreme heat poses acute and chronic risks to workers across South Asia, yet personal exposure data from occupational settings remain scarce. Informal workers, who dominate textile and sanitation sectors, are disproportionately vulnerable: despite labor protections, they operate outside labor laws, lacking written contracts, social security, and healthcare benefits, while facing severe occupational, social, and economic hazards. Tamil Nadu is a major hub of India’s textile sector value chain. The state has recently surpassed Gujarat and Karnataka to emerge as the country’s leading textile exporter. While Tirupur and Erode have long dominated in textile manufacturing, Dindigul and Virudhunagar are emerging as significant centers, driven by Micro, Small and Medium Enterprises (MSME) concentration and Virudhunagar’s inclusion in the PM MITRA park programme. These districts are also experiencing escalating heat stress driven by climate change. Textile workers face sustained physical exertion in poorly ventilated factory floors, with heat risks compounded by hot commutes and heat-burdened homes. Sanitation workers face a similarly compounding vulnerability. By 2015, Tamil Nadu had outsourced sanitation work to contractual workers, the majority of whom were women. Drawn from particularly marginalized communities, these workers are exposed to severe occupational hazards such as harmful gases, sharp object injuries, and musculoskeletal disorders, while lacking adequate Personal Protective Equipment (PPE) and labor protections. Rising temperatures render this dangerous work increasingly life-threatening. Across both sectors, standard heat-health surveillance relies on ambient outdoor temperature, which fails to capture the layered exposures workers experience across workplace, transit, and domestic environments. Without personal exposure data collected in partnership with workers, the true heat burden in these populations cannot be fully characterized and evidence-based occupational heat standards will be challenging to develop.

Cooking using biomass is ubiquitous; the burdens of fuel collection and household air pollution exposure impose physical, social, economic, and environmental costs on women and children. We will design, refine, and test implementation strategies to promote purchase and use of electric induction stoves – arguably the cleanest household cooking solution – among low-income households in peri-urban Cambodia. Our goal is to provide actionable strategies to achieve sustainable access to and use of induction stoves.

We have assembled a strong team to lead this work, with expertise in implementation studies, mixed methods, exposure assessment, epidemiology, and trial design and execution. Our team is based at Rollins School of Public Health at Emory University, UC Berkeley’s School of Public Health, University of South Carolina, and iDE Cambodia and Global.

The proposed study will evaluate the effectiveness of a health-focused community program transitioning low-income and health-vulnerable populations from gas to induction cooking, aiming to reduce exposure to household air pollution. The study will conduct exposure assessments, build a comprehensive database of personal and kitchen air pollutant concentrations, and apply a rigorous stepped-wedge design across 300 homes. It will provide detailed exposure estimates linked to cooking behaviors and assess how ventilation practices affect exposure, with a focus on children, the most vulnerable to pollutants. This research will expand environmental risk characterization by measuring a wide range of pollutants, including nitrogen dioxide (NO2), fine particulate matter (PM2.5) (including elemental composition), and Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) compounds. The overall goal of this study is to provide an empirical basis for guiding future intervention policies such as building ventilation and electrification in California. Informing these programmatic actions with sound scientific evidence will be critical to minimize exposure for California residents, and especially critical for energy-poor and vulnerable populations.

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.

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.

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.

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.

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 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.