Ajay Pillarisetti

• Assistant Professor at Emory University

Emission factors of 16 particle-bound polycyclic aromatic hydrocarbons (16 p-PAHs) from residential fuel combustion are highly variable, resulting in significant uncertainty with respect to the estimation of emissions of PAHs from this sector. Emissions of 16 p-PAHs were characterized during daily cooking activities for two traditional Indian cooks...

Traditional gravimetric instruments used for personal air pollution exposure measurements are often cumbersome and noisy and do not offer real-time assessment capability. The Enhanced Children’s MicroPEM (ECM) is a comparatively lightweight and quiet instrument designed to capture both integrated filter-based gravimetric samples and real-time conti...

Exposure to household air pollution has been linked to adverse health outcomes among women aged 40–79. Little is known about how shifting from biomass cooking to a cleaner fuel like liquefied petroleum gas (LPG) could impact exposures for this population. We report 24-h exposures to particulate matter (PM2.5), black carbon (BC), and carbon monoxide...

Background Air pollution may impair child growth and cognitive development, with potential markers including birth length and head circumference. Methods The Household Air Pollution Intervention Network (HAPIN) trial was an open label multi-country-randomized controlled trial, with 3200 pregnant women aged 18–34 years (9–19 weeks of gestation) ran...

The use of liquefied petroleum gas (LPG), a World Health Organization (WHO)-designated “clean” fuel, dominates household fuel expansion in low- and middle-income countries. This is due largely to support by the oil and gas industry, government policies, and claims of health and climate benefits over traditional biomass. However, recent randomized c...

Background Household air pollution (HAP) is a leading environmental risk factor accounting for about 1.6 million premature deaths mainly in low- and middle-income countries (LMICs). However, no multicounty randomized controlled trials have assessed the effect of liquefied petroleum gas (LPG) stove intervention on HAP and maternal and child health o...

Households that burn biomass in inefficient open fires—a practice that results in $1.6 trillion in global damages from health impacts and climate-altering emissions yearly—are often unable to access cleaner alternatives, like gas, which is widely available but unaffordable, or electricity, which is unattainable for many due to insufficient supply a...

Background Anemia is common in low- and middle-income countries (LMICs), causing significant health issues and social burdens. Exposure to household air pollution from using biomass fuels for cooking and heating has been associated with anemia, but the exposure–response association has not been studied. Objectives We evaluated the associations bet...

Background Household air pollution might lead to fetal growth restriction during pregnancy. We aimed to investigate whether a liquefied petroleum gas (LPG) intervention to reduce personal exposures to household air pollution during pregnancy would alter fetal growth. Methods The Household Air Pollution Intervention Network (HAPIN) trial was an ope...

Background: An estimated 3 billion people, largely in low- and middle-income countries, rely on unclean fuels for cooking, heating, and lighting to meet household energy needs. The resulting exposure to household air pollution (HAP) is a leading cause of pneumonia, chronic lung disease, and other adverse health effects. In the last decade, randomiz...

Background Household air pollution exposure is a risk factor for severe pneumonia. The effect of replacing biomass cooking with liquefied petroleum gas (LPG) cookstoves on severe infant pneumonia is uncertain. Methods We conducted a randomized controlled trial among 3,200 pregnant women aged 18-34 years and 9 to <20 weeks gestation in India, Guate...

Background: Household air pollution is associated with stunted growth in infants. Whether the replacement of biomass fuel (e.g., wood, dung, or agricultural crop waste) with liquefied petroleum gas (LPG) for cooking can reduce the risk of stunting is unknown. Methods: We conducted a randomized trial involving 3200 pregnant women 18 to 34 years o...

Exposure to heat is associated with a substantial burden of disease and is an emerging issue in the context of climate change. Heat is of particular concern in India, which is one of the world’s hottest countries and also most populous, where relatively little is known about personal heat exposure, particularly in rural areas. Here, we leverage dat...

We use three quantitative case studies to argue that ubiquitous and universal condemnation of fossil fuel subsidies is myopic and does not adequately consider subsidizing gas for cooking as a potential strategy to improve public health and reduce greenhouse gas emissions. Ecuador offers a view into the long-run impacts of gas subsidies, having made...

Lower-cost air pollution sensors can fill critical air quality data gaps in India, which experiences very high fine particulate matter (PM2.5) air pollution but has sparse regulatory air monitoring. Challenges for low-cost PM2.5 sensors in India include high-aerosol mass concentrations and pronounced regional and seasonal gradients in aerosol compo...

Background: Reducing household air pollution (HAP) to levels associated with health benefits requires nearly exclusive use of clean cooking fuels and abandonment of traditional biomass fuels. Methods: The Household Air Pollution Intervention Network (HAPIN) trial randomized 3,195 pregnant women in Guatemala, India, Peru, and Rwanda to receive a...

Exposure to household air pollution is a leading cause of ill-health globally. The Household Air Pollution Intervention Network (HAPIN) randomized controlled trial evaluated the impact of a free liquefied petroleum gas stove and fuel intervention on birth outcomes and maternal and child health. As part of HAPIN, extensive exposure assessment was co...

Background: Reducing household air pollution (HAP) to levels associated with health benefits requires nearly exclusive use of clean cooking fuels and abandonment of traditional biomass fuels. Methods: The Household Air Pollution Intervention Network (HAPIN) trial randomized 3,195 pregnant women in Guatemala, India, Peru, and Rwanda to receive a liq...

Household air pollution from solid cooking fuel use during gestation has been associated with adverse pregnancy and birth outcomes. The Household Air Pollution Intervention Network (HAPIN) trial was a randomized controlled trial of free liquefied petroleum gas (LPG) stoves and fuel in Guatemala, Peru, India, and Rwanda. A primary outcome of the mai...

Background: Household air pollution (HAP) from solid fuel use is associated with adverse birth outcomes, but data for exposure-response relationships are scarce. We examined associations between HAP exposures and birthweight in rural Guatemala, India, Peru, and Rwanda during the Household Air Pollution Intervention Network (HAPIN) trial. Methods:...

Background: Nationwide household transitions to the use of clean-burning cooking fuels are a promising pathway to reducing under-5 lower respiratory infection (LRI) mortality, the leading cause of child mortality globally, but such transitions are rare and evidence supporting an association between increased clean fuel use and improved health is l...

We report on the long-term performance of a popular low-cost PM2.5 sensor, the PurpleAir PA-II, at multiple sites in India, with the aim of identifying robust calibration protocols. We established 3 distinct sites in India (North India: Delhi, Hamirpur; South India: Bangalore), where we collocated PA-II with reference beta-attenuation monitors to c...

Direct exposure to household fine particulate air pollution (HAP) associated with inefficient combustion of fuels (wood, charcoal, coal, crop residues, kerosene, etc.) for cooking, space-heating, and lighting is estimated to result in 2.3 (1.6–3.1) million premature yearly deaths globally. HAP emitted indoors escapes outdoors and is a leading sourc...

Low-cost air quality (LCAQ) sensors are increasingly being used for community air quality monitoring. However, data collected by low-cost sensors contain significant noise, and proper calibration of these sensors remains a widely discussed, but not yet fully addressed, area of concern. In this study, several LCAQ sensors measuring nitrogen dioxide...

Cooking and heating using solid fuels can result in dangerous levels of exposure to household air pollution (HAP). HAPIN is an ongoing randomized controlled trial assessing the impact of a liquified petroleum gas stove and fuel intervention on HAP exposure and health in Guatemala, India, Peru, and Rwanda among households that rely primarily on soli...

COVID-19 continues to exact a substantial toll on health. While mortality and morbidity associated with the pandemic are the most obvious impacts, social and economic disruptions are becoming apparent. There is reason to believe that the COVID-19 pandemic has slowed or reversed gains in clean household energy use in rural India. Here we describe ph...

Here, we present a visual representation of standard procedures to collect population level data on personal exposures to household air pollution (HAP) from two different study sites in a resource-constrained setting of Tamil Nadu, India. Particulate matter PM2.5 (particles smaller than 2.5 microns in aerodynamic diameter), carbon monoxide (CO), an...

Household air pollution resulting from solid fuel combustion is a leading cause of global morbidity and mortality. Strategies to measure area concentrations of and exposures to PM2.5 in rural homes focus primarily on short-term measurements, often of 24 or 48 h. Little is known about how well these short-term measurements, commonly used exposure me...

Exposure to heat is associated with a substantial burden of disease and is an emerging issue in the context of climate change. Heat exposure is of particular concern in India, one of the world's hotter countries and soon to be its most populous, where a large fraction of the population works outdoors, lives in dwellings that are thermally inefficie...

Women and children in rural regions of low-income countries are exposed to high levels of household air pollution (HAP) as they traditionally tend to household chores such as cooking with biomass fuels. Early life exposure to air pollution is associated with aeroallergen sensitization and developing allergic diseases at older ages. This prospective...

Background: Exposure during pregnancy to household air pollution caused by the burning of solid biomass fuel is associated with adverse health outcomes, including low birth weight. Whether the replacement of a biomass cookstove with a liquefied petroleum gas (LPG) cookstove would result in an increase in birth weight is unclear. Methods: We perf...

Background: Exposure to PM2.5 arising from solid fuel combustion is estimated to result in ∼2.3 million premature deaths and 91 million lost disability-adjusted life years annually. Interventions attempting to mitigate this burden have had limited success in reducing exposures to levels thought to provide substantive health benefits. Objectives:...

Much of the global population spends most of their time indoors; however, air pollution measurement, a proxy of exposure, occurs primarily outdoors. This fundamental disconnect between where the people are and where the measurements are made likely leads to misestimation of the true burden of air pollution on human health, which is already substant...

Background Household air pollution (HAP) from solid fuel use is associated with adverse birth outcomes, but data on exposure-response relationships are limited. We examined associations between HAP exposures and birthweight in rural Guatemala, India, Peru, and Rwanda during the Household Air Pollution Intervention Network (HAPIN) trial. Methods We...

Elevated blood pressure (BP) is a leading risk factor for the global burden of disease. Household air pollution (HAP), resulting from the burning of biomass fuels, may be an important cause of elevated BP in resource-poor communities. We examined the exposure-response relationship of personal exposures to HAP —fine particulate matter (PM2.5), carbo...

Anaemia remains an intransigent global health problem that increases the risk of morbidity and mortality for women and children, and nowhere more so than in India. Now, a study links particulate air pollution exposure with anaemia in women of reproductive age.

Background: Approximately 3 to 4 billion people worldwide are exposed to household air pollution, which has been associated with increased blood pressure (BP) in pregnant women in some studies. Methods: We recruited 3195 pregnant women in Guatemala, India, Peru, and Rwanda and randomly assigned them to intervention or control groups. The interve...

Background The Household Air Pollution Intervention Network (HAPIN) trial is an ongoing multi-center randomized controlled trial assessing the impact of a liquified petroleum gas (LPG) cookstove and fuel intervention on health. Given the potential impacts of household air pollution (HAP) exposure from burning solid fuels on cardiovascular health du...

The Tamil Nadu Air Pollution and Health Effects study (TAPHE-2) aims to evaluate the relationship between air pollution and birth outcome in a rural-urban cohort of 300 pregnant women. Due to COVID-19 related lockdowns, some TAPHE-2 activities were delayed; however, continuous indoor and outdoor air quality data were collected in and around Chennai...

Background: Ambient fine particulate matter [PM ≤2.5μm in aerodynamic diameter (PM2.5)] is a major health risk for children, particularly in South Asia, which currently experiences the highest PM2.5 levels globally. Nevertheless, there is comparatively little epidemiological evidence from this region to quantify the effects of PM2.5 on child survi...

Background: Clean cookstove interventions can theoretically reduce exposure to household air pollution and benefit health, but this requires near-exclusive use of these types of stoves with the simultaneous disuse of traditional stoves. Previous cookstove trials have reported low adoption of new stoves and/or extensive continued traditional stove...

Background: Clean cookstove interventions can theoretically reduce exposure to household air pollution and benefit health, but this requires near-exclusive use of the stoves, with simultaneous disuse of traditional stoves. Previous cookstove trials have reported low adoption of new stoves and/or extensive continued traditional stove use. Methods: T...

Background Exposure to PM 2.5 arising from solid fuel combustion is estimated to result in approximately 2.3 million premature deaths and 90 million lost disability-adjusted life years annually. ‘Clean’ cooking interventions attempting to mitigate this burden have had limited success in reducing exposures to levels that may yield improved health ou...

The Household Air Pollution Intervention Network trial is a multi-country study on the effects of a liquefied petroleum gas (LPG) stove and fuel distribution intervention on women's and children's health. There is limited data on exposure reductions achieved by switching from solid to clean cooking fuels in rural settings across multiple countries....

The Pradhan Mantri Ujjwala Yojana (PMUY), launched in India in 2016, is the world's largest program to provide cleaner cooking fuel to poor households. The PMUY may yield large health benefits because of increased LPG use, and more importantly, reduced chulha use, and thus may significantly reduce household air pollution exposures. This research, c...

The World Health Organization and the United States Centers for Disease Control have recommended universal face masking by the general public to slow the spread of COVID-19. A number of recent studies have evaluated the filtration efficiency and pressure differential (an indicator of breathability) of various, widely available materials that the ge...

Background Household air pollution adversely affects human health and the environment, yet more than 40% of the world still depends on solid cooking fuels. The House Air Pollution Intervention Network (HAPIN) randomized controlled trial is assessing the health effects of a liquefied petroleum gas (LPG) stove and 18-month supply of free fuel in 3,20...

This study assessed the performance of modeling approaches to estimate personal exposure in Kenyan homes where cooking fuel combustion contributes substantially to household air pollution (HAP). We measured emissions (PM2.5, black carbon, CO); household air pollution (PM2.5, CO); personal exposure (PM2.5, CO); stove use; and behavioral, socioeconom...

Clean cooking energy strategies are critical for reducing air pollution, improving health, and achieving related Sustainable Development Goals. The recent COVID-19 lockdowns may impact the transition towards clean cooking fuels. The nationwide lockdown is likely to affect key factors such as energy access, income, transportation, etc., that play a...

Introduction: The coronavirus disease 2019 (COVID-19) pandemic has caused a global shortage of single-use N95 filtering facepiece respirators (FFRs). A combination of heat and humidity is a promising method for N95 FFR decontamination in crisis-capacity conditions; however, an understanding of its effect on viral inactivation and N95 respirator fun...

Introduction: The COVID-19 pandemic has led to critical shortages of single-use N95 filtering facepiece respirators. The US Centers for Disease Control and Prevention has identified ultraviolet-C (UV-C) irradiation as one of the most promising decontamination methods during crisis-capacity surges; however, understanding the mechanism of pathogen in...

BACKGROUND: Inadequate access to safe drinking water remains a global health problem, particularly in rural areas. Boiling is the most commonly used form of point-of-use household water treatment (HWT) globally, although the use of bottled water in low-and middle-income countries (LMICs) is increasing rapidly. OBJECTIVES: We assessed the regional...

In India, approximately 480,000 deaths occur annually from exposure to household air pollution from the use of biomass cooking fuels. Displacing biomass use with clean fuels, such as liquefied petroleum gas (LPG), can help reduce these deaths. Through government initiatives, most Indian households now own an LPG stove and one LPG cylinder. Many hou...

Background The Household Air Pollution Intervention Network (HAPIN) trial aims to assess health benefits of a liquefied petroleum gas (LPG) cookfuel and stove intervention among women and children across four low- and middle-income countries (LMICs). We measured exposure contrasts for women, achievable under alternative conditions of biomass or LPG...

Household air pollution (HAP) generated from solid fuel combustion is a major health risk. Direct measurement of exposure to HAP is burdensome and challenging, particularly for children. In a pilot study of the Household Air Pollution Intervention Network (HAPIN) trial in rural Guatemala, we evaluated an indirect exposure assessment method that emp...

Introduction: Health interventions often target pregnant women and their unborn children. Interventions in rural India targeting pregnant women, however, often do not cover the critical early windows of susceptibility during the first trimester and parts of the second trimester. This pilot seeks to determine if targeting newlyweds could protect en...

Aside the emissions, burning of wood in traditional cookstoves (TCs) also generates substantial amount of ash containing hazardous pollutants such as polycyclic aromatic hydrocarbons (PAHs) and toxic metals. But, their concentrations in the ash, particularly in Africa where over 70% of the population utilize TCs, remain unknown. Here, we determined...

Stove stacking (concurrent use of multiple stoves and/or fuels) is a poorly quantified practice in regions with ongoing efforts to transition household energy to cleaner options. Using biomass-burning stoves alongside clean stoves undermines health and environmental goals. This review synthesizes stove stacking data gathered from eleven case studie...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Background: High quality personal exposure data is fundamental to understanding the health implications of household energy interventions, interpreting analyses across assigned study arms, and characterizing exposure-response relationships for household air pollution. This paper describes the exposure data collection for the Household Air Pollutio...

Researchers rely on sensor-derived data to gain insights on numerous human behaviors and environmental characteristics. While commercially available data-logging sensors can be deployed for a range of measurements, there have been limited resources for integrated hardware, software, and analysis platforms targeting field researcher use cases. In th...

Assessment of personal exposure to PM2.5 is critical for understanding intervention effectiveness and exposure‐response relationships in household air pollution studies. In this pilot study, we compared PM2.5 concentrations obtained from two next‐generation personal exposure monitors (the Enhanced Children MicroPEM or ECM; and the Ultrasonic Person...

Exposure to harmful by-products of combustion arising from the use of biomass fuels for cooking and heating in rural areas of developing countries results in poor air quality and is responsible for millions of deaths yearly. Little formal quantification and measurement of carbon monoxide (CO), one of these harmful air pollutants, have been performe...

Pneumonia is a leading killer of children younger than 5 years despite high vaccination coverage, improved nutrition, and widespread implementation of the Integrated Management of Childhood Illnesses algorithm. Assessing the effect of interventions on childhood pneumonia is challenging because the choice of case definition and surveillance approach...

Approximately 3 billion people worldwide cook with solid fuels, such as wood, charcoal, and agricultural residues. These fuels, also used for residential heating, are often combusted in inefficient devices, producing carbonaceous emissions. Between 2.6 and 3.8 million premature deaths occur as a result of exposure to fine particulate matter from th...

Household air pollution from the combustion of biomass and coal is estimated to cause approximately 780,000 premature deaths a year in India. The government has responded by promoting uptake of liquefied petroleum gas (LPG) by tens of millions of poor rural families. Many poor households with new LPG stoves, however, continue to partially use tradi...

Executive Summary What is the single largest source of air pollution exposure in India? You would be perhaps surprised to find that the answer, with a near consensus in the published scientific literature, is neither transportation nor stubble burning. Instead, it seems to be the millions of households across the country burning solid fuels like fi...