Air pollution exposure is the second most important risk factor for ill health in South Asia, contributing to between 13% and 21.7% of all deaths and approximately 58 million disability adjusted life years (DALYs) through chronic and acute respiratory and cardiovascular illnesses.1 Of the top 30 cities in the world with the poorest air quality in 2016, 17 are in South Asia.2 The impact of air pollution transcends boundaries. The “brown cloud”—caused by pollution from carbon aerosols—is a phenomenon captured in satellite images of atmospheric haze over South Asia, as well as China.

Household air pollution from use of solid fuels is a major contributor to the national burden of disease in India. Currently available models of advanced combustion biomass cook-stoves (ACS) report significantly higher efficiencies and lower emissions in the laboratory when compared to traditional cook-stoves, but relatively little is known about household level exposure reductions, achieved under routine conditions of use. We report results from initial field assessments of six commercial ACS models from the states of Tamil Nadu and Uttar Pradesh in India.