Air Quality in India

Air pollution in South Asia - especially across the Indo-Gangetic basin in Northern India, Pakistan, Nepal, and Bangladesh - ranks among the most severe in the world. In India alone, hundreds of millions of people are exposed to PM2.5 concentrations an order of magnitude greater than World Health Organization guidelines. However, fundamental aspects of our understanding of particle air pollution in India are incomplete. To inform policies to reduce exposures and improve public health, we are investigating the emissions and physicochemical processes that affect particle concentrations and composition. Our research includes field- and laboratory-based experiments and modeling studies.

Ambient fine particulate matter (PM_2.5) levels in Delhi, India rank among the highest levels routinely measured in any city in the world. Annual average PM_2.5 concentrations in Delhi are roughly 150 µg m^-3, or about 15 times higher than WHO guideline concentrations, and respectively 8× and 1.5× higher than levels in Los Angeles and Beijing. High PM_2.5 levels in Delhi are driven by a combination of unfavorable local meteorology and an unusually diverse mixture of local sources. PM sources in the Delhi area are numerous and incompletely understood, but include light- and heavy-duty vehicle traffic emissions and associated road dust, solid fuel combustion for heating and cooking, biomass and waste burning, thermal power plants, diesel generators, construction, and small-scale local industries (e.g., brick manufacturing).

Current research topics include: (i) chemical composition and source apportionment of ambient air pollution in Delhi, Bangalore, and across the Indo-Gangetic Plain, (ii) mobile monitoring to characterize pollution at high spatial resolution in Bangalore, and (iii) exploration of lower-cost sensing technologies for characterizing ambient air pollution.