New research shows ammonium sulphate makes up nearly one-third of Delhi’s PM2.5 pollution and poses serious health risks.

As wildfire smoke blankets the East Coast, Air Quality Index and PM2.5 numbers are everywhere. Here’s what they mean. Air Quality Index, or AQI, and PM2.5, particulate matter which measures 2.5 ...

A big new study, with researchers from Harvard and CREA, just uncovered something troubling about Delhi’s air: almost a third ...

PM is also called Particulate Matter or particle pollution, which is a mixture of solid particles and liquid droplets present in the atmosphere. The particles present in the air are so minute that you ...

A CREA analysis reveals that 42% of India's PM2.5 pollution originates from secondary particulate matter, mainly ammonium ...

A 2025 Harvard-led study, conducted by researchers from Harvard TH Chan School of Public Health, found that sulfate particles ...

The Environmental Protection Agency’s emission factor resource, AP-42, is not your only option for developing particulate matter (PM) emission rates. Results of a prominent PM emissions measurement ...

New Delhi, A large share of India's PM2.5 pollution is not emitted directly but is chemically formed in the atmosphere from precursor gases with 42 per cent of the burden being secondary particulate ...

A recent analysis by CREA uncovers that secondary particles from coal-fired power plants are the main driver of PM2.5 ...