Nearly Half of India PM2.5 Is Formed in the Air, Not Emitted Directly, CREA Study Finds
A significant share of India’s deadly PM2.5 pollution is not released directly from chimneys or vehicle exhausts but is chemically formed in the atmosphere from precursor gases, a new analysis by the Centre for Research on Energy and Clean Air has revealed. The findings challenge the country’s current air pollution control strategies, which largely focus on visible and primary emission sources.
According to the assessment, up to 42 per cent of India’s PM2.5 burden consists of secondary particulate matter, with ammonium sulphate emerging as the dominant component. This pollutant forms in the atmosphere when sulphur dioxide reacts with ammonia and other compounds, highlighting the crucial role of gaseous emissions rather than direct particle release.
India currently...








