Air Pollution
Air Pollution · sources · NCAP · SAFAR · CPCB · graded action
12 min read · Updated 2026-05-25
What is Air pollution?
Air pollution is the presence of substances in the atmosphere at concentrations that harm health, ecosystems or materials. India measures six criteria pollutants — PM2.5, PM10, sulphur dioxide, nitrogen dioxide, carbon monoxide and ground-level ozone — against the National Ambient Air Quality Standards of 2009, and the National Clean Air Programme of 2019 targets a 40 per cent cut in particulate levels by 2026 across 131 cities.
The story
On 2 December 1984, methyl isocyanate (MIC) gas leaked from a Union Carbide plant in Bhopal, killing 3,787 people in one night and eventually 15,000+. That single catastrophe forced India to enact the Environment (Protection) Act, 1986 — the umbrella law under which air pollution is now regulated. Forty years later, on 2 December 2024, a different kind of air emergency unfolded: Delhi's AQI hit 494 — among the world's worst — schools were shut, GRAP Stage IV invoked, and the Supreme Court chastised state governments for failing to act on the Commission for Air Quality Management (CAQM) orders.
Bhopal was a one-night industrial accident. Delhi is a daily, slow-moving disaster: an estimated 1.67 million premature deaths annually in India from air pollution (Lancet Planetary Health, 2024) — more than from tobacco. The 2019 National Clean Air Programme (NCAP) set a goal of reducing PM2.5 and PM10 by 40 % by 2026. Halfway through, only 38 of 131 non-attainment cities have shown improvement.
This file walks through air pollutants and sources, the institutional architecture (CPCB, CAQM, SPCBs, SAFAR), the NCAP and GRAP frameworks, and the policy gap between the law on paper and the air in our lungs.
Why this matters for UPSC
Air pollution gets 1-2 Prelims MCQs per year on pollutant categories, AQI bands, NCAP targets, and the agencies. Mains often asks analytical questions on Delhi-NCR pollution, stubble burning, GRAP, and pollution governance. Interview boards probe value judgements — public health vs livelihoods.