India’s decision in mid-2025 to relax emission standards for sulphur dioxide (SO₂) from coal-fired power plants exempting nearly 78% of thermal units has triggered renewed alarm over air pollution and public health vulnerability.

Despite a gradual decline in ambient SO₂ levels over the past decade, India remains the world’s largest SO₂ emitter, with coal-based power plants responsible for around 60% of the emissions. This rollback overturns earlier 2015 regulations meant to safeguard air quality.

SO₂ not only irritates the respiratory system but also forms harmful particulate matter (PM₂.₅ and PM₁₀) that penetrates deep into lungs. Persistent exposure can worsen asthma, cardiovascular disease, and may reduce life expectancy. SO₂’s secondary forms also contribute to acid rain, damaging crops, ecosystems, and soil health.

Regional reports highlight hotspots: in Punjab, coal plants emit nine times more SO₂ than seasonal crop burning; in Maharashtra, most thermal units bypass flue gas desulphurisation systems, intensifying local air quality risks.

Advocates warn this policy reversal undermines the National Clean Air Programme (NCAP) and public health goals. Without FGD installation, India risks stalling progress in PM reduction, while denying industrial opportunities to reuse by-products like gypsum.