Seasonal Transition in PM₁₀ Exposure and Associated All-Cause Mortality Risks in India

Lack of a consistent PM₁₀ (particulate matter smaller than 10 μm) database at high spatial resolution hinders in assessing the environmental impact of PM₁₀ in India. Here we propose an alternate approach to estimate the PM₁₀ database. Aerosol extinction coefficients at the surface are calculated from midvisible aerosol optical depth from MERRA-2 reanalysis data using characteristics vertical profiles from CALIOP and then are converted to PM₁₀ mass using aerosol property information and microphysical data. The retrieved PM₁₀ are bias-corrected and evaluated (<i>R</i>² = 0.85) against coincident ground-based data maintained under the Central Pollution Control Board network. PM₁₀ exposure exceeds Indian annual air quality standard in 72.3% districts. Transition in PM₁₀ exposure from the monsoon (Jun–Sep) to postmonsoon season (Oct–Nov) translates to 1–2% higher all-cause mortality risk over the polluted Indo-Gangetic Basin (IGB). Mortality risk increases in the central to eastern IGB and central India and reduces in Delhi national capital region in the winter (Dec–Feb) relative to the postmonsoon season. Mortality risk decreases by 0.5–1.8% in most parts of India in the premonsoon season (Mar–May). Our results quantify the vulnerability in terms of seasonal transition in all-cause mortality risks due to PM₁₀ exposure at district level for the first time in India