Overview

• The peer-reviewed analysis, published August 29, 2025 in the American Journal of Respiratory and Critical Care Medicine, was supported by NIH and NIEHS grants.
• For each decile increase in the pollutant mixture, hospitalization risk rose 10.6% among children and 8% among adults ages 19–64.
• Weighted quantile sum regression apportioned mixture effects, highlighting nickel, vanadium, sulfate, nitrate, bromine, and ammonium as the heaviest contributors.
• Fuel-oil combustion likely drives nickel and vanadium, coal burning produces sulfates, and recommended controls include scrubbers, cleaner fuels, and removing metal contaminants from oil.
• The study linked machine-learning estimates of 15 PM2.5 components to hospital records from 11 states covering 2002–2016, and the authors called for further research on short-term exposure effects.