Nitrate portion of PM2.5-PRI

NOx from vehicles, power plants, and industry combining with ammonia from fertilizers and animal operations to form ammonium nitrate, especially in cool, stagnant air [1][2].

Breathing outdoor air—higher near busy roads or downwind of farms—and indoor air as particles seep inside homes, schools, and vehicles [1][2].

Short- and long-term PM2.5 exposure is linked to asthma attacks, reduced lung function, heart attacks, strokes, hospitalizations, and early death; outdoor PM and PM2.5 are classified as carcinogenic to humans [1][2][3].

Children, older adults, pregnant people, those with asthma, COPD, heart disease, or diabetes, outdoor workers, and people living near traffic or agricultural sources [1][2].

Check the Air Quality Index, limit strenuous outdoor activity on high-PM days, choose routes away from heavy traffic, use a HEPA air cleaner, keep windows closed, use recirculate in vehicles, and consider a well-fitted N95 when pollution is high [1][2][4].