The urban haze that we call smog contains pollutants that react to form ozone. Most of the pollutants that form ozone come from cars. Large factories account for another portion of the emissions. Small businesses such as printing plants, service stations, and auto body shops, and people using lawnmowers, paints, and cleaning solvents account for another portion of the emissions. Asthma Air Toxics Toxic air pollutants are poisonous substances in the air that come from natural sources or from manmade sources and can harm the environment or your health.
Some health problems occur very soon after a person inhales a toxic air pollutant.
PM comes from a variety of sources, such as smokestacks and cars, dust from unpaved roads and construction activities, woodstoves or the mixing of chemical compounds in the air. PM less than 10 micrometers in size, can penetrate deep into the lungs. On a smoggy day, one can inhale millions of particles in a single breath. People most at risk from exposure to fine particulate matter area children, the elderly, and people with chronic respiratory problems. These updated public health standards address significant, real world, quality of life issues for the American public.