how does air get polluted?
Air pollution is usually a result of human activity. The main causes of human air pollution is from cars, waste disposal and industry. However air can also be polluted from natural processes, like volcanic activity which releases various pollutants like sulphur for example. Other natural pollutants include carbon monoxide an dioxide from wildfires, and as the other guy said, radon from radioactive decay within the earths crust.
hope i mde it clear...THUMBS UP