Air pollution occurs when chemical, physical or biological substances alter the natural characteristics of the atmosphere, potentially leading to respiratory and other diseases that can be lethal. Home furnaces, automobiles, industrial plants, and forest fires are the main sources of air pollution worldwide.Among the pollutants of greatest public health concern are particulate matter-including some forms of smoke, soot, dust, salt, acids, and metals - carbon monoxide, ozone, nitrogen dioxide, and sulfur dioxide. Not all air pollution is manmade. Natural weather events, such as hurricanes, can also significantly deteriorate air quality, for example. Hurricane-force winds stir up dust throughout the affected areas, including particular matter including in the ranges most harmful to humans, from 2.5 micrometers (PM2.5) to 10 micrometers (PM10)*.
The International Agency for Research on Cancer (IARC) at the World Health Organization classifies particulate matter, the main component of...