At ground level it is a pollutant with toxic effects. Can also damage trees and plants and reduce visibility. Nitrogen oxides react with volatile organic compounds to form smog. Produced from burning fuels, including gasoline and coal. Aside from reducing visibility and soiling clothing, microscopic particles in the air can be breathed into lung tissue becoming lodged and causing increased respiratory disease and lung damage.
Particulates are also the main source of haze, which reduces visibility.
Produced by burning coal, most notably in power plants. Major contributor to smog and acid rain. Synthesized and concentrated. Many released from burning fuel, such as gasoline, wood, coal, natural gas and from solvents, paints, glues, and other products. Better Cars, More Driving v Emissions from vehicles have been reduced by a factor of 8 times since the late 1960s through legislative effort.