Air environment is being polluted by toxic materials present in traffic smoke and industrial smoke.Road dust and burning of fuels in homes and furnaces also polluting the air.
Air pollution occurs when the air contains gases, dust, smoke from fires, or fumes in harmful amounts. Tiny atmospheric particles - aerosols - are a subset of air pollution that are suspended in our atmosphere.
Aerosol can be both solid and liquid. Most are produced by natural processes such as erupting volcanoes, and some are from human industrial and agricultural activities.
Aerosols have a measurable effect on climate change. Light-colored aerosol particles can reflect incoming energy from the sun in cloud-free air and dark particles can absorb it. Over the historic period, the net effect globally was for aerosols to partially offset the rise in global mean surface temperature. Aerosols can modify how much energy clouds reflect and they can change atmospheric circulation patterns.
Worldwide, most atmospheric aerosol particles are produced by natural processes such as grinding and erosion of land surfaces resulting in dust, salt-spray formation in oceanic breaking waves, biological decay, forest fires, chemical reactions of atmospheric gases, and volcanic injection.
Some particles, on the other hand, have human origins—industry, agriculture, transport (including aviation), and construction. The composition of atmospheric aerosol particles varies widely depending on their source—they may contain salts (predominantly sulfates), minerals (such as silicon), organic materials, and, in most cases, water.
The particles grow by absorbing water vapor and other gases. In moist air, clouds form when water vapor condenses onto these ‘cloud condensation nuclei’. These then grow into cloud drops, which eventually fall to the surface as rain or snow, depositing the particles on land or in the ocean