关于某种环境问题的形成和危害及治理方式的介绍

Other planets have sunlight, but the Earth is the only planet we know that has air and water. Without air and water, the Earth would be unable to sustain life.

A diverse community of plant and animal life has thrived on this planet for millions of years, sustained by the sun and supported by the soil, water and air.

Definition of air pollution
Air pollution occurs when the air contains gases, dust, fumes or odour in harmful amounts. That is, amounts which could be harmful to the health or comfort of humans and animals or which could cause damage to plants and materials.

The substances that cause air pollution are called pollutants. Pollutants that are pumped into our atmosphere and directly pollute the air are called primary pollutants. Primary pollutant examples include carbon monoxide from car exhausts and sulfur dioxide from the combustion of coal.

Further pollution can arise if primary pollutants in the atmosphere undergo chemical