The effects of the poisonous gasses and small particles in the atmosphere are very significant

An air pollutant is a material in the air that can have adverse effects on humans and the ecosystem.

Acid rain, precipitation possessing a pH of about 5.2 or below, are primarily produced from the emission of sulphur dioxide (SO2) and nitrogen oxides (NOx; the combination of NO and NO2) from human activities, mostly the combustion of fossil fuels. In acid-sensitive landscapes, acid deposition can reduce the pH of surface waters and lower biodiversity. It weakens trees and increases their susceptibility to damage from other stressors, such as drought, extreme cold, and pests. In acid-sensitive areas, acid rain also depletes soil of important plant nutrients and buffers, such as calcium and magnesium, and can release aluminum, bound to soil particles and rock, in its toxic dissolved form. Acid rain contributes to the corrosion of surfaces exposed to air pollution and is responsible for the deterioration of limestone and marble buildings and monuments.

The effects on humans

Estimates of the health impacts attributable to exposure to air pollution indicate that PM2. 5 concentrations in 2015 were responsible for about 422 000 premature deaths originating from long-term exposure in Europe, of which around 391 000 were in the EU-28.