Aids + СПИД

n air contamination. The natural sources of contamination of an atmosphere are volcanos, wood fires, dusty storms, a weathering etc. These factors do not threaten with negative consequences to natural ecosystems, except some catastrophic natural phenomena. For example, the eruption of a volcano Cracatao in 1883, when into atmosphere 18 km cubes of ashes powder were thrown out ; eruption of a volcano Catmay (Alaska) in the 1912 that had thrown out 20 km cubes of friable products. The ashes of these eruptions were spread over large part of the surface of the Earth and has caused the reduction of