Define atmospheric deposition in general and explain the causes and effects of acidic deposition

Question

What will be an ideal response?

Answer 1

Atmospheric deposition refers to the wet or dry deposition of a wide variety of pollutants, including mercury, nitrates, organochlorines, and many others. Acidic deposition refers to the deposition of acidic or acid-forming pollutants. This can take place either by precipitation (primarily acid rain, but also including acid snow, sleet, and hail), by fog, by gases, or by the deposition of dry particles. Acidic deposition originates primarily with sulfur dioxide and nitrogen oxides, pollutants produced largely through fossil fuel combustion by automobiles, electric utilities, and industrial facilities. Once emitted into the troposphere, these pollutants can react with water, oxygen, and oxidants to produce compounds of low pH. Droplets of these acids may travel hundreds or thousands of kilometers. Acidic deposition can have wide-ranging, cumulative detrimental effects on ecosystems and on our built environment. It leaches basic minerals such as calcium and magnesium from the soil, changing soil chemistry and harming plants and soil organisms. Streams, rivers, and lakes may become significantly acidified from runoff. Some forests in eastern North America have experienced widespread tree dieback from these conditions. Acidic precipitation also may damage stone buildings, eat away at cars, and erase the writing from tombstones.