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Air pollution in Africa is coming to the forefront and must not be ignored. For example, in South Africa the mercury levels are severe due to coal combustion and gold mining. Mercury is absorbed from the air into the soil and water. [19] The soil allows the crops to absorb the mercury, which humans ingest.
Physical weathering, also called mechanical weathering or disaggregation, is the class of processes that causes the disintegration of rocks without chemical change. Physical weathering involves the breakdown of rocks into smaller fragments through processes such as expansion and contraction, mainly due to temperature changes.
Declining soil quality is a food security concern across Africa. In Zimbabwe, once a regional breadbasket, about 70% of soils are acidic, according to the government.
There are a range of environmental issues in Southern Africa, such as climate change, land, water, deforestation, land degradation, and pollution.The Southern Africa region itself, except for South Africa, [1] produces less carbon emissions but is a recipient of climate change impacts characterized by changes in precipitation, extreme weather events and hot temperatures.
Soil erosion (especially from agricultural activity) is considered to be the leading global cause of diffuse water pollution, due to the effects of the excess sediments flowing into the world's waterways. The sediments themselves act as pollutants, as well as being carriers for other pollutants, such as attached pesticide molecules or heavy metals.
Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste .
The causes of desertification are a combination of natural and human factors, with climate change exacerbating the problem. Despite this, there is a common misconception that desertification in Africa is solely the result of natural causes like climate change and soil erosion.
Desertification is a gradual process of increased soil aridity.Desertification has been defined in the text of the United Nations Convention to Combat Desertification (UNCCD) as "land degradation in arid, semi-arid and dry sub-humid regions resulting from various factors, including climatic variations and human activities."