Soil pollution is caused by a variety of anthropogenic activities, but mining activities, chemical spills and improper disposal of toxic chemicals are the most common causes. Some contaminants, including salts, metals and alcohols, are present in the soil naturally. However, if these chemicals build up to toxic levels, they may become a natural form of soil pollution.
Virtually any mining, construction or manufacturing activities can contribute to soil pollution. Typically, the government or local municipality designates how such industries dispose of pollutants. However, in addition to the inevitability of accidents that expose the soil to harmful chemicals, some businesses may choose to dump their waste products improperly, contributing further to the problem.
In addition to these industries, the transportation of the chemicals they use is a dangerous activity. If the transporting vehicle becomes involved in an accident, pollutants may be dispursed over a large area. This can cause a very severe problem for the local habitats.
Polluted rain can also cause soil pollution. As the rain comes down from the clouds laden with toxic chemicals, the water covers the ground. While the water runs off or evaporates, the pollutants are often left behind. Over time, they can accumulate in toxic quantities.