Soil pollution is defined as the
presence of toxic chemicals in the ground high enough to endanger human and
ecosystem health in general concentrations. The contaminants are spilled on the
ground or buried under it, or permeate through the contaminated groundwater.
Acid rain resulting from air pollution can fall into the ground, contaminating
it. A farmer can use a source of contaminated water to irrigate crops,
polluting the water they depend on them to develop.
Human activities that contaminate
the soil are mining, chemical industry, livestock and agriculture, through the
intensive use of fertilizers and the application of sewage sludge to land. The
floor in a building can become contaminated due to the runoff of harmful
products used in construction. The painting, for example, is a source of lead
contamination.
Storage of waste in landfills can
also cause contaminants to reach groundwater, causing water pollution. The
pollutants that are in the soil can reach the plants and their fruits through
the roots. When humans and animals consume these plants and fruits, also
consume harmful elements.
Mining is one of the human
activities that contaminate the soil. In China large tracts of land are
contaminated with arsenic and heavy metals from mines and factories. Arsenic
that is released during the extraction of copper, gold and other minerals are increasingly
close to the surface. This contaminates any food that is grown in contaminated
soil.