Soil pollution can have significant deleterious consequences for ecosystems. Dramatic changes in soil chemistry can occur which can result from many hazardous chemicals even at low concentrations of pollutant species. These changes can manifest themselves in the alteration of the metabolism of the microorganisms and arthropods that live in a given land environment. The result may be the eventual eradication of a part of the primary food chain, which in turn has the greatest consequences on predators or consumer species.
Although the effects of chemicals on lower life forms may be minor, there is usually a bioaccumulation that tends to concentrate the same amount of substances further up the food chain. Many of these effects are well known, such as the accumulation of DDT in avian consumers leading to the weakening of eggshells, resulting in increased chick mortality and potential risk of species extinction.
The effects are also manifested on land used for agriculture and which are affected by a given level of pollution. Pollutants typically alter plant metabolism, the most common result of which is decreased crop yield. This represents a secondary effect on soil conservation, given that the decrease in harvests favors erosion phenomena.
Some of the chemical contaminants have a long persistence, while in other cases chemical compounds are formed as a result of secondary reactions that take place in the soil itself. Within a short time, the so-called megacities of many millions of inhabitants arose, which still do not have an adequate organization for waste disposal.
In fact, unlike for industries, for urbanization it is not yet possible to reach tangible solutions to the disorderly growth of the population and to the formation of temporary urban agglomerations devoid of any hygienic measures.
These drawbacks, in addition to the danger of diseases, also lead to an excessive biological load of watercourses, soil pollution by various wastes and therefore also the contamination of groundwater and profound environmental degradation.
Another type of soil pollution is the radioactive one deriving from accidents at nuclear power plants as demonstrated by the long-term local consequences produced by the Chernobyl and Fukushima disasters, the only two civilian nuclear accidents to reach the maximum degree of the INES scale.