Soil pollution or soil contamination as part of land degradation is caused by the presence of xenobiotic (man-made) chemicals or other alterations in the natural soil environment. It is usually caused by industrial activity, agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons (such as naphthalene and benzo (a) pyrene), solvents, pesticides, lead and other heavy metals. Pollution is correlated with the degree of industrialization and the intensity of the use of chemical products.
The concern for soil contamination comes mainly from health risks, direct contact with contaminated soil, vapors from pollutants and secondary contamination of water supplies in and below the ground. The mapping of contaminated soil sites and the resulting cleanings are costly and time-consuming tasks, requiring large amounts of geology, hydrology, chemistry, computational modeling skills and GIS in Environmental Pollution, as well as an appreciation of the history of chemistry industrial.
In North America and Western Europe, the extent of contaminated land is the best known, and many countries in these areas have a legal framework to identify and address this environmental problem. Developing countries tend to be less regulated despite the fact that some of them have experienced significant industrialization.