Analysis of heavy-metal contaminants in soils and sludges

　　Soil: its contamination and regulation Soil is an important, but limited, resource essential for many human activities, including the production of food, raw materials and energy. One requirement of the sustainable management of soils is that they are protected from chemical contamination. Contamination can affect the fertility of soils as well as introducing toxic levels of metals (and other chemicals) to the human food chain.