Soil and Water Contamination by Heavy Metals

This chapter attempts to summarize information on background levels of metals in soils and waters, anthropogenic sources of metals to soil and water systems, important soil processes which dictate the mobility and bioavailability of metals, and contamination of different water systems with heavy metals. Anthropogenic metal inputs are a major source of metal contamination of soils and waters. In spite of the vital importance of fertilizers and amendments for increased crop production, when used in large amounts they can cause contamination of soils and waters because they contain some undesired impurities such as heavy metals. Metal-containing sewage sludge when applied to agricultural soils can cause contamination of soils, crops, and waters because soil works as a dynamic entity through which metals pass during recycling from the waste to plants, water or air. Impact of mining and smelting activities on metal contamination of soils is extensively documented.