Lead in the environment

TLDR

Lead is a highly toxic, soft, dense heavy metal that occurs in over 200 minerals and is naturally released into the environment through weathering, igneous activity, and radioactive decay. Anthropogenic emissions have raised soil and water lead concentrations to levels several orders of magnitude higher than natural background.

Abstract

Lead (Pb) is a nonessential, highly toxic heavy metal, whose known effects on biological systems are always deleterious. Lead is very soft (< 35 diamond pyramid hardness) and dense (11.34 g/cm) and occurs as an important constituent of more than 200 minerals. The average concentration in the earth’s crust is 0.016g Pb/kg soil,making it a relatively rare metal. Small amounts of lead are released into the environment by natural processes, including the weathering of rocks, igneous activity, and radioactive decay. Present anthropogenic lead emissions have resulted in soil and water lead concentrations up to several orders of magnitude higher than naturally occurring concentrations.