Heavy Metals in Contaminated Soils: A Review of Sources, Chemistry, Risks and Best Available Strategies for Remediation

Table 1

Soil concentration ranges and regulatory guidelines for some heavy metals.

Metal	Soil concentration range^†	Regulatory limits^‡
	(mg kg^−1)	(mg kg^−1)
Pb	1.00–69 000	600
Cd	0.10–345	100
Cr	0.05–3 950	100
Hg	<0.01–1 800	270
Zn	150–5 000	1 500

^†[64]; ^‡Nonresidential direct contact soil clean-up criteria [65].