The Risk Assessment of Sediment Heavy Metal Pollution in the East Dongting Lake Wetland

Table 2

Heavy metal concentration in the sediment of the East Dongting Lake wetlands, geochemistry background of Dongting Lake, and Chinese environmental quality standard for soils.

	Cd	Cr	Ni	Pb
Sediment (mg kg^−1)
Background value (mg kg^−1)	0.23	83.92	41.86	27.75
National standards
Class I (mg kg^−1)	0.2	90	40	35
Class II (mg kg^−1)	0.6	350	60	350
Class III (mg kg^−1)	1	400	200	500