Table 4.

The concentrations of four heavy metals (Cd, Hg, Pb, Cr) in soil and rice grain from the Yangtze River of China.

Items	Soil				Rice Grain
	Cd	Hg	Pb	Cr	Cd	Hg	Pb	Cr
Number	101	101	101	101	101	101	101	101
Max (mg·kg−1)	4.64	1.46	127.56	231.02	1.81	0.09	0.68	93.74
Min (mg·kg−1)	0.10	0.01	7.64	13.52	0.01	0	0.12	0.23
Overall mean (mg·kg−1)	0.79	0.18	24.62	74.76	0.29	0.01	0.25	6.70
Standard deviation (mg·kg−1)	0.94	0.25	15.27	44.13	0.39	0.01	0.11	15.42
Median (mg·kg−1)	0.55	0.16	21.55	64.62	0.10	0.01	0.25	2.66
Percentage of excessive amount	70.90%	29.7%	0%	0%	37%	16%	60%	70%