Assessment of Heavy Metal Pollution Characteristics andEcological Risk in Soils around a Rare Earth Mine in Gannan

Table 7

Potential ecological risk index of the heavy metals in soils.

Sampling time	Projects	Comprehensive potential ecological risk index RI	Potential ecological hazard index
			Mn	Cu	Cr	As	Cd	Ni	Pb	Zn
High water period	Minimum value	31.00	0.67	1.17	0.21	1.08	8.33	0.90	6.60	0.72
	Maximum value	129.83	5.57	14.73	7.86	15.14	90.00	11.30	55.22	1.64
	Average	77.94	1.88	6.24	1.76	3.39	45.28	5.31	13.60	1.11
Withered water period	Minimum value	62.97	0.52	0.38	0.29	1.15	37.67	0.83	5.22	0.56
	Maximum value	203.60	4.57	13.74	4.11	13.79	180.33	9.80	31.30	1.65
	Average	118.15	1.94	5.43	1.58	3.52	86.23	4.85	13.75	1.05