Human Health Risk Assessment of Heavy Metals in Groundwater in the Luan River Catchment within the North China Plain

Table 4

The carcinogenic risks and HQs of Cd, Ni, and Cr in different periods.

Heavy metals	Period	Carcinogenic risk			Hazard Quotient
		Max	Min	Average	Max	Min	Average
Cd	First
	Second
	Third
	Fourth				4.644	0.422	1.604
	Fifth
	Sixth
	Seventh
	Eighth
Ni	First				3.419	0.694	1.704
	Second				3.082	0.832	1.682
	Third				3.061	0.842	1.716
	Fourth				4.433	0.766	1.722
	Fifth				2.828	0.515	1.455
	Sixth				1.549	0.369	0.789
	Seventh				1.395	0.191	0.641
	Eighth				1.501	0.168	0.682
Cr	First				2.744	0.041	1.009
	Second				6.121	0.566	2.555
	Third				0.395	0.063	0.223
	Fourth				5.699	0.779	1.878
	Fifth				6.332	0.475	1.703
	Sixth				9.161	1.055	2.824
	Seventh				5.383	0.884	2.178
	Eighth				4.496	0.716	2.371