Contamination and Ecological Risk Assessment of Heavy Metals in Surface Sediments of Huangshui River, Northwest China

Table 4

Geoaccumulation index and pollution classification of heavy metals in sediments.

Site	Cr		As		Pb		Cd		Zn
	Igeo	Classification	Igeo	Classification	Igeo	Classification	Igeo	Classification	Igeo	Classification
S1	−0.73	0	4.30	5	1.35	2	4.92	5	−2.12	0
S2	−1.25	0	2.85	3	0.45	1	4.80	5	−4.12	0
S3	−0.35	0	4.34	5	1.54	2	4.46	5	−1.75	0
S4	−0.44	0	4.47	5	−0.11	0	4.42	5	−0.48	0
S5	−0.29	0	4.57	5	1.45	2	4.45	5	−2.75	0
S6	0.41	1	4.57	5	1.51	2	4.41	5	−1.82	0
S7	0.91	1	5.00	5	1.76	2	4.51	5	−4.35	0
S9	0.86	1	5.23	6	1.88	2	4.52	5	−4.55	0
S11	0.40	1	4.49	5	1.59	2	4.55	5	−5.44	0
S12	0.93	1	5.28	6	1.89	2	4.55	5	−5.10	0
S13	0.94	1	5.10	6	1.96	2	4.63	5	−4.43	0
S14	0.82	1	4.67	5	1.50	2	4.63	5	−5.33	0
S15	0.59	1	3.81	4	0.80	1	4.58	5	−6.23	0
S16	0.62	1	4.11	5	0.86	1	4.65	5	−6.38	0