Table 1.

Statistical characteristics for potential toxic elements in in the study area (mg·kg⁻¹).

	As	Cd	Cr	Cu	Mn	Ni	Pb	Zn	Ba
Minimum	17.42	0.06	231.15	22.72	260.53	103.13	289.12	55.65	204.52
Mean	22.55	0.32	1222.21	43.47	628.97	282.84	339.86	137.55	614.63
Maximum	39.19	0.78	6558.27	90.88	936.77	541.28	373.70	319.11	1040.48
Standard deviation	4.54	0.17	1726.00	15.99	134.70	104.45	23.64	77.18	206.10
Coefficient of variation	0.20	0.54	1.41	0.37	0.21	0.37	0.07	0.56	0.34
Background value	12.3	0.17	86	30.7	712	37.3	26.7	83.6	469
Risk screening value	20	20	–	2000	–	150	400	–	–
Grade II	40	0.30	150	50	–	40	250	200	–