Table 6.

Descriptive statistics of geochemical indices

	Cd	Cr	Cu	Hg	Ni	Pb	Zn
Geoaccumulation index
Mean	1.97	1.09	− 0.70	− 0.08	− 0.54	0.35	0.36
Median	1.90	1.16	− 0.78	− 0.45	− 0.62	0.25	0.33
Standard deviation	0.30	0.54	0.78	1.43	0.42	0.61	0.84
Variation coefficient	0.15	0.50	− 1.10	− 17.76	− 0.77	1.74	2.29
Share of polluted samples1	40.7%	7.7%	0%	8.8%	0%	4.4%	4.4%
Enrichment factor
Mean	5.39	2.96	0.91	2.51	0.88	1.83	1.99
Median	5.10	3.04	0.83	1.08	0.89	1.64	1.73
Standard deviation	3.19	1.33	0.57	4.35	0.19	1.09	1.52
Variation coefficient	0.59	0.44	0.62	1.73	0.21	0.59	0.76
Share of polluted samples1	52.7%	3.3%	0%	9.9%	0%	3.3%	5.5%
Ecological risk factor
Mean	181.28	6.88	5.26	111.17	5.36	10.74	2.31
Median	168.6	6.70	4.35	43.71	4.85	8.93	1.89
Standard deviation	41.94	2.73	2.99	194.68	1.81	7.00	1.76
Variation coefficient	0.23	0.39	0.56	1.75	0.33	0.65	0.76
Share of polluted samples1	91 (100%)	0 (0%)	0 (0%)	54 (59.3%)	0 (0%)	2 (2.2%)	0 (0%)

¹share of samples (%), for which specific index is above the level “not polluted”