Table 1.

Descriptive statistics of heavy metals in lake sediment and mean values of heavy metals in the upper continental crust (mg kg^‒1).

Heavy metal	Descriptive statistics	Pomacocha			Tipicocha			Tranca Grande			UCC
As	Range	2.94	−	3.78	6.44	−	7.56	4.48	−	4.90	1.5
	Mean ± SD	3.27	±	0.45	6.95	±	0.57	4.62	±	0.24
Cd	Range	0.17	−	0.172	0.17	−	0.19	0.17	−	0.19	0.098
	Mean ± SD	0.17	±	0.002	0.18	±	0.01	0.18	±	0.01
Cu	Range	4.39	−	6.45	7.30	−	9.81	9.69	−	11.87	25
	Mean ± SD	5.37	±	1.04	8.43	±	1.27	10.83	±	1.10
Cr	Range	3.02	−	3.44	4.20	−	4.60	3.26	−	3.68	85
	Mean ± SD	3.25	±	0.21	4.41	±	0.20	3.45	±	0.21
Pb	Range	6.21	−	7.40	6.67	−	7.03	6.30	−	7.13	20
	Mean ± SD	6.87	±	0.61	6.88	±	0.19	6.66	±	0.42
Zn	Range	28.82	−	31.34	35.14	−	37.02	35.54	−	37.21	71
	Mean ± SD	30.24	±	1.29	36.14	±	0.95	36.30	±	0.84
Co	Range	1.54	−	1.81	1.97	−	2.21	1.65	−	1.71	10
	Mean ± SD	1.67	±	0.14	2.12	±	0.13	1.68	±	0.03
Ni	Range	4.97	−	5.42	9.46	−	11.08	10.62	−	11.61	20
	Mean ± SD	5.16	±	0.23	10.34	±	0.82	11.16	±	0.50
V	Range	18.24	−	19.03	26.97	−	30.05	29.40	−	32.43	60
	Mean ± SD	18.75	±	0.44	28.13	±	1.68	31.03	±	1.53
Sb	Range	0.14	−	0.15	0.16	−	0.18	0.15	−	0.17	0.2
	Mean ± SD	0.15	±	0.01	0.17	±	0.01	0.16	±	0.01