Table 2. Summary of trace element concentrations.

	United States	Namibia	Poland	Argentina	Total
Trace Element	(n = 20)	(n = 6)	(n = 23)	(n = 21)	(N = 70)
Calcium (mg/L)
M	268.72	143.83	227.06	231.79	233.25
SD	59.34	64.67	36.72	37.62	56.45
Min	138.02	36.69	152.94	177.47	36.69
Max	374.95	205.21	293.71	304.47	374.95
Iron (mg/L)
M	1.27	1.53	1	0.99	1.12
SD	0.26	0.86	0.15	0.21	0.35
Min	0.84	0.74	0.8	0.71	0.71
Max	1.85	2.97	1.38	1.51	1.38
Zinc (mg/L)
M	0.67	1.34	0.75	0.93	0.83
SD	0.43	1.29	0.46	0.5	0.59
Min	0.15	0.03	0.2	0.25	0.03
Max	1.61	3.75	2.02	2.01	3.75
Copper (μg/L)
M	169.52	130.94	186.87	211.04	184.4
SD	63.06	63.49	48.1	99.5	74.33
Min	71.48	55.6	82.95	89.52	55.6
Max	317.09	208.83	252.42	419.09	419.09
Manganese (μg/L)
M	2.71	11.6	1.61	7.62	4.58
SD	1.12	9.78	0.89	3.76	4.76
Min	1.46	2.79	0.22	3.29	0.22
Max	5.86	30.27	4.32	20.24	30.27
Arsenic (μg/L)
M	3.47	6.68	3.86	4.51	4.18
SD	0.84	2.46	1	1.34	1.5
Min	2.4	4.08	3.03	2.54	2.4
Max	6.02	11.2	7.9	9.08	11.2
Lead (μg/L)
M	0.77	2.15	1.02	0.59	0.91
SD	0.45	0.24	0.26	0.4	0.55
Min	0.41	1.92	0.52	0.21	0.21
Max	2.1	2.48	1.44	1.69	2.48