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. 2017 Aug 17;12(8):e0183367. doi: 10.1371/journal.pone.0183367

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