Lead concentration in the drinking water Settings N Mean ± SD (mg / L) Min Max Over of VN standard (n /%) Ban Thi (1) 30 0, 0033 ±0, 0031 0, 002 0, 0135 3 (10, 0) Tan Long (2) 30 0, 0077 ±0, 0191 0, 0002 0, 0993 4 (13, 33) p1&2 (Mann Whitney test) 0, 581 15 Interpret: The means of lead concentration in drinking water in Ban Thi and Tan Long were not higher than the standard in Vietnam.