Lead concentration in the soil Settings N Mean ± SD (mg / kg) Min Max Over of VN standard * (n /%) Ban Thi (1) 30 2980, 23 ± 6092, 84 80, 05 33820, 62 30 (100, 0) Tan Long (2) 30 263, 46 ± 367, 84 11, 72 1790, 36 22 (73, 33) p1&2 (Mann Whitney test) < 0, 001 * Vietnamese standard Interpret: The lead concentration in the soil was 10 times more likely in Ban Thi than in Tan Long, and it was 43-time higher than the standard in Vietnam Table 3.17.