Table 3.
The concentrations of heavy metals in drinking water in different villages and different water source.
| Category | n | Concentration (Mean (Range)) | ||||
|---|---|---|---|---|---|---|
| Pb (ug·L−1) | Cd (ug·L−1) | Zn (mg·L−1) | As (ug·L−1) | Hg (ug·L−1) | ||
| Water source | ||||||
| Open wells | 2 | 0.06 (BDL–0.18) | 0.029 (BDL–0.054) | 0.115 (0.018–0.306) | 0.568 (0.034–1.247) | 0.081 (0.048–0.13) |
| Hand-pressed wells | ||||||
| Depth < 3m | 4 | 3.51 (BDL–10.53 *) | 0.227 (BDL–0.53) | 0.026 (0.004–0.056) | 3.209 (0.262–4.683) | 0.070 (0.060–0.076) |
| Depth = 3~6 m | 4 | BDL | 0.02 (BDL–0.076) | 0.027 (0.022–0.039) | 1.824 (BDL–5.802) | 0.074 (0.030–0.106) |
| Depth > 6 m | 4 | BDL | 0.126 (BDL–0.35) | 0.0195 (0.006–0.033) | 2.582 (0.059–6.428) | 0.047 (BDL–0.106) |
| Spring water | 1 | BDL | BDL | 0.027 | 0.000 | 0.051 |
| Tap water | 1 | BDL | BDL | 0.025 | BDL | BDL |
| Barreled water | 1 | BDL | BDL | 0.030 | BDL | BDL |
| Villages | ||||||
| MaTian | 9 | 0.824(BDL~10.53 *) | 0.098(BDL–0.53) | 0.045 (0.004–0.306) | 2.227 (0.034–6.428) ** | 0.069 (BDL–0.13) |
| ZhuDui | 6 | BDL | 0.0860(BDL–0.18) | 0.026 (0.02–0.03) | 0.316 (BDL–0.947) | 0.0520 |
| Chinese drinking water standard (GB5749-2006) | 10 (ug·L−1) | 5 (ug·L−1) | 1(mg·L−1) | 50 (ug·L−1) | 1 (ug·L−1) | |
BDL represents below detection limit, The detection limits were 0.01, 0.008, 0.008, 0.008 and 8 μg·L−1 for Pb, Cd, As, Hg, and Zn, respectively. * Exceeded the Chinese drinking water standards. ** The concentration of Arsenic (As) in MaTian is significantly higher than in ZhuDui. The concentrations of the five heavy metals in different water sources in differents depth were not statistically significantly different.