Table 5.
The average concentrations of toxic elements in Bualda, Fulbaria, Jamjami, and Komlapur’s groundwater from all tube wells that did not exceed the WHO health-based drinking water guideline for As.
| Element | Average concentration (μg/L) | WHO health-based guideline (μg/L) | Percent of unsafe tube wellsa |
|---|---|---|---|
| As | < 7 | 10 | 0 |
| B | < 50 | 500 | 0 |
| Ba | 110 | 700 | 0 |
| Cr | 2.4 | 50 | 0 |
| Fe | 400 | NAb | NA |
| Mn | 770 | 400 | 87 |
| Mo | 1.2 | 70 | 0 |
| Ni | 1.0 | 70 | 0 |
| Pb | < 0.2 | 10 | 0 |
| Sb | 1.2 | 20 | 0 |
| Sec | < 1 | 10 | 0 |
| U | 3.2 | 2 | 64 |
| Znc | 12 | NA | NA |
a
Ninety-three percent (42 of 45) of these tube wells are unsafe; that is, only 7% (3 of 45) of these tube wells do not exceed any of these WHO health-based drinking water guidelines.
b
Not applicable; the WHO has not established a health-based drinking water guideline for Fe or Zn (WHO 1996a, 1998a).
c
The severity of chronic As poisoning in Bangladesh might be magnified by a lack of Se or Zn or both (Frisbie et al. 2002; Ortega et al. 2003).