Table 3.
The average concentrations of toxic elements in Bualda, Fulbaria, Jamjami, and Komlapur’s groundwater from all tube wells that 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 | 84 | 10 | 100 |
| B | < 50 | 500 | 0 |
| Ba | 220 | 700 | 0 |
| Cr | 9.5 | 50 | 5 |
| Fe | 7,300 | NAb | NA |
| Mn | 870 | 400 | 59 |
| Mo | 2.0 | 70 | 0 |
| Ni | 31 | 70 | 5 |
| Pb | 1.2 | 10 | 5 |
| Sb | 2.3 | 20 | 0 |
| Sec | < 1 | 10 | 0 |
| U | 0.9 | 2 | 14 |
| Znc | 21 | NA | NA |
a
By definition, 100% (22 of 22) of these tube wells are unsafe because they all exceed the 10 μg/L WHO health-based drinking water guideline for As.
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).