Table 3.
Total mercury (Hg) concentrations (µg/g d.w.) in urine (µg/L), hair, soil, sediment, and fish samples collected 2010–2012 in Gorogo, Kejetia, and Bolgatanga, Upper East Region.
| Study Location | Media | Year Collected | n | Mean (SD) | Median | Min.-Max. | Exceeds Guideline (%) | Guideline Value |
|---|---|---|---|---|---|---|---|---|
| Kejetia women of childbearing age | Urine | 2010 | 84 | 7.82 (38.2) | 1.38 | 0.096–336.7 | 5 (6.0) | 10 µg/L a |
| Kejetia women of childbearing age | Hair | 2010 | 80 | 1.66 (10.3) | 0.359 | 0.097–92.6 | 1 (1.3) | 11.1 µg/g b |
| Gorogo households | Soil | 2011 | 26 | 0.041 (0.023) | 0.039 | 0.013–0.114 | 0 (0%) | 6.6 µg/g c |
| Kejetia households | Soil | 2010 | 17 | 4.78 (9.78) | 2.16 | 0.096–40.969 | 3 (17.6) | |
| Kejetia households | Soil | 2011 | 54 | 15.6 (46.9) | 3.05 | 0.297–330.04 | 18 (33.3) | |
| Bolgatanga gold refinery | Soil | 2012 | 4 | 57.8 (58.2) | 54.6 | 5.43–116.44 | 3 (75.0) | |
| Kejetia and surrounding areas | Sediment | 2010 | 14 | 0.036 (0.062) | 0.021 | 0.005–0.248 | 1 (7.1) | 0.170 µg/g d |
| Kejetia and surrounding areas | Fish (unknown fresh water species) | 2010 | 12 | 0.070 (0.057) | 0.045 | 0.024–0.220 | 0 (0%) | 0.3 µg/g e |
a Expected to be asymptomatic <10 µg/L [40]; b U.S. EPA [15] benchmark dose of 11.1 µg/g; UNEP guideline of 10 µg/g [41]; c Canadian Soil Quality Guideline for inorganic Hg at residential sites [42]; d Canadian Sediment Quality Guideline for Hg in freshwater sediment [43]; e U.S. EPA Tissue Residue Criterion for MeHg in fish [44].