Background. Fish advisories have been established by some nations to protect the public from
the potentially harmful health effects linked to eating contaminated fish. Advisories are based on
estimations of the health risks associated with concentrations of contaminating chemicals found in
fish, and the average levels of consumption of fish in the population. Fish is an important source of
nutrition in Ghana; however, little is known about the possible health effects associated with metal
concentrations found in fish.
Objective. The overall aim of the present study was to estimate metal concentrations in
fishery resources so as to inform guidelines on fish consumption.
Methods. We collated previously published data on levels of metals in fish in Ghana. We also
estimated the potential for adverse health effects by calculating a hazard quotient (HQ) based
on the reported levels of mercury in fish and either the United States Environmental Protection
Agency (USEPA) Reference Dose (RfD) or the FAO/WHO Expert Committee on Food Additives
Provisional Tolerable Weekly Intake (PTWI). Both are estimates of methylmercury exposure
that is considered safe (0.0001 mg/kg body weight (bw) per day and 0.0016 mg/kg bw/week,
respectively). We also compared HQ estimates across different fish species and water bodies in
Ghana.
Results. Mercury was the only metal for which there was sufficient data to estimate the possible
adverse health effects from eating fish caught in Ghana. The mean concentration of mercury was
0.10 mg/kg (± 0.15) wet weight (N= 63 fish samples). This concentration was associated with a
HQ of less than 1 when using the Joint FAO/WHO PTWI, but above 1 when using the USEPA
RfD. Higher concentrations of mercury (Hg) were detected in fish collected from rivers in gold
mining areas of Ghana (0.25 mg/kg ww ±0.23) versus fish collected from lakes/reservoirs (0.04
mg/kg w.w ±0.04) and marine areas (0.06 mg/kg w.w ±0.04).
Conclusions. These results suggest regular monitoring of fish collected from water bodies in
gold mining regions is warranted. Results also suggest that regulatory bodies may want to
consider the development of guidelines for fish consumption advisories when warranted,
and remediation of primary sources of mercury contamination to optimize the health
benefits of fish consumption.
Competing Interests. The authors declare no competing financial interests.