Polycyclic aromatic hydrocarbons (PAHs) levels in two commercially important fish species from the coastal waters of Ghana and their carcinogenic health risks

Abstract

Polycyclic aromatic hydrocarbons (PAHs) concentrations were measured by gas chromatography with flame ionization detector (GC/FID) in two fish species, Sardinella maderensis (Flat sardinella) and Galeoides decadactylus (Lesser African threadfin or Shine-nose or Common threadfin) from Ghanaian coastal waters and the carcinogenic health risks, associated with the consumption of these fishes, estimated. The average concentrations of PAHs ranged from below detection limit of 0.01 μg/kg wet wt to 34.04 ± 0.56 μg/kg wet wt in S. maderensis, and from below detection limit (0.01 μg/kg wet wt) to 54.13 ± 5.22 μg/kg wet wt in G. decadactylus. Pyrene had the highest mean concentration of 54.13 ± 5.22 μg/kg wet wt in G. decadactylus from Tema. Both fish species from Tema and Chorkor showed similar PAH assemblages although the concentrations were different, suggesting common source of PAHs in these coastal environments. G. decadactylus accumulated significantly higher (P < 0.05) concentrations of total PAHs at all the sites, except at Chorkor. High molecular weight PAHs (HMW-PAHs) were generally predominant compared to low molecular weight PAHs (LMW-PAHs). The LMWPAH/ HMW-PAH ratios were < 1 for both species, indicating anthropogenic, mainly pyrogenic, origin of PAHs in the Ghanaian coastal environment. With the exception of G. decadactylus from Ada-Foah, benzo(a)pyrene concentrations in the fish samples analysed exceeded the EU recommended limit of 2 μg/kg wet wt for fish considered safe for human consumption. The estimated carcinogenic potency equivalent concentrations exceeded the screening value for both species from all the study areas, indicating significant carcinogenic health risks associated with the consumption of these fishes. A further study of PAHs and other contaminants in seafood, landed on the coast of Ghana, is recommended in the light of recent discovery and drilling of oil in commercial quantities in Ghanaian coastal waters.