Polycyclic Aromatic Hydrocarbons in Two Commonly Consumed Fresh and Smoked Fishes in Ekiti State and their Effects on Human Health

Background and Objective: Polycyclic aromatic hydrocarbons have received substantial consideration as an environmental organic pollutant in many continents such as Africa, Europe, and Asia as well as parts of America. Many polycyclic aromatic hydrocarbon compounds have been proven, identified and quantified in nearly all segments of the environment due to their carcinogenicity, mutagenicity, and cytotoxicity even at very low concentrations. The objective of the study was to look at the levels of polycyclic aromatic hydrocarbons in fresh and smoked Scomber scombrus (Atlantic mackerel or Titus) and Trachurus trachurus (horse mackerel or kote in southwestern Nigeria) sold in Ado-Ekiti major markets, Nigeria and also assess the risks involved in their exposure and consumption.

Materials and Methods: Fresh and smoked samples of two selected fishes (Kote and Titus) were taken for this study. They were cleaned and wrapped in aluminium foils, then refrigerated and the homogenized samples were extracted simultaneously by solvent-solid and Soxhlet extraction. The extracts were analyzed for sixteen polycyclic aromatic hydrocarbons using the Agilent 6890N GC-FID/MS. One and 2-way ANOVA and SPSS were employed for the statistical analysis.
Results: The mean total polycyclic aromatic hydrocarbons levels in the fish samples ranged from 0.028 and 0.145 μg/kg. 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 samples, indicating anthropogenic, mainly pyrogenic, the origin of PAHs in the sourced environment. Risk assessment conducted using benzo(a)pyrene carcinogenic and mutagenic toxicity equivalency factors (TEF and MEF, respectively) showed low risk (8.69e-08 – 5.93e-07 and 1.02e-07 – 1.83e-07 μg/kg, respectively for carcinogenicity and mutagenicity) associated with consuming both smoked and fresh fish samples were below USEPA guideline (1.0e-05) for potential cancer risk. The mean hazard indexes ranged from 6.77e-08 – 4.61e-07 and were below 1 in line with an acceptable cumulative threshold. Correlation is significant at the 0.01 < P > 0.05 levels (2-tailed).

Conclusion: This study showed that there are no adverse health effects of PAHs content on consumers of these two fish samples, however, levels of PAHs present in smoked fish may pose elevated cancer risks if consumed at high consumption rates over a long period.