Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Commonly Consumed Shellfish from Kula, Rivers State, Nigeria

Abstract

Polycyclic Aromatic Hydrocarbons (PAHs) were assessed in shellfishes (whelk, oyster and periwinkle) from Kula, Rivers State, Nigeria. The PAHs determination was done using gas chromatography (GC) coupled with flame ionization detector (FID) (Hewlett Packard, Wilmington, DE, USA), powered with HP chemstation Rev. A09:01 (10206) software. Human health risk assessment models based on United States Environmental Protection Agency (USEPA) was used to characterize risks of PAHs exposure to non cancer (Hazard Index) while and excess cancer risk (ECR). From the results, Benzo [a] Anthrancene (BaA) had highest concentrations in whelk (0.689±0.003) and Periwinkle (0.930±0.001) while Naphthalene had highest concentration in oyster (2.000±0.000). The Total concentration of PAHs in µ g/kg for whelk, oyster and periwinkle were 1.797±0.013, 3.977 ±0.024 and 1.564±0.017 while the estimated daily intake (EDI) of PAHs (mg/kg/day) via consumption of shell fish ranged from 2.00x10-4 to 6.40x10-2, 7.0x10-4 to 1.86 x10-1 and 0 to 8.64x10-2 far above oral reference dose (RFD) respectively. The toxic equivalents (TEQs) values were 1.276x10-4, 1.252x10-4 and 4.034x10-4 for whelk, oyster and periwinkle respectively, were significantly (p<0.05) higher than the screening value (SV) for shellfish 1.81x10-5mg/kg. The estimated excess cancer risk (ECR) obtained for whelk was (3.0x10-4), oyster (2.00x10-4) and periwinkle (3.24x10-4). These values were far above the USEPA acceptable (1x10-4). From this study, it can be deduced that bioaccumulation of PAHs in the shellfish is a potential health hazard to consumers. Carcinogenic indices indicated that daily Intake of contaminated shellfishes exposures the local populace to cancer risks.