Bioaccumulation and Consumption Safety of a Sea Food, Gastropod Mollusc (Thais coronata): Polycyclic Aromatic Hydrocarbon (PAH) Perspective

Abstract

Seafood and other environmental matrices are major entry route of harmful pollutants into humans due to constant contamination of the aquatic environment hence requires monitoring. This study scientifically explored the hypothesis that benthic gastropods bioaccumulate harmful pollutants that pose health risk to consumers of the sea food. Fifty samples of Thais coronata were collected per site from major regional fish landings. Two hundred samples were collected monthly for eight months to determine the concentrations of polycyclic aromatic hydrocarbon-PAH and possible health risks due to consumption using regulatory limits for guidance. Total PAH concentrations (μg/kg) varied between 65.68–173.52 suggesting differences in consumed concentrations at different times. The concentration of individual PAH congeners (1.376 ± 0.07-40.356±2.21 μg/kg) and PAH4 were below the European Union maximum limits. The Daily Dietary Intake values ranged from 0.075-2.212 μg/kg for individual PAH congeners while that of PAH4 was 1.359 μg/kg and were all below their respective reference oral doses. The carcinogenic potencies of the PAH congeners ranged from 0.001-143.389, the carcinogenic toxic equivalents (TEQs) of all PAH congeners was 0.1522 while that of PAH4 was 0.0044. The Excess cancer risk (ECR) value (10^-8–10^-5) was within USEPA guideline of 10^-6 while the margin of exposure (MOE) of individual PAHs and PAH4 were higher than critical border line of 10,000 given by European Food Safety Authority but diagnostic ratio suggested PAH sources of pyrogenic origin in samples monitored. The study concluded low health risk for consumers of the shellfish (Thais coronata) in the study region but with recommendation advisory for regular monitoring to observe changes.