HEALTH RISK EVALUATION OF CHILDREN AND ADULTS VIA THE CONSUMPTION OF FRESH AND SALT WATER FISH AND SHELLFISH CONTAMINATED WITH HEAVY METALS FROM THE NUN RIVER, BAYELSA STATE, NIGERIA

*Markmanuel D. P., Markbere O. B. and Abasi C. Y.

ABSTRACT

This study investigated the levels of As, Pb, Cd, Cr and Ni in fresh and salt water fish and shellfish species and evaluated the health risk of children and adults via the consumption of these species from the Nun River. The mean metal levels were determined by AAS. Cr levels were above the threshold limits of FAO/WHO and IEAE, while Pb, As, Cd and Ni were within or below their threshold values in both fresh and salt water species. The health risk evaluation results revealed that children are at greater risk of exposure to these contaminants compared to adults in all the species. The CDI (mg/kg-bw/day) values for both children and adults were either below or within the provisional tolerable daily intake (PTDI) set by regulatory bodies. The non-carcinogenic risk results were all < 1, indicating that the exposed populations are unlikely to experience non-carcinogenic health hazard at the moment. The carcinogen risk evaluation revealed that Pb, Cd and Cr will posed a risk of 3-5 persons in a thousand rather than threshold value of 1.00E-04 for both children and adults. Ni values were within the limits of 1.00E-06 but lower than 1.00E-04 while, TRc values of As were all below the threshold values of 1.00E-06 – 1.00E-04 set by USEPA. Therefore, in view of the potential risk pose by these contaminants to children and adults from this study, there is need for continuous monitoring of contaminants in the Nun River, Bayelsa State.

Keywords: Fish and Shellfish, Heavy Metal, Nun River, Carcinogenic and Non-carcinogenic Risk.