Health risk assessment and levels of toxic metals in fishes (Oreochromis noliticus and Clarias anguillaris) from Ankobrah and Pra basins: Impact of illegal mining activities on food safety

Nii Korley Kortei; Marcus Ekow Heymann; Edward Ken Essuman; Fidelis Mawunyo Kpodo; Papa Toah Akonor; Sylvester Yao Lokpo; Nathaniel Owusu Boadi; Matilda Ayim-Akonor; Clement Tettey

doi:10.1016/j.toxrep.2020.02.011

Health risk assessment and levels of toxic metals in fishes (Oreochromis noliticus and Clarias anguillaris) from Ankobrah and Pra basins: Impact of illegal mining activities on food safety

Toxicol Rep. 2020 Feb 17:7:360-369. doi: 10.1016/j.toxrep.2020.02.011. eCollection 2020.

Authors

Nii Korley Kortei¹, Marcus Ekow Heymann¹, Edward Ken Essuman¹, Fidelis Mawunyo Kpodo¹, Papa Toah Akonor^{2

3}, Sylvester Yao Lokpo⁴, Nathaniel Owusu Boadi⁵, Matilda Ayim-Akonor⁶, Clement Tettey⁷

Affiliations

¹ Department of Nutrition and Dietetics, School of Allied Health Sciences, University of Health and Allied Sciences, PMB 31, Ho, Ghana.
² Department of Food Processing and Engineering, CSIR- Food Research Institute, P.O. Box M20, Accra, Ghana.
³ Department of Nutrition and Food Science, School of Biological Sciences, College of Basic and Applied Sciences, University of Ghana, P.O. Box LG 25, Accra, Ghana.
⁴ Department of Medical Laboratory Sciences, School of Allied Health Sciences, University of Health and Allied Sciences, PMB 31, Ho, Ghana.
⁵ Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
⁶ Animal Health and Food Safety Division, CSIR- Animal Research Institute, P.O. Box AH20, Achimota, Ghana.
⁷ Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, PMB 31, Ho, Ghana.

Abstract

Arsenic (As), mercury (Hg), Cadmium (Cd) and lead (Pb) are toxic heavy metals that naturally occur in the ecosystem. Their levels are on the rise due to anthropogenic activities posing threat to aquatic wildlife and humans. In Ghana, pollution of some water bodies has led to unsafe consumption of riverine fishes as well as a shortage of treated potable water principally because the cost of treating polluted water has become expensive across the country. This study aimed to assess the As, Hg, Pb and Cd concentrations in water and fishes from rivers Pra and Ankobrah where activities of artisanal gold mining were carried out resulting in gross pollution of the water bodies. An experimental study was performed to ascertain the levels of As, Hg, Pb and Cd in fish species of Nile tilapia (Oreochromis noliticus) and mudfish (Clarias anguillaris) and aquatic media (water) from the Pra and River Ankobrah basins using the Atomic Absorption Spectrophotometer (AAS) (Varian AA240FS). Both river water samples recorded ranges of 0- 0.0040, 0.0060- 0.0387, 0 - 0.0020, 0.006-0.0093 mg/l for Cadmium, Lead, Arsenic and Mercury respectively. For Cadmium and Arsenic, their levels were comparable (p > 0.05). However, detected values for Lead and Mercury were no comparable (p < 0.05). Toxic metals concentrations in the rivers decreased in the order of Hg > Pb > Cd > As. For the fish samples, values ranged 0-0.08, 0.04-0.42, 0-0.04, and 0.40- 0.60 mg/kg for Cadmium, Lead, Arsenic and Mercury respectively. Generally, appreciably high values were obtained for Mercury. Toxic metals concentrations in the rivers decreased in the order of Hg > Pb > Cd > As. Human health risk assessment from heavy metal exposure through fish consumption from the Rivers for both children and adults showed no significant non-carcinogenic adverse health risk to humans since all calculated values for Hazard Quotient (HQ) were <1. Nonetheless, Target Hazard Quotient (THQ) values calculated for children and adult exposure to Cadmium and Mercury were>1 which implied a likely cause of adverse effects during a person's lifetime.

Keywords: Clarias anguillaris; Illegal mining activity; Mudfish; Oreochromis noliticus; Tilapia; Toxic metals; “Galamsey”.