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,Papa Toah Akonor,Sylvester Yao Lokpo,Nathaniel Owusu Boadi,Matilda Ayim-Akonor,Clement Tettey

doi:10.1016/j.toxrep.2020.02.011

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.

Highlights

IntroductionThe water resources promote development in socio-economic issues crucial to society in general and for industries, agricultural activities, and domestic use
Water is one of the most vital elements of the ecosystem
Toxic metals concentrations in the rivers decreased in the order of Hg > Pb > Cd > As

Summary

Introduction

The water resources promote development in socio-economic issues crucial to society in general and for industries, agricultural activities, and domestic use. In this 21 st century, the provision of clean drinking (potable) water for the growing population of the world is one of the most challenging issues humans have had to encounter [1]. There have some occurrences of local metal pollutions through natural weathering, in most cases, anthropogenic activities have caused metals to become an environmental health issue [3]. It is well acknowledged that natural processes likewise discharge or leachates from several anthropogenic activities are known causes of the incidence of heavy metals (HM) in aquatic environments [4]

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