Hazard Analysis of Trace Metals in Muscle of Sarotherodon Melanotheron and Chrysichthys Nigrodigitatus from Okulu River, Rivers State, Nigeria

Abstract

Introduction: An instance of fish deaths in marine waters surrounding some communities in Bonny and Andoni Local Government Areas in Rivers State was reported in March-April 2020. This study investigated trace metals hazard in muscle of Tilapia (Sarotherodon melanotheron) and Silver Catfish (Chrysichthys nigrodigitatus) from Okulu River, Rivers State, Nigeria.
 Materials and Methods: Tissues of 24 samples of Sarotherodon melanotheron and Chrysichthys nigrodigitatus obtained from the river were analyzed using atomic adsorption spectrophotometer, and the health risk was estimated based on estimated daily intake (EDI), target hazard quotient (THQ), and total target hazard quotient (TTHQ).
 Results: The concentration (mg/kg) of iron, zinc, manganese, copper, cadmium, lead, and chromium in both species ranged 4.00 – 197.30, 9.20 – 35.30, 0.20 – 5.00, 0.00 – 73.10, 0.00 – 1.30, 0.00 – 54.70, and 0.00 – 0.50, respectively. The EDI of trace metals resulting from the consumption of both fish species was higher than the permissible tolerance intake (PTI) mg/day/60kg body weight. The THQ and TTHQ were < 1, indicating that the consumption of this food fish portends no known health concern. However, the carcinogenic risks exceeded the threshold level of 10-6 - 10-4, thus, reflecting carcinogenic tendency. Based on the results obtained, it must be ensured that the effluents discharged into open water bodies meet the recommended limits.
 Conclusion: There is a need to create awareness among consumers of food fish in the study area. There should be periodic monitoring of trace metals in surface waters and its food fish population to forestall potential health impact on humans.