Assessment of chromium, nickel, cobalt and zinc in edible flesh of two tilapia fish species found in Bodo River, Rivers State, Nigeria

Abstract

Oil exploration, exploitation, oil well fires and pipe-line vandalism are often reported to lead to high levels of pollution of the environment affecting water, land and air. As a result, the safety of specific fish species for human consumption is constantly in doubt and needs assessment. Guinean tilapia ( Tilapia guineensis ) and Blackchin tilapia ( Sarotherondon melanotheron ) are two of the highly consumed fish species in Bodo River. The level of chromium, nickel, cobalt and zinc in the flesh of Tilapia guineensis and Sarotherondon melanotheron found in Bodo River were studied using X-ray fluorescence (XRF). The amount of chromium found in the two fish species ranged between 10.3-10.5mg/kg, nickel 8.7-10.2mg/kg, cobalt 3.0-4mg/kg and zinc 71.2-74.5mg/kg. The levels of Cr, Ni, Co and Zn found in these two species of fish were compared to WHO maximum permissible levels of fish for consumption. The results showed that, fish from the study area contain amount of these metals investigated. This result will serve as a baseline for Food Agencies in Nigeria to certify safety of fishes from various rivers before they are sold for consumption to the public is hereby highlighted. Keywords: X-ray fluorescence, Chromium, nickel, cobalt, zinc, Guinean tilapia ( Tilapia guineensis ), Blackchin tilapia ( Sarotherodon melanotheron ), Bodo River