Petroleum Hydrocarbons and Heavy Metals Risk of Consuming Fish Species from Oguta Lake, Imo State, Nigeria

Abstract

Oguta lake has experienced lots of oil spills and heavy metals and petroleum hydrocarbons could constitute fish contaminants. In order to assess the potential danger associated with consumption of fish from the lake by children and adults the current research was conducted. 6 g of each fish species from the lake were homogenized and divided into two portions. One was digested with aqua-regia while the other was extracted with hexane using a soxhlet extractor. Extracts were analyzed for heavy metal and hydrocarbons concentrations with AAnalyst Perkin Elmer 400 AAS and Buck 530 GC respectively. Data was interpreted with pollution and risk assessment models. Results revealed that except for Hg and Ni all other metals were below permissible levels by Food and Agricultural Organization (FAO). Estimated dietary intakes (EDI mg/kg day^-1) were high in children (110.157) for C. spectaculurus to (25.212) for H. fossilis while adult (18.885) C. spectaculurus to (7.951) for H. fossilis. EDI varied for children (Fe > Hg > Zn > Ag > Pb > Ni > Cu > Cd) and (Fe > Zn > Hg > Ag > Pb > Ni > Cu > Cd) for adults. Target Hazard Quotient (THQ) was highest for Cd in both adults and children. Total petroleum hydrocarbon (µg/l) was high in O. leucosticus (11113755.94) > H. fossilis (40210.66) > C. spectaculums (35184.44) > M. salmoides (6373.27). Fish species from Oguta lake could constitute a health risk with significant potential carcinogenic risk both in children and adults as estimated from fish consumption.