HEAVY METAL CONCENTRATIONS IN FROZEN HAKE FISH (Merluccius merluccius) FROM SELECTED COLD ROOMS IN BENIN CITY, EDO STATE

ABSTRACT

ThestudydeterminedtheconcentrationsofCadmium(Cd),Lead(Pb),Copper(Cu)andZinc(Zn) ( which are both essential and non-essential elements in the human body)in Merlucciusmerluccius from selected cold rooms in Benin City, Edo State, Nigeria with a view ofevaluatingthesustainabilityofthesefishforhumanconsumption.Fishsampleswerepurchased once a month from the different cold rooms between March 2020 to January 2021and analysed within 24hours. Samples were digested with 5ml of Perchloric acid (HCLO4)and 15ml of Nitric acid (HNO3) and analysed using Atomic Absorption Spectrophotometerwith the result presented in mg/kg. The mean concentration found in the fish was Cd 0.2636,Pb 3.381, Cu 3.035 and Zn 4.333. There were no significant difference (P>0.05) in the meanconcentration of Cd and Pb in the fish species between cold rooms, with exception of Cu andZn.TheEstimatedDailyIntake(EDI)values inmg/person/dayforheavymetals,rangedfromZn(0.178)asthehighesttoCd(0.011)asthelowest.TheToxicityQuotient(TQ)rangedfromPb(16.905)asthehighestto Cu(0.101)asthelowest.ThemeanconcentrationsofCuandZnfell below the limits established by the Food and Agricultural Organization of the UnitedNations (FAO), and CODEX Alimentarius for metals in food/fish except for Cd and Pb in thefish species. Thus, the consuming public should carefully monitor the level of metals theyconsume in this fish speciesin order to prevent the hazardous risk associated with theconsumptionofthisfrozenfish.ThisisbecausethehighlevelofCdandPbpresentinthefishcould bebecauseofthepreservationandstoragemethodsemployedinthecoldrooms.It wasproffered that in order to keep the levels of these metals within tolerable limits, HealthInspection Officers and Environmental Monitoring Officers, should be mandated to jointlymonitor the activities of fishmongers and to carry out periodic spot-checking of fisheryproducts