HEAVY METAL CONCENTRATIONS IN THE ATLANTIC HORSE MACKEREL (Trachurus trachurus) FROM SELECTED COLD ROOMS IN ONITSHA, ANAMBRA STATE, NIGERIA

ABSTRACT

The study was undertaken to assess the human health risk of some heavy metals namely Lead (Pb), Cadmium (Cd), Zinc (Zn) and Copper (Cu) in frozen Trachurus trachurus from selected cold rooms in Onitsha, Anambra State, there is a lack of information regarding the heavy metal content in this fish species in this location. Fish sample were purchased from selected cold rooms monthly between July 2020 and December 2020 and taken to the laboratory for analysis within 24 hours. Samples were digested in 10ml Nitirc acid and 10ml Sulphuric acid at the ratio 1:1. Specifically, the levels of Pb, Cd, Zn and Cu were quantified by Atomic Absorption Spectrophotometer techniques in order to ascertain their suitability for human consumption. The mean concentration of heavy metal in frozen T. trachurus ranged from 0.0289 mg/kg for Cd to 7.077 mg/kg for Zn. The Hazard Quotient (HQ) for all the heavy metals were Below Quantification Limit (BQL) in frozen T. trachurus while the Estimated Daily Intake (EDI) values in mg/person/day for heavy metals ranged from 0.001156 for Cd to 0.28308 for Zn in frozen T. trachurus . The mean concentrations of heavy metals analyzed in T. trachurus had a profile of Zn > Cu > Pb > Cd and were below the limits recommended by FAO/CODEX Alimentarius and Commission Regulation for metals in food fish. Thus, the consuming public is not at risk of the hazards associated with these metals via consumption. The heavy metal concentrations in frozen T. trachurus should be monitored to ensure that safety limits are not exceeded. Relevant government agencies should educate the public on the dangers of excess levels of heavy metals in fish so as to reduce possible heavy metal poisoning also further studies on other heavy metals not covered within the scope of this work should be carried out.