Abstract

DETERMINATION OF SELECTED HEAVY METALS (HM) IN COCOYAM AND CASSAVA FLOUR SOLD IN EKE AWKA MARKET: A HEALTH RISK ASSESSMENT

*Asomugha Roseline Ngozi PhD, Ogbonnaya Mba, MSc, Orji Ernest Chima PhD, Okoro P. Kamsy, Nwachuku A. and Petercletus D.

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Abstract

There is a tendency for food samples to be contaminated with heavy metals either from the soil where they are cultivated or during the processing. This study assessed the concentrations of the chosen heavy metals in the test and control cocoyam and cassava flour samples: arsenic, cadmium, lead, mercury, zinc, copper, and aluminum. The heavy metal contents of the control and test samples was assessed using the Thermo Elemental Atomic Absorption Spectometer. Probabilistic risk assessment techniques was used to estimate daily heavy metal intake, and calculate the Hazard Quotient, Hazard Index, and Incremental Life Cancer Risk linked with heavy metal exposure. While lead and arsenic for both samples were above the reference level for both adults and children, the estimated daily consumption for cadmium, copper, zinc, and aluminum for both the control and test samples of cocoyam flour was below the acceptable reference values. While copper, zinc, and aluminum were under the oral standard range for both adults and children, the estimated daily consumption of cadmium, arsenic, and lead for the cassava test sample was likewise higher than the reference level for children. In adults and children, the test and control samples of cocoyam and cassava flour had hazard quotients for copper, zinc, and aluminum that were all less than one, indicating no possible health hazards. Arsenic, lead, and cadmium had hazard quotients of more than one in the cassava test sample, which could be harmful to human health when consumed in cocoyam and cassava flour. A hazard index score greater than one showed the cumulative non-carcinogenic threat of the metals under investigation. The US Environmental Protection Agency's 10-4 priority risk threshold and the 10-6 acceptable risk limit were both exceeded by the cumulative cancer risk for the cocoyam and cassava test and control samples. This study has illustrated the possible health hazards that prolonged consumption of cocoyam and cassava flour contaminated with heavy metals could pose to the general public.

Keywords: Estimated daily intake, Hazard quotient, Hazard index, Incremental life cancer risk, Heavy metals.