Evaluation of the Potential Hazard of Consuming Allium Cepa (Onion) Cultivated On Farmlands Along Hunkuyi-Zaria Road Kaduna State Nigeria

Heavy metal contamination of Allium cepa (onion) cultivated along Hunkuyi-Zaria Kaduna State, Nigeria was determined using standard procedure for the analysis of these metals by Atomic Absorption Spectrometry (AAS), Shimadzu 6800. Metal concentration were determined in dry and wet season. The average values for copper, lead, cadmium zinc and chromium during dry season were 1.5, 66.3, 0.7, 89.8 and 12.2 mg/kg respectively. For wet season, the values were 1.7, 120.3, 0.7, 81.9 and 13.4 mg/kg for copper, lead, cadmium, zinc and chromium respectively. With the exception copper and zinc which have 73.3 and 99.4 mg/kg as their World Health (WHO) permissible limit, these average values were higher than WHO of 0.3, 0.2 and 2.3 mg/kg for lead, cadmium and chromium respectively in vegetable. Target Hazard Quotient (THQ) for each element across the two seasons was above 1.00 except for copper in dry season and chromium in both seasons.