Health risk assessment and heavy metal contamination levels in vegetables from Tamale Metropolis, Ghana

Background One major route of heavy metal exposure/ accumulation to humans is via vegetable consumption. The study assessed the levels of heavy metals and their associated health risk in frequently consumed vegetables in the Tamale Metropolis. Results Cadmium concentration in cabbage, carrot, green pepper, onion and tomato ranged from 0.04 to 0.07 mg kg− 1, 0.01 to 0.06 mg kg− 1, 0.04 to 0.06 mg kg− 1, 0.03 to 0.06 mg kg− 1 and 0.03 to 0.07 mg kg− 1, respectively. Lead concentration in cabbage, carrot, green pepper and onion ranged from BDL to 0.03 mg kg− 1, BDL to 0.02 mg kg− 1, BDL to 0.04 mg kg− 1, and BDL to 0.05 mg kg− 1, respectively. The concentration of heavy metals in the various vegetables were below the World Health Organisation (WHO) standard. Conclusions The individual hazard index of vegetables for both children and adults were below 1, indicating no potential risk to the public except for cadmium, chromium and manganese. The study also revealed that the hazard index of heavy metals studied were above 1, indicating non-acceptable level of non-carcinogenic adverse health effect.