Health risk assessment of heavy metals from pesticides use in Plateau State, Nigeria

Abstract

Heavy metals bioaccumulation in agricultural crops fumigated with pesticides has growninto a major concern globally. This study assessed heavy metals concentrations (Cd, Pb, Cr, Cu, Zn) in commonly consumed crops and their corresponding soil from agricultural farm lands in Jos Plateau State, Nigeria. The mean concentrations of heavy metals in the studied crops ranged from 0.17-100.75, 0.17-54.33, 0.83-28.75, 0.17-5.50, 0.5-0.5mg/kg for Zn, Pb, Cu, Cr, and Cd respectively. The trend of heavy metals in the crops were in decreasing order of Zn>Pb>Cu>Cr>Cd and their concentrations varied in different parts of the crops. The mean concentration of Cd, Pb, and Cr in the studiedcrops were above the WHO, (2019) permissible limits and therefore a call for concern. The mean concentrations of heavy metals in the soil varied from 0.5-0.5, 2.50-13.83, 3.67-5.75, 11.83-26.33, and 41-89.50 mg/kg for Cd, Pb, Cr, Cu and Zn respectively and were below the UNEP, (2013) permissible limits for agricultural soil. The result showed that Pb had the highest transfer factor (1.91) in (Capsicum annuum) and Zn had theleast. Similarly, the result revealed high Pollution index value for Pb compared to other metals. Hazard quotient and Hazard index of all the crops were less than 1; thus the consumption of these crops is unlikely to pose health risks to the target population. However, the result showed health risk from daily intake of some of the studied crops for Pb ((Brassica oleracea, Lactucasativus, Zea mays, Spinaciaoleracea, and Capsicum annuum). Hence, regular monitoring and screening of pesticides for heavy metals should be employed by government agencies.