Assessment of health risks from consumption of food crops fumigated with metal based pesticides in Gwadam, Gombe State, Nigeria

Abstract

Intensive use of agrochemicals has led to build of heavy metals in the soil ecosystem and their transfer to edible parts of crops. This study was aimed to determine the heavy metals (Cd, Pb, Cr, Cu and Zn) concentrations in some twenty commonly used pesticides in northern Nigeria, and health risk associated from the consumption of food crops fumigated with these pesticides as the only source of metal contamination. Heavy metals content in pesticides, food crops and soils were analyzed after acid digestion using atomic absorption spectrometry. Traces of heavy metals (Cd, Pb, Cr, Cu and Zn) were detected in most of the pesticides. The concentrations of heavy metals in crops fumigated with pesticides ranged from 0.33-4.68, 1.75-38.08, 0.67-16.83, 9.01-436.75, 0.17-20.80mg/kg for Cd, Pb, Cr, Cu, and Zn respectively. The mean concentrations of Cd, Pb, and Cr in all the crops were above WHO, (2019) permissible limit. Heavy metals in soils of corresponding crops were below the permissible limits by UNEP, (2013) and NESREA, (2011). Bioaccumulation factor BAF showed high BAF>1 for Cu and Pb in all the studied crops,while pollution index value revealed contamination for Cd and Pb in all the studied crops. Hazard quotient showed potential health risk from the consumption of only Capsicumannuum for Pb. However, consumers may experience advance health risk through the consumption of Oryza sativa, Zea mays, Solanumlycopersicum, Capsicumfrustescens for all metals (Hazard index). Hence, there is the need for screening of heavy metals in pesticides and monitoring of metals contents in food crops.