Heavy metals concentration in food crops irrigated with pesticides and their associated human health risks in Paki, Kaduna State, Nigeria

Abstract

The widespread use of pesticides containing heavy metals on agricultural farms has evolved into a significant source of metal pollution in food crops. In Paki, Nigeria, this study investigated the probable health dangers linked with consuming heavy metals contaminated crops fumigated with pesticides containing metals and grown exclusively from borehole water sources. An atomic absorption spectrometry test was used to determine the amounts of heavy metals (Cd, Pb, Cr, Cu, and Zn) in the (root, stem, leaf, and fruit) of certain selected food crops and soil. Potential non-cancer health risks (hazard quotient and hazard index) and target cancer risk (TCR) were computed based on USEPA 2019 guidelines. Heavy metals were found in all of the tested food crops and ranged from 1.00 ± 0.04 to 9.50 ± 0.35, 0.50 ± 0.29 to 5.33 ± 0.16, 0.25 ± 0.12 to 1.50 ± 0.03, 3.17 ± 0.17 to 31.8 ± 0.44, 14.08 ± 0.88 to 44.00 ± 0.29 mg/kg for Cd, Pb, Cr, Cu, and Zn, respectively. The levels of cadmium and lead in all of the studied food crops analyzed were higher than the acceptable limit. Heavy metals in the soil of the investigated crops ranged from 0.33 ± 0.00 to 1.17 ± 0.17, 0.83 ± 0.33 to 3.08 ± 0.05, 0.50 ± 0.02 to 1.1 ± 0.17,4.83 ± 0.20 to 31.50 ± 0.29, 5.00 ± 0.09 to 61.3 ± 0.29 mg/kg for Cd, Pb, Cr, Cu, and Zn, respectively. Heavy metal concentrations in the corresponding soil of all pesticide fumigated crops were significantly higher than in control soil. The Hazard quotient showed that children will experience potential non-cancer risks through the consumption of Allium cepa, Daucus carota, and Solanum lycopersicum for cadmium. The combined multiple effects of the studied metals (HI) indicated that children will experience severe non-cancer health risks through the intake of most of the studied crops. The target cancer risk (TCR) of Cr and Pb were within the range of 10−6 −10−5 indicating minimal-to-moderate risk of developing cancer based on the USEPA 2019 standard. Long-term intake of agricultural food crops contaminated with pesticide-derived heavy metals could constitute a national health risk. Heavy metals in pesticides should be screened and monitored regularly.