C.O. ASEMOTA

Food processing methods, particularly mechanical grinding, have been identified as potential sources of heavy metal contamination in daily diets. This study assessed the concentrations and health risks of heavy metals introduced into common Nigerian food items (tomato, pepper,melon, beans, groundnut, white and yellow corn, and crayfish) during grinding with various equipment types including blenders, milling machines, hand-crank grinders, mortars, and grinding stones. Heavy metals (Fe, Mn, Zn, Ni, Cd, and Pb) were analyzed using Atomic Absorption Spectrophotometry (AAS), and potential health risks were evaluated using Estimated Daily Intake (EDI) and Target Hazard Quotient (THQ) models. Results revealed elevated levels of essential metals such as Fe, Mn, and Zn, with concentrations highest in foods ground with older milling machines and mechanical grinders, reflecting increased leaching due to metallic wear. Toxic metals (Pb and Cd) were mostly below detection limits, indicating minimal immediate toxicity but potential for chronic accumulation. Fe showed the highest EDI (up to 5.35 mg/kg/day in hand-crank grinder samples), while THQ values exceeded 1.0 in several processed beans samples, suggesting possible non-carcinogenic risk upon prolonged exposure.Traditional grinding methods (mortar and pestle) exhibited significantly lower contamination levels compared to mechanical ones. These findings highlight that metal leaching from food processing equipment constitutes a significant but often overlooked route of dietary exposure to heavy metals in Nigeria.

Food processing methods, particularly mechanical grinding, have been identified as potential sources of heavy metal contamination in daily diets. This study assessed the concentrations and health risks of heavy metals introduced into common Nigerian food items (tomato, pepper, melon, beans, groundnut, white and yellow corn, and crayfish) during grinding with various equipment types including blenders, milling machines, hand-crank grinders, mortars, and grinding stones. Heavy metals (Fe, Mn, Zn, Ni, Cd, and Pb) were analyzed using Atomic Absorption Spectrophotometry (AAS), and potential health risks were evaluated using Estimated Daily Intake (EDI) and Target Hazard Quotient (THQ) models. Results revealed elevated levels of essential metals such as Fe, Mn, and Zn, with concentrations highest in foods ground with older milling machines and mechanical grinders, reflecting increased leaching due to metallic wear. Toxic metals (Pb and Cd) were mostly below detection limits, indicating minimal immediate toxicity but potential for chronic accumulation. Fe showed the highest EDI (up to 5.35 mg/kg/day in hand-crank grinder samples), while THQ values exceeded 1.0 in several processed beans samples, suggesting possible non-carcinogenic risk upon prolonged exposure. Traditional grinding methods (mortar and pestle) exhibited significantly lower contamination levels compared to mechanical ones. These findings highlight that metal leaching from food processing equipment constitutes a significant but often overlooked route of dietary exposure to heavy metals in Nigeria.

This study was carried out to determine heavy metal levels and distribution in soils and earthworm in selected primary and nursery schools namely, Owina school, Olua school, Ubth staff school, Calvary crown and Impact academy, located in Benin City, Nigeria. A total of ten (10) soil sample and thirty (30) earthworms were collected from five school; particularly the playground area in Benin City, Nigeria. Seven (7) heavy metals were examined in this study namely: Iron, Zinc, Chromium, Copper, Lead, Nickel and Cadmium. The mean concentration of metals in soils ranged from 14.56-121.3 mg/kg for Fe, 5.98-43.22 mg/kg for Zn, 1.56 -15.44 mg/kg for Cr, 0.73 - 19.26 mg/kg for Cu, 0.38 - 1.44 mg/kg for Pb, 2.16 - 4.28 mg/kg for Ni and 0.012 - 0.04 mg/kg for Cd. While the mean concentration of metals in earthworm ranged from 49.45-95.73 mg/kg for Fe, 18.93 - 108.7 mg/kg for Zn, 1.86 - 5.74 mg/kg for Cr, 6.47 - 50.27 mg/kg for Cu, 0.23 - 0.63 mg/kg for Pb, 0.22 - 0.62 mg/kg for Ni and 0.04 - 0.14 mg/kg for Cd.The value recorded in soils were observed to be higher in comparison to the values in earthworms. The highest mean value in soils was recorded in Owina school and the lowest was recorded in Ubth staff school while the highest mean value in earthworm was recorded in Olua school and the lowest in Impact academy. Much attention should be given to heavy metals because oftheir high toxicity potential in children, their widespread use and their prevalenc