HEALTH RISK

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 assessed the health risk assessment of surface water from Orhionmwon River, Southern Nigeria. A total of 18 water samples were collected at each location from May 2025 to July 2025. From upstream to downstream, water samples were taken from three locations in accordance with normal guidelines. While certain heavy metals were identified using the method of the association of analytical chemistry, the physicochemical properties of surface water were analysed using normal laboratory procedures. The average mean concentration of physicochemical and heavy metal properties in surface water were 30.12±0.20 (temperature), 6.97±0.13 (pH), 20.00±1.20 (EC), 9.89±0.51 (TDS), 4.50±0.17 (TSS), 14.39±0.48 (TS), 6.38±0.27 (turbidity), 5.76±0.59 (alkalinity), 4.84±0.32 (DO), 3.71±0.08 (BOD), 33.78±11.04 (COD), 6.61±0.78 (chloride), 7.61±2.34 (NO3), 0.47±0.25 (PO4), 1.84±0.19
(SO4), 6.92±0.31 (hardness), 1.80±0.16 (Ca), 0.63±0.10 (Mg), 0.87±0.06 (Na), 1.50±0.08 (K), 1.24±0.08 (Fe), 0.11±0.01 (Cu), 0.61±0.08 (Zn), 0.06±0.01 (Pb), 0.28±0.08 (Mn), 0.05±0.01
(Cr) and 3.96±0.15 (THC) respectively. Cadmium was not detected in the surface water from Orhionmwon River. The summative water quality index (WQI) for the three sampled stations were classified Grade E indicating that the water from Orhionmwon River is unsuitable for drinking (>100). The comprehensive pollution index across the sampled stations were classified as slightly polluted. Non-carcinogenic target hazard quotients (THQs) for oral exposure for the heavy metals were < 1.0 except for THC across the sampled stations, which suggests that consumers of water from these locations may be at high risk of non- carcinogenic illnesses associated with THC contaminants. The hazard index (HI) values for oral exposure shows that (HI > 1) which indicates that the consumption of the water predisposes them to potential health risk. The result for the integrated carcinogenic risk (ICR) values classified the surface water from Orhionmwon River as Grade VI (high risk – 10 -3) which calls for immediate attention and adequate action and should be further investigated for heavy metals such as lead and chromium

Industrial effluents are significant contributors to environmental pollution, especially in developing countries where waste treatment is inadequate. Ceramic industries generate wastewater that often contains toxic heavy metals capable of accumulating in the environment and posing serious health risks. This study assessed the concentration of heavy metals in effluents discharged from a ceramic industrylocated in Utesi, Ikpoba-Okha Local Government Area, Edo State, Nigeria, and evaluated the associated potential health risks. Nine effluent samples were collected from three points around the discharge pond over three months. The samples were analyzed for copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), manganese (Mn),and cadmium (Cd) using the Atomic absorption spectrophotometer following standard procedures. Results showed that Mn had the highest concentration (1.07 3.00 mg/L) in July, while chromium was most abundant in June (0.97–1.00 mg/L). Lead and copper ranged between 0.10–0.47 mg/L and 0.10–0.57 mg/L, respectively, while cadmium reached 0.63 mg/L in August. Compared with the WHO and NESREA standards, Cr, Pb, Mn, and Cd exceeded permissible limits. The mean concentration trend was Mn (1.10 mg/L) > Cr (0.58 mg/L) > Pb (0.27 mg/L) > Cu (0.24 mg/L) > Cd (0.22 mg/L) > Ni (0.06 mg/L). Health risk assessment revealed that cadmium posed the highest non-carcinogenic (HQ = 0.43 for children) and carcinogenic risks (CR = 2.62 × 10⁻⁴ for children).

In this study, the levels of tin (Sn), antimony (Sb), iron (Fe), cadmium (Cd), lead (Pb), and zinc (Zn) in soil and vegetables were examined, as well as the potential health risks of eating vegetables obtained from areas around second cemetery, Iyakpen, Benin City, Edo state, Nigeria. Soil samples were collected with hand auger from 0 – 20cm depth, air-dried, powdered, and sieved. Four different vegetables (mango, orange, potato and bitter-leaf) were also were randomly collected from around the cemetery and transported to University of Benin Civil engineering laboratory, Benin City, Nigeria, for sample preparation. The vegetables were washed with distilled water to remove any traces of dirt, separated, air-dried and further dried in oven for 72 h at 65 °C to attain constant weight. The dried leaves were then pounded with a mortar and pestle and converted to powder and stored each in a plastic bag for analysis. The soil and vegetable samples were analyzed with a wavelength dispersive X-ray fluorescence spectrometer (SKYRAY INSTRUMENT EDX3600B). Health risk indication parameters (health risk index, daily intake of heavy metals and target health quotient) were evaluated.