Heavy Metals Analysis in Water and Some Vegetables Samples From Michika Town, Michika Local Government Area, Adamawa State

The contamination of water sources and edible crops with heavy metals poses a significant threat to environmental quality and public health, particularly in regions with increasing anthropogenic activities and limited regulatory oversight. This study investigates the concentration and distribution of selected heavy metals—Zinc (Zn), Copper (Cu), Manganese (Mn), Chromium (Cr), and Lead (Pb)—in water and commonly consumed leafy vegetables in Michika Local Government Area, Adamawa State, Nigeria. Water samples were collected from boreholes and hand dug wells in three communities (Zaibadari, Sengere, and Central), while vegetable samples—spinach (Amaranthus spp.), pepper (Capsicum spp.), roselle (Hibiscus sabdariffa), and cabbage (Brassica oleracea)—were procured from farms and markets in Michika town. Standard wet digestion procedures were applied, and the concentration of metals was determined using Atomic Absorption Spectrophotometer (AAS). Physicochemical analysis of water samples revealed pH values ranging from 8.00 to 9.00, within World Health Organization (WHO) permissible limits. However, elevated levels of Total Dissolved Solids (TDS) (201.00 ± 1.41mg/L to 388.00 ± 1.41 mg/L) and Electrical Conductivity (E.C) (110.00 ± 0. 01 to 1100.00 ± 0.70) above the WHO permissible limits were observed in some locations, indicating potential contamination from agricultural runoff, domestic wastewater, and lingering impacts of insurgency-induced infrastructural damage. Heavy metals analysis showed detectable concentrations of Zn, Cu, and Mn, with Mn levels (0.25 ± 0.01 mg/L to 1.50 ± 0.01 mg/L) in certain samples surpassing the WHO threshold of 0.4 mg/L. Chromium and Lead were below detection limits in both water and vegetable samples. In contrast, vegetable samples exhibited considerable variation in heavy metal accumulation, with some samples showing elevated levels of Zn and Mn, reflecting uptake from contaminated soils or irrigation sources. The findings suggest that while immediate toxicological threats from Cr and Pb are minimal, chronic exposure to elevated levels of Zn and Mn through water and dietary intake could pose long-term health risks. This study recommends the need for comprehensive environmental monitoring, improved agricultural practices, and public awareness campaigns to reduce exposure to heavy metals in the region.