Assessment of heavy metal pollution from flooded rice farms in Hadejia LGA of Jigawa State Nigeria: an impact of climate change.

This study assessed heavy metal contamination in flooded rice farmlands of Hadejia Local Government Area, Jigawa State, Nigeria, with the aim of investigating the impact of perennial flooding on metal accumulation in soils and rice grains. The research addresses a significant data gap in environmental and public health surveillance within the region. A total of 50 surface soil and 50 rice grain samples were collected and analyzed using microwave plasma-atomic emission spectroscopy (MP-AES), validated by atomic absorption spectroscopy (AAS), to determine the concentrations of Zn, Cd, Fe, Cu, Ni, As, Pb, Mn, and Cr. Due to non-normal data distribution, median values were used for the analysis. While most heavy metals were within the permissible limits, arsenic (As) exceeded its maximum allowable concentration (MAC) in soil by 77.5% and surpassed its weekly tolerable intake limit in rice by four orders of magnitude, posing a significant health risk. The contamination was attributed to mine tailings, abandoned pits, agricultural residues, and industrial discharges from nearby regions. Pollution indices indicated particularly high risks from Cd and As. The study recommends detailed geochemical mapping to trace arsenic sources and the adoption of low-arsenic-absorbing rice varieties to reduce dietary exposure and enhance food safety.