SPATIAL ASSESSMENT OF HEAVY METALS IN WATER BODIES FROM THE MIDCONTINENT REGION OF USA: INSIGHTS ON HYDROGEOCHEMISTRY, ENVIRONMENT, AND HEALTH

This study examines the distributions of heavy metals (As, Al, Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn) in different water bodies (pond, well, lake, river, beach) from three Midcontinent region (Missouri, Iowa, and Nebraska) of USA to determine their source and environmental health implications. The water sample collection was carried out during the Spring 2024 by sampling three replicas of the water along the latitude (38.9061° N) and longitude (94.4735° W) within the three regions. A total of 92 water samples were collected from different water bodies from the farmland, residential, and industrial areas. By region, 62, 21, and 9 were water taken from Missouri, Iowa, and Nebraska, respectively.

The preliminary results of the heavy metals obtained based on ICP method and standard procedure were compared with other national and international standards. The analytical calibration curves plotted, the linearity of data, and value of correlation coefficients for each toxic and essential metal shows that most of the Fe and Al concentrations are above the EPA threshold limit ((Fe = 295.94µg/L) and (Al = 308.22 µg/L)) whereas, As, Cd, Co, Cr, Cu, Ni, Pb, and Zn are below the threshold limit in the selected regions. In addition, As, Cd, and Pb concentrations were noted to be slightly high (not above the EPA threshold) in 3 water bodies (creek, lake, and pond) in Nebraska and Iowa, but their concentrations are low in most of the water collected in Missouri.

Given that the current results showed that the concentrations of most heavy metals in the water samples were within the EPA threshold limit, no health issue was assessed. However, the low detection limit of the heavy metals could be that their source may be far off from most of the water bodies or proper EPA regulations are being adhered to by the public. Our future study will focus on analyzing a few water and soil samples (creeks, lake, and pond) in Iowa and Nebraska to look at the physicochemical parameters (alkalinity, nitrate, anions, conductivity, etc.) and the source of secondary contaminants to infer sediment and water interactions and their environmental implications on human and ecosystems health.