ASSESSMENT OF SELECTED DISSOLVED TRACE CONSTITUENTS IN SHALLOW GROUNDWATER AS A POSSIBLE CAUSE OF ANOMALOUS HEALTH DISTRIBUTIONS IN PRAIRIE GROVE, ARKANSAS

Trace constituents in the environment have been linked to numerous anomalous health distributions throughout the U.S. and the world. Prairie Grove, Arkansas, is one such location, and although there is disagreement between experts from state agencies and citizens’ groups as to how “anomalous” or statistically relevant the health problems are in Prairie Grove, the fact remains that more than 140 cases of disease exist from a total population of about 3000 people. These cases are consistent with high concentrations of selected trace constituents found in the groundwater, especially arsenic, copper, and zinc. Long-term arsenic exposure can cause cancer, skin problems, birth defects, reproductive problems, and damage the nervous and circulatory systems. Elevated levels of zinc can cause skin irritations, stomach cramps, vomiting, nausea and anemia. High levels of copper can cause intestinal distress, anemia, and kidney and liver damage. The suspected source of the abnormally high trace metal concentrations is chicken litter that is spread on fields in the surrounding area as an organic fertilizer. Chicken feed is amended with these additives, and a portion is excreted and is present in the litter. Typically, these trace constituents have low solubilities in the range of prevailing groundwater conditions, but they may be mobilized as geochemical conditions change. This study describes a field and lab project conducted at the University of Arkansas Research Experience for Undergraduates (REU) program funded by NSF. Its objective is to assess the likelihood of a transport pathway for arsenic, copper, and zinc via water in the Prairie Grove environment. This study focuses on collecting environmental water samples from streams, rivers, springs and existing wells in the area and analyzing them using atomic absorption methods. Previous samples from different hydrologic conditions define a range of expected concentrations, and duplicate samples to state agency and federal labs provide an assessment of reproducibility. The analyses focus on temperature, pH, specific conductance, and concentrations of arsenic, zinc, and copper. Preliminary results suggest groundwater pathways are not the primary transport mechanism, if trace metals are indeed the cause of the anomalous health distributions.