ASSESSING BIOAVAILABILITY OF HEAVY METALS IN TURKEY CREEK, JOPLIN, MO

Heavy metal contamination can pose a serious threat to aquatic biota in waterways, soil microbes, plants and even has the potential to bioaccumulate and threaten human health. Joplin, MO, a historic mining town and part of the Tri-State Mining District, had extensive mining operation for over 150 years. Mine waste drainage, smelter fallout, and chat pile runoff distributed lead, zinc, and cadmium over the region in dangerous concentrations. The area has been remediated in some parts, but complete remediation could take decades. Turkey Creek, adjacent to where an old lead smelter used to be, will serve as the site to collect sediments for sequential extractions to assess mobility and bioavailability of heavy metals. For a preliminary appraisal of metal content, 22 sediment samples were collected along Turkey creek and sent to a commercial laboratory to be analyzed for total metal concentration. Three samples reported high lead concentrations (>340ppm and up to 471ppm). Two samples reported high zinc concentrations (>10,000ppm) and two samples reported high cadmium concentrations (>100 ppm). However, total concentration alone does not fully characterize the sediments, and sequential extractions must be performed to know what amount of the heavy metals are in the various chemical fractions. These and additional samples that will be collected will have two extractions performed on them: (1) exchangeable metals bound to carbonates extraction and (2) iron-manganese oxide extractions. These extractions will be performed at MSU labs. To further the characterization, magnetic susceptibility, size fractionation and organic matter (loss of ignition) of the sediments will be determined. This data analysis will allow evaluation of the success of previous remediation efforts in the Joplin area and will identify areas which are in the most need of further remediation.