PT07 Contaminated Harbor and River Sediment
Exhibit Hall
8:00 AM - Tuesday, 11 November 2003
(PT128) Health Risk Assessment and Distribution of Bioavailable Metals at the Portland Harbor Superfund Site, Oregon.
Anderson, K1, Krissanakriangkrai, O1, Johnson, E1, Adam, R1, 1 Oregon State University, Corvallis, Oregon, USA
ABSTRACT- Portland Harbor was placed on the U.S. EPA National Priorities List in December 2000. Substances found in the Harbor, harmful to human and aquatic organisms, include several semivolatile organic compounds and heavy metals. The Superfund site extends about 6 miles from Swan Island, down river to the confluence with the Columbia River. About 2 million people who live in and nearby Portland use the Willamette River and Portland Harbor for transportation and recreational purposes. Humans can be exposed to contaminated metals from eating fish and shellfish. Furthermore, contacting or ingesting contaminated water in Willamette River could pose a public threat. The purpose of this study was to determine bioavailable trace metals in Willamette River as well as to predict the magnitude of contaminants associated with adverse effects to human. The study location is an 18-mile stretch on the Willamette River. Water samples were grabbed from 10 sites along RM 1 to 18.5, including the Superfund site. Diffusive gel thin-films were deployed at the same sites as water grab sample to sample the bioavailable fraction of metals. Samplers were deployed for 7-21 days within the main river channel, at specific distances from the river bottom. Bioavailability and toxicity of trace metals to aquatic organisms depend on free-ion activities. Anodic stripping voltammetry measures only the ionic-labile metals. Concentrations of chromium detected from these sites were in the range of 1 to 4 ppm which exceeds the US.EPA primary drinking water regulation (0.1ppm) and continuous criteria concentration for aquatic freshwater (0.074 ppm). Trace metals were also analyzed in 3 fish species (Smallmouth Bass, Black Crappie, and Carp) to determine human health risk assessment from fish consumption. Copper, zinc, chromium and arsenic in fish were detected in the range of 0.5 to 4ppm. Therefore, adverse health effect may occur and remediation is needed.
Key words: risk assessment, bioavailable metals, diffusive gel thin-film, anodic stripping voltammetry