|Abstract or Summary
- An interdisciplinary study, USGS Columbia River Contaminants and Habitat Characterization (ConHab) project, is underway to investigate transport pathways, chemical fate and effects of polybrominated diphenyl ethers (PBDEs) and endocrine disrupting chemicals (EDCs) in aquatic media and the foodweb in the lower Columbia River. Polar organic chemical integrative samplers (POCIS) and semipermeable membrane devices (SPMDs) were co-deployed at each of 10 sites to provide a measure of the dissolved concentrations of select PBDEs, chlorinated pesticides, and other EDCs. PBDE-47 was the most prevalent of the PBDEs detected. Numerous organochlorine pesticides, both banned and current-use, were measured at each site including hexachlorobenzene, pentachloroanisole, dichlorodiphenyltrichloroethane (DDT) and its degradates, chlorpyrifos, endosulfan, and the endosulfan degradation products. EDCs commonly detected included a series of polycyclic aromatic hydrocarbons (PAHs), fragrances (galaxolide), pesticides (chlorpyrifos and atrazine), plasticizers (phthalates), and flame retardants (phosphates). The site near Columbia City tended to have the highest concentrations of contaminants in the Lower Columbia River.
Resident largescale suckers (Catostomus macrocheilus) were collected at three of the ten sites. Brain, fillet, liver, stomach, and gonad tissues were analyzed. Concentrations of halogenated compounds in tissue samples ranged from <1 to 400 ng g-1 wet tissue. PBDEs, organochlorine pesticides, DDT and its degradates, and polychlorinated biphenyls (PCBs) were detected at all sites in nearly all organs tested. Concentrations increased moving downstream from Skamania to Columbia City to Longview. Chemical concentrations were highest in livers, followed by brain, stomach, gonad, and fillet. PBDE congeners most frequently detected and at the highest concentrations were BDE47 > BDE100 > BDE154 > BDE153. These congeners are some of the major constituents of the commercial penta-BDE formulation. Results support the hypothesis that contaminant concentrations in the environment correlate to bioaccumulation in the foodweb. The fish concentrations will be compared to concentrations in other levels of the foodweb and to biomarker results also determined as part of the ConHab project to improve understanding of bioaccumulation and effects of these contaminants in the lower Columbia River.