PARENT SESSION
PS19 - Bioavailability
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P173) Distribution Profiles of PCBs and Organochlorine Pesticides and the Impact of Seasonal Timing on Contaminant Bioavailability in the Lower Willamette, Oregon.
Anderson, Kim1, Sethajintanin, Doolalai*,1, Johnson, Eugene1, 1 Oregon State University, Corvallis, Oregon, USA
ABSTRACT- Water samples from an 18-mile stretch on the lower Willamette River, Oregon, including the Portland Harbor superfund site have been collected by passive sampling devices (PSDs) during different seasons. The goal of the study is to determine levels and distribution profiles of PCBs and organochlorine pesticides (p,p'-DDT, p,p'-DDD, p,p'-DDE and dieldrin) in the river and to investigate and understand the impact of seasonal timing and episodic events on bioavailability of organochlorine contaminants and on water quality. The major advantage of this passive in-situ technique over conventional water sampling methods is only biologically available organic chemicals will be selectively sampled leading this technique to be a more relevant approach for prediction of toxicity exposure and risk to aquatic organisms. After PSDs are deployed for 1-3 weeks in the river, their exteriors are cleaned up in the field and then undergo a simple sequence of laboratory processes including dialytic recovery, GPC separation and then analyzed by GC-dual column-dual ECD. The preliminary data from dry seasonal event collected during August 2001 suggest the river is contaminated at the industrial and urban areas and less contaminated at undeveloped areas upriver. Estimated water concentration of total DDT ranged from 0.71 to 3.1 ng/L at the sampling sites within the superfund site and ranged from 0.15 to 0.35 ng/L upriver. Estimated water concentrations of PCBs at the sampling sites within the superfund site ranged from 0.19 to 0.46 ng/L and estimated concentrations at the sampling sites upriver ranged from 0.05 to 0.28 ng/L. This data will be spacially and temporally compared with contaminant concentrations for 2001.
Key words: Portland Harbor, PCBs, Organochlorines, Bioavailability