Release of polychlorinated biphenyls (PCB) in a salt-wedge estuary as induced by dredging or contaminated sediments.

An evaluation of the input of polychlorinated biphenyls (PCB) in the Duwamish River, Seattle, Wash., resulting from the dredging of contaminated sediments is presented. The mean concentrations of PCB during the monitoring period were 12.8 to 24.5 ng/liter in water and 1.03 to 1.77 microgram/g dry weight in suspended particulate matter. These values were within the ranges normally observed in the river, suggesting that the dredging operations did not induce a significant PCB pulse of potential hazard to the estuary. The fractionation of PCB in suspended particulate matter was determined by computing component concentration ratios, KN(d). These quantities indicate an enrichment factor of 10(5) from ambient water. Based on the ambient PCB load and normal discharge, the input of PCB into Puget Sound via the Duwamish River was estimated to be 36 kg/year.