SOURCES AND DISTRIBUTION OF POLYCHLORINATED TERPHENYLS AT A MAJOR US AERONAUTICS RESEARCH FACILITY

High concentrations of an unusual, complex mixture of chlorinated comp ounds were discovered in sediments and oysters near a federal aeronaut ics facility during implementation of a pollutant screening protocol. The mixture was identified as Aroclor 5432, a polychlorinated terpheny l (PCT) formulation, produced in the US until 1972. PCTs, particularly low chlorinated mixtures, have rarely been reported in the environmen t, despite significant manufacture and usage. Releases were traced to two outfalls. Creek sediments downstream of one contained concentratio ns as high as 200,000 mu g/kg (dry weight basis); those in indigenous oysters reached 35,000 mu g/kg, indicating significant bioavailability and bioaccumulation potential. Subsequent work showed that PCTs were widely disseminated in marsh grass, crabs, and fish. PCTs, PCBs, and m ercury were also detected in storm drain lines entering these outfalls . The lines received input from both storm water and research building s. Historical hydraulic fluid leaks and in-service compressor fluids i n some buildings contained PCTs and PCBs. Contaminated materials on-si te were removed to minimize pollutant spread. Aroclor 5432 usage, most likely as compressor/hydraulic fluid additives, probably ended about ten years prior to its on-site detection. in terms of biological effec ts, intraperitoneal injection of fish with Aroclor 5432 induced cytoch rome P-4501A (CYP1A) and ethoxyresorufin O-deethylase (EROD) activity to a similar degree as PCB Aroclor 1254 and to a greater extent than P CT Aroclor 5460. The presence of high concentrations of PCTs contribut ed to the facility being included on the National Priorities List. It subsequently became the first US federal facility to sign a Federal Fa cility Agreement, identifying cleanup responsibilities, prior to forma l listing.