Sources and Distribution of Polychlorinated Terphenyls at a Major US Aeronautics Research Facility.

Abstract

/ High concentrations of an unusual, complex mixture of chlorinated compounds were discovered in sediments and oysters near a federal aeronautics facility during implementation of a pollutant screening protocol. The mixture was identified as Aroclor 5432, a polychlorinated terphenyl (PCT) formulation, produced in the US until 1972. PCTs, particularly low chlorinated mixtures, have rarely been reported in the environment, despite significant manufacture and usage. Releases were traced to two outfalls. Creek sediments downstream of one contained concentrations as high as 200,000 |gmg/kg (dry weight basis); those in indigenous oysters reached 35,000 |gmg/kg, indicating significant bioavailability and bioaccumulation potential. Subsequent work showed that PCTs were widely disseminated in marsh grass, crabs, and fish. PCTs, PCBs, and mercury were also detected in storm drain lines entering these outfalls. The lines received input from both storm water and research buildings. Historical hydraulic fluid leaks and in-service compressor fluids in some buildings contained PCTs and PCBs. Contaminated materials on-site 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 effects, intraperitoneal injection of fish with Aroclor 5432 induced cytochrome P-4501A (CYP1A) and ethoxyresorufin O-deethylase (EROD) activity to a similar degree as PCB Aroclor 1254 and to a greater extent than PCT Aroclor 5460. The presence of high concentrations of PCTs contributed to the facility being included on the National Priorities List. It subsequently became the first US federal facility to sign a Federal Facility Agreement, identifying cleanup responsibilities, prior to formal listing.KEY WORDS: Polychlorinated terphenyls; Aroclor; Contaminated sediments; Hydraulic fluid; Enzyme induction; Polychlorinated biphenyls