Tetrachlorodibenzo-p-dioxin (2,3,7, was measured in sediments and suspended matter samples from estuaries adjacent to an industrial site in Newark, NJ, where chlorinated phenols had been produced. Present day and recent historical levels of 2,3,7,8-TCDD contamination were established through the use of radionuclide time tracers (7Be, 137Cs). Concentrations up to 21000 parts per trillion (ppt) were found in sediments deposited near the site. Pre-1950 production of DDT at the same industrial site provided another sensitive pollutant source tracer. The total deposition of 2,3,7,8-TCDD in Newark Bay sediments since the late 1940s has been approximately 4-8 kg, among the largest releases documented to date. Sediments dredged from estuaries in this region have been disposed of on land surrounding Newark Bay and at a coastal ocean dumpsite.

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A capillary column gas chromatographic/high resolution mass spectrometric method was developed for the determination of monobromopolychlorodibenzo-p-dioxins (BPCDDs) in environmental samples. The mass spectrometer was operated at high resolution (> 10,000) in the selected ion monitoring mode with magnet switching among tetra through octa groups to achieve low or subpicogram detection limits. Standard BPCDDs (tetracongener through octacongener groups) were utilized to measure accurately the mass spectrometric relative response factors for these compounds, and linear calibrations were achieved by using these standard compounds at different concentrations. The method detection limit is low or sub-parts-per-trillion levels for BPCDDs, the accuracy better than 80% and the precision better than ± 10%. Quantification of BPCDDs and preliminary identification of some specific BPCDD isomers in fly ash samples are also reported.