Ambient Concentrations of PCDDs/PCDFs (PolychlorinatedDibenzodioxins/Dibenzofurans) in the South Coast Air Basin

摘要

The study characterized ambient concentrations of polychlorinated dibenzodioxinsand dibenzofurans (PCDDs and PCDFs, or dioxins) at several sites in the South Coast Air Basin. The sites represented industrial, commercial, residential, and background locations, some near known emission sources. Ambient monitoring results are presented as congener distributions at the various sampling sites, along with data on air mass flows. Ambient air was sampled with high-volume samplers which employed both a glass fiber filter to collect particulate matter, and a polyurethane foam trap to collect semivolatile organic compounds. Four seasonal sampling sessions were conducted in an attempt to approximate annual averages at each site. High resolution mass spectrometry was used to analyze the samples for the fifteen dioxin and furan congeners chlorinated in the 2, 3, 7, and 8 positions. Overall dioxin levels are reported as 'detected toxic equivalents', based upon a determination by the State Department of Health Services.