No abstract

No abstract

No abstract

Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs), previously under reported classes of organic contaminants, were determined in sediment, water, and freshwater biota in an urban creek in Canada. SDPAs and BZT-UVs were frequently detected in all matrices including upstream of the urban area in a rural agricultural/woodlot region, suggesting a ubiquitous presence and bioaccumulation of these emerging contaminants. Spatial comparisons were characterized by higher levels of SDPAs downstream compared with the upstream, implying a possible influence of the urban activities on the antioxidant contamination in the sampling area. In sediment, 4,4'-bis(α,α-dimethylbenzyl)-diphenylamine (diAMS), dioctyl-diphenylamine (C8C8), and dinonyl-diphenylamine (C9C9) were the most dominant congeners of SDPAs, with concentrations up to 191 ng/g (dry weight, d.w.). Benthic invertebrates Crayfish (Orcoescties spp.) had larger body burdens of SDPAs and BZT-UVs compared to pelagic fish (hornyhead chub (Nocomis biguttatus) and common shiner (Luxilus cornutus)) in the creek and partitioning coefficients demonstrated that sediment was the major reservoir of these contaminants. This is the first report of bioaccumulation and partitioning behaviors of SDPAs and BZT-UVs in freshwater environments.

No abstract

No abstract

The paper describes a simple and quantitative method for monitoring non-conjugated 17β-estradiol (E2) and its metabolites estrone (E1) and estriol (E3) as environmental contaminants in municipal sewage effluents. Estrogens were preconcentrated and cleaned up by solid-phase extraction using a reversed-phase c18cartridge. They were derivatized with pentafluoropropionic acid anhydride, and the products were analyzed by gas chromatography/mass spectrometry. Recoveries from spiked distilled water and sewage were better than 87% at fortification levels of 100 and 20 ng/L. For a 1 L sewage sample and a concentration factor of 5000, detection limits were 5 ng/L for E1 and E2 and 10 ng/L for E3. In a brief survey of Canadian wastewater, these estrogens were detected in many raw sewage and effluent samples at concentrations ranging from 6 to 109 ng/L for E1, from <5 to 15 ng/L for E2, and from <10 to 250 ng/L for E3.

A large-scale study on bisphenol A (BPA) contamination in Canadian municipal and industrial wastewater and sludge has been completed. A total of about 200 samples were collected, including those from 31 sewage treatment plants and 15 pulp and paper mills across Canada, as well as 13 industrial facilities in the Toronto area. The samples were extracted by previously developed solid-phase and supercritical carbon dioxide extraction procedures and were analyzed by gas chromatography-mass spectrometry. BPA contamination was detected in all of the 72 sewage samples, with concentrations ranging from 0.080 to 4.98 µg/L (median 0.329 µg/L) for the influent, and from 0.010 to 1.08 µg/L (median 0.136 µg/L) for the effluent. Of the 36 influent/effluent sample pairs studied, BPA in the influent is removed by the sewage treatment process at a median reduction rate of 68%. Levels of BPA accumulation in sewage sludge, for the 50 samples tested, ranged from 0.033 to 36.7 µg/g, on a dry weight basis. A wide range of BPA concentrations, from 0.23 to 149.2 µg/L, were observed for the wastewater collected from selected industrial facilities in the Toronto area. The more contaminated samples came from the sectors of chemicals and chemical products, commercial dry cleaning, as well as packaging and paper products. Based on these data, on-site releases of BPA by industrial facilities seem to be much more widespread than the National Pollutant Release Inventory (NPRI) database has suggested. While relatively high levels of BPA were found in some of the primary treated effluent collected from the deinking mills, BPA concentrations in the secondary treated effluent of all pulp and paper mills were low, with a range from < 0.005 to 0.0406 µg/L. Except for the samples derived from a few deinking mills, BPA contaminication in pulp and paper mill sludge was either low or undetected.