Alkylphenol ethoxylate degradation products in land-applied sewage sludge (biosolids).

Alkylphenol ethoxylates, widely used in commercial and household detergents in the United States, can degrade during the wastewater treatment process to more toxic, estrogenic, and lipophilic compounds. These include octylphenol (OP), nonylphenols (NPs), nonylphenol monoethoxylates (NP1EOs), and nonylphenol diethoxylates (NP2EOs). These compounds have received considerable attention due to their acute toxicity and ability to disrupt the endocrine system. In Europe, regulations have been established to control their impact on the environment. In this study, biosolids derived from all 11 U.S. wastewater treatment plants examined contained detectable levels of OP, NPs, NP1EOs, and NP2EOs. Nine exceeded the current Danish land application limit (30 mg/kg; sum of NPs, NP1EOs, and NP2EOs) by 6-33x. NPs were the major component, and their concentrations therein ranged from 5.4 to 887 mg/kg (dry weight). OP, reportedly 10-20x more estrogenic than NP, was detected in these same nine biosolids at levels up to 12.6 mg/kg. Three biosolids were also subjected to the U.S. Environmental Protection Agency Toxicity Characteristic Leaching Procedure Method 1311. NPs and NP1EOs were both detected in the leachate; the former at concentrations from 9.4 to 309 microg/L. On the basis of effect levels published in the literature, alkylphenol ethoxylate degradates in U.S. biosolids may cause adverse environmental impacts.

Polybrominated diphenyl ether flame retardants in Virginia freshwater fishes (USA).

Polybrominated diphenyl ethers (PBDEs) were examined in fish fillets collected from two large Virginia watersheds. Emphasis was on the tetra- to hexabrominated congeners since these exhibit the greatest bioaccumulation and toxicological potentials. These congeners are dominant constituents of Penta-, a commercial PBDE product used to flame retard polyurethane foam. In 1999, North America accounted for98% of global Penta-demand. Concentrations of total tetra- to hexabrominated congeners in fillets ranged from <5 to 47,900 microg/kg (lipid basis). BDE-47, one of the two major constituents of Penta-, was detected in 89% of samples and contributed 40-70% of the total PBDEs observed. Concentrations of BDE-99, the second major constituent of the Penta- commercial mixture, were much lower in fish. While some differences in PBDE profiles between fish species were apparent, dominant congeners were consistent with those in surficial sediments from the Virginia sites and recently published data for U.S. air samples. PCB and PBDE concentrations in fish were generally associated. These factors point to exposure from nonpoint sources. Exceptions existed, likely due to inputs from local sources. The Virginia study area has historically served as a center for furniture and textile manufacturing, although polyurethane foam production here has been limited.