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Benzotriazole ultraviolet stabilizers (BUVSs) used in consumer products are raising concerns as new pollutants in the aquatic environment. We determined the agonistic activities of eight BUVSs and a chemically distinct UV absorber (4-methylbenzylidinecamphor) toward the human aryl hydrocarbon receptor (AhR) and thyroid hormone receptors alpha and beta. Although none of the BUVSs showed ligand activity against the thyroid hormone receptors, four of them (UV-P, UV-9, UV-326, and UV-090) showed significant AhR ligand activity. Their half-maximal effective concentrations (EC50) were 130 nM for UV-P, 460 nM for UV-9, and 5.1 μM for UV-090 (a value for UV-326 could not be determined). Of the numerous AhR ligands, it is well-known that those considered nontoxic are quickly metabolized by enzymes such as CYP1A1, which destroys their ability to function as ligands. Accordingly, we established a new yeast assay for simultaneous monitoring of both the strength of AhR ligand activity and ligand degradation by CYP1A1. We found the AhR ligand activities of the above four BUVSs to be stable in the presence of CYP1A1; therefore, they have the potential to accumulate and exert potent physiological effects in humans, analogous to polycyclic aromatic hydrocarbons and dioxins, which are known stable and toxic ligands.

Rice bran was found to effectively adsorb several organic compounds, such as dichloromethane, chloroform, carbon tetrachloride, trichloroethylene, tetrachloroethylene, and benzene. Equilibrium adsorption isotherms conformed to the Freundlich type (log-log linear). The adsorption of dichloromethane and chloroform by rice bran was observed over the range of pH 1-11. Therefore, rice bran is applicable for treatment of wastewater over a wide pH range. Dichloromethane was successfully removed from water samples with an average removal efficiency of 70% after 60 min when rice bran was added to water samples containing from 0.006 to 100 mg/L dichloromethane. The removal of these organochlorine compounds and benzene by rice bran was attributed to the uptake by intracellular particles called spherosomes. Here, we report the results of a fundamental study of the efficiency of rice bran for removal of organochlorine compounds and benzene using a batch system on the laboratory scale, and describe elucidation of the mechanism of removal of these compounds by rice bran.

Perfluorooctanoate (PFOA) are environmental contaminants posing special public health concerns because of their long-term persistence and bioaccumulation in the environment. Fluorotelomer alcohols are volatile and may undergo long-range transport. Air samples were collected at five sites in the Keihan area, Japan: Sakyo, Morinomiya and three sites in Higashiyodogawa. Except for Higashiyodogawa, the highest concentrations of fluorotelomer alcohols (FTOHs) were for 8:2 FTOH (median 447 pg m(-3)) followed by 10:2 FTOH (56 pg m(-3)) and 6:2 FTOH (22 pg m(-3)). In contrast, 8:2 FTOAcryl (median 865 pg m(-3)) and 8:2 FTOH (1,864 pg m(-3)) were both major components in Higashiyodogawa. Compared to data published for North America and Europe, 8:2 FTOH levels are significantly higher in Keihan, suggesting a possible point source.