|
2C - Biomarkers (TUP/100) In vitro dioxin toxicities of photoproducts formed by irradiation of monochlorophenols in ice and liquid water. Janosek, Jaroslav1, Blaha, Ludek1, Klanova, Jana1, Klan, Petr2, Giesy, John3, Holoubek, Ivan1, 1 RECETOX, Masaryk University, Brno, Czech Republic, Czech Republic2 Faculty of Science, Masaryk University, Brno, Czech Republic, Czech Republic3 Michigan State University, East Lansing, MI, U.S.A. ABSTRACT- Current reports demonstrated that water ice can be a suitable reaction medium for photochemical transformations of organic pollutants and de novo formation of some persistent, bioaccumulative, and toxic compounds (PBTs). We have focused on the characterization of the in vitro potencies of photoproducts of chlorophenols to induce AhR- mediated toxicity in the transgenic rat liver hepatoma cells H4IIE.luc. The irradiation of chlorophenols in liquid water results in the formation of monoaromatic compounds such as pyrocatechol. On the other hand, chlorinated biphenyldiols, dibenzofuran and other polyaromatic compounds are among the major phototransformation products of chlorophenols in the solid ice. Our assessment indicates that iceborne products of both 2- and 4-monochlorophenols can induce significant dioxin toxicities in vitro in micromolar concentrations comparable to known inducers of AhR, such as many PAHs or PCBs. The results support the model in which significant amount of (PBTs) may be generated by photochemistry of primary pollutants in cold ecosystems and in the upper atmosphere, and may subsequently be released to the environment. Acknowledgements: This work was supported by GACR 525/00/D101 and 205/02/0896 grants. Key words: chlorophenols, photochemistry, dioxin-like toxicity |
