The effect of in vivo co-exposure to estrone and AhR-ligands on estrogenic effect to vitellogenin production and EROD activity.

We evaluated the effect of combination chemical exposure on estrogenic activity, in vivo using Japanese medaka (Oryzias latipes) during co-exposure to estrone (E1) and β-naphthoflavone (βNF) or α-naphthoflavone (αNF). We used E1 because which is one of the major estrogenic substances in the environment, and βNF or αNF are both AhR-ligands and usually used as a model substance of common environmental pollutants such as PAHs from physiological response standpoint. The results of present study demonstrate that both βNF and αNF inhibit the E1-induced production of plasma VTG in a concentration-dependent manner.

Study on the generation of perfluorooctane sulfonate from the aqueous film-forming foam.

Perfluorooctane sulfonate (C(8)HF(17)SO(3)) and perfluorooctane acid (C(8)HF(15)O(2)) are artificial chemicals and have been used all over the world, mainly as water repellent agents, fluorochemical surfactants, coating agents, etc. However, perfluorooctane sulfonate and perfluorooctane acid are environmental contaminants because of their stability, bio-accumulativeness, and long-term persistence in the ecological environment. At the present day, they are diffused all over the world.