Histopathological effects of environmentally relevant amounts of Bisphenol A on the gills, adductor muscles and digestive gland of laboratory-reared Corbicula fluminea

Abstract

Bisphenol A (BPA) is a commonly occurring industrial chemical that was evaluated by the U.S. Department of Health and Human Service (2008) for reproductive and developmental toxicity. Its toxicity was analyzed through its histopathological effects on the tissues of the gills, digestive glands and adductor muscles of Corbicula fluminea, a freshwater clam widely used as a bioindicator for its high adaptability to various environments. Forty Corbicula fluminea were acclimatized for fourteen days and subsequently exposed to set-ups with 1 µg/L, 2 µg/L and 3 µg/L of BPA for twenty-one days, after which, the soft tissues were dissected and processed for sectioning. The histological alterations observed in the tissues of Corbicula fluminea were vacuolations, necrosis, lamellar deformation, hyperplasia, loss of epithelium, necrosis, tubular alteration, neoplasia, hemocyte infiltration, hypertrophy and pyknosis and were scored using an index described by Costa, Carreira, Costa & Caeiro (2013). Statistical results revealed that there were significant differences in the histological alterations observed in the gills across all the experimental and control set-ups while there was no significant difference in the histological alterations observed in all the adductor muscle treatment set-ups and between the 2-µg/L and 3-µg/L set-ups. In addition to that, the three soft tissues showed the greatest amount of alterations in the 3 µg/L set-up with the digestive glands being the most damaged and the adductor muscles being the least damaged. This type of histopathological analysis provides useful information in studying the health of aquatic ecosystems and of economically important organisms such as C fluminea