The effect of temperature on Triclosan and Lead exposed mussels.

Interest on the effects of emerging contaminants over aquatic organisms has increased in the last years. Nonetheless, the toxic action of classical natural and anthropogenically-driven metals has also to be monitored, especially because they reflect real environmental situations. For that, in the present study we focused on the effects on the marine mussel Mytilus galloprovincialis of the personal care product Triclosan (TCS) and Lead (Pb), as toxic metal, under separate and co-exposure situations at environmentally relevant concentrations: TCS (1 µg/L) and Pb (50 µg/L). The consideration of an additional factor such as an increase in ambient temperature was also included to provide a forecasted scenario of climate change: from the ambient temperature at actual conditions (17 °C) to a predicted warming situation (22 °C). Water chemical characterization and some physical properties and bioaccumulation of TCS and Pb in mussels at the end of the experiment (28 days) was considered. The parameters followed up comprise the energy related system production (electron transport system) and glycogen and protein reserves. Antioxidant enzymatic defences towards reactive oxygen species (ROS) and the consequences of ROS damage over endogenous lipids (LPO) and proteins (PC). Overall the results suggested only particular responses to chemical exposures at 17 °C whereas at 22 °C the detoxification machinery was set up and this prevented the occurrence of LPO. Nonetheless, PC formation occurred under Pb and TCS + Pb co-exposure at the highest temperature. Due to the complexity of the study: 4 chemical conditions, 2 temperatures and 10 biomarkers considered, a principal component ordination (PCO) analysis was included. The results of this integrative analysis confirmed a clear effect of the temperature, more responsiveness to drugs at 22 °C and in all likelihood due to Pb presence.