Impacts of pharmaceuticals and personal care products mixtures in marine bivalves

• Autor(a) principal: Lopes, Joel Martins
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/33452
• topic: Oxidative stress; Metabolism; Histopathological alterations; Behavioural alterations; Emerging contaminants

Mixture of contaminants often determine biological responses of marine species, making difficult the interpretation of toxicological data. Among these contaminants are pharmaceuticals and personal care products (PCPs) such as 17 α-ethinylestradiol (EE2) and Sodium Lauryl Sulfate (SLS). Due to their large production and everyday use by the human population, they will eventually enter the marine environment, manly through wastewater. Once in the marine environment EE2 and SLS may interact with organisms and induce toxic effects, in bivalves. Beside contamination, organisms are also exposed to climate change, responsible for a gradual increase in the ocean temperature, which can cause physiological and biochemical impairments in aquatic organisms as well as increased the sensibility of organisms to pollutants. Furthermore, it is already reported that warming may change the properties and toxicity of pollutants. The present study evaluated the effects of EE2 under warming conditions and EE2 and SLS in Mytilus galloprovincialis at control temperature. For this, mussels were distributed into two climatic rooms to maintain organisms at two different temperatures: 17 ± 1 and 21 ± 1 °C. The tested concentrations used resemble low to highly polluted sites for the first experiment with EE2 at 17 and 21 °C were 5.0; 25.0; 125.0 and 625.0 ng/L, at the second experiment 125.0 ng/L for EE2, 4.0 mg/L for SLS and the mixture of both substances (EE2+SLS) at control temperature. The exposure lasted 28 days and at the end, concentrations in mussel’s tissues, histopathological alterations, biochemical, behavioural and quantitative RT-PCR analyses were evaluated. Results obtained clearly showed when organisms are exposed to EE2 at two different temperatures, higher toxic impacts are revealed under warming conditions in comparison to mussels exposed control temperature, suggesting that temperature rise may significantly increase the sensitivity of bivalves indicating an interactive effect induced by the combination of EE2 and temperature. This is demonstrated by the histopathological alterations, inhibition of superoxide dismutase (SOD), greater lipid peroxidation (LPO) levels, higher metabolic capacity and decreased acetylcholinesterase (AChE) activity in the presence of EE2 at 21 °C compared to mussels exposed to control temperature. Furthermore demonstrates, impacts of EE2 and SLS, acting alone or combined, to the bivalve M. galloprovincialis. Results showed that both contaminants represent a threat to mussels. EE2 is more harmful to females and SLS to males, causing alterations on their behaviour, metabolic capacity, and oxidative status. Nevertheless, it was not evident a synergistic effect when both contaminants were acting together. Moreover, regarding histopathological alterations in bivalve’s gills with both contaminants induced negative impacts in mussels, corroborating qPCR analysis that showed clear response to contaminants exposure. The results obtained highlight the harmful capacity of both contaminants but further research on this matter is needed, namely considering different climate change scenarios.