ABSTRACT
The synthetic hormone 17α ethinyl estradiol (EE2) is a molecule widely used in female contraceptives and recognized as a contaminant of attention (Watch List) in the European Union due to its high consumption, endocrine effects and occurrence in aquatic environments. Its main source of introduction is domestic sewage where it can be associated with other contaminants such as microplastics (MPs). Due to their characteristics, they can combine with each other and exacerbate their isolated effects on biota. This study evaluated the combined effects of microplastics (MPs) and 17α ethinylestradiol (EE2) on two tropical estuarine invertebrate species: Crassostrea gasar and Ucides cordatus. Polyethylene particles were spiked with EE2 and organisms were exposed to three treatments, categorized into three groups: control group (C), virgin microplastics (MPs), and spiked microplastics with EE2 (MPEs). All treatments were evaluated after 3 and 7 days of exposure. Oysters exhibited changes in phase 2 enzymes and the antioxidant system, oxidative stress in the gills, and reduced lysosomal membrane stability after exposure to MPs and MPEs. Crabs exposed to MPs and MPEs after seven days showed changes in phase 1 enzymes in the gills and changes in phases 1 and 2 enzymes in the hepatopancreas, such as disturbed cellular health. The combined effects of microplastics and EE2 increased the toxicity experienced by organisms, which may trigger effects at higher levels of biological organization, leading to ecological disturbances in tropical coastal ecosystems.
ABSTRACT
Domestic sewage is an important source of pollutants in aquatic ecosystems and includes both microplastics (MPs) and pharmaceuticals and personal care products (PPCPs). This study sought to assess the biological effects of the interaction between plastic particles and the antibacterial agent triclosan (TCS). The study relied on the swamp ghost crab Ucides cordatus as a model. Herein polyethylene particles were contaminated with triclosan solution. Triclosan concentrations in the particles were then chemically analyzed. Swamp ghost crab specimens were exposed to experimental compounds (a control, microplastics, and microplastics with triclosan) for 7 days. Samplings were performed on days 3 (T3) and 7 (T7). Gill, hepatopancreas, muscle and hemolymph tissue samples were collected from the animals to evaluate the biomarkers ethoxyresorufin O-deethylase (EROD), dibenzylfluorescein dealkylase (DBF), glutathione S-transferase (GST), glutathione peroxidase (GPx), reduced glutathione (GSH), lipid peroxidation (LPO), DNA strands break (DNA damage), cholinesterase (ChE) through protein levels and neutral red retention time (NRRT). Water, organism, and microplastic samples were collected at the end of the assay for post-exposure chemical analyses. Triclosan was detected in the water and crab tissue samples, results which indicate that microplastics serve as triclosan carriers. Effects on the gills of organisms exposed to triclosan-spiked microplastics were observed as altered biomarker results (EROD, GST, GPx, GSH, LPO, DNA damage and NRRT). The effects were more closely associated with microplastic contaminated with triclosan exposure than with microplastic exposure, since animals exposed only to microplastics did not experience significant effects. Our results show that microplastics may be important carriers of substances of emerging interest in marine environments in that they contaminate environmental matrices and have adverse effects on organisms exposed to these stressors.
