| Abstrakt: |
Simple Summary: Exploring the interactions between organophosphorus flame retardants (OPFRs), microplastics, and freshwater organisms is essential for comprehending the dynamics within freshwater ecosystems to anticipate the potential impacts of organic pollutants and plastic particles. To address this need, the current study examined the exposure effects of 10 mg L−1 of flame-retardant aluminium diethylphosphinate (ALPI), 10 μg mg−1liver of microplastics polyurethane (PU), and their combination on the freshwater planarian Girardia tigrina. Twenty-four-hour exposure of G. tigrina to both ALPI and PU resulted in a sequential effect reflected in a significant reduction in locomotor activity, i.e., exposure may involve a combination of direct neurotoxic effects and the indirect energetic costs associated with the adaptive responses to mitigate the adverse effects. Other biochemical responses, e.g., oxidative stress and metabolic responses, remained unaffected compared to control. Incorporating behavioural indicators into toxicological assays enhances the predictive power of these assessments, enabling a more accurate evaluation of the ecological consequences of pollutant exposure. This integrated approach not only improves our understanding of the complex interactions between organisms and their environment, but also informs more effective strategies for mitigating the detrimental effects of mixtures of pollutants on freshwater ecosystems. Understanding the interplay among organophosphorus flame retardants (OPFRs), microplastics, and freshwater organisms is crucial for unravelling the dynamics within freshwater environments and foreseeing the potential impacts of organic pollutants and plastic contamination. For that purpose, the present research assessed the exposure impact of 10 mg L−1 flame-retardant aluminium diethylphosphinate (ALPI), 10 μg mg−1liver microplastics polyurethane (PU), and the combination of ALPI and PU on the freshwater planarian Girardia tigrina. The exposure to both ALPI and PU revealed a sequential effect, i.e., a decrease in locomotor activity, while oxidative stress biomarkers (total glutathione, catalase, glutathione S-transferase, lipid peroxidation) and metabolic responses (cholinesterase activity, electron transport system, and lactate dehydrogenase) remained unaffected. Despite this fact, it was possible to observe that the range of physiological responses in exposed organisms varied, in particular in the cases of the electron transport system, cholinesterase activity, glutathione S-transferase, catalase, and levels of total glutathione and proteins, showing that the energetic costs for detoxification and antioxidant capacity might be causing a lesser amount of energy allocated for the planarian activity. By examining the physiological, behavioural, and ecological responses of planarians to these pollutants, insights can be gained into broader ecosystem-level effects and inform strategies for mitigating environmental risks associated with OPFRs and microplastic pollution in freshwater environments. [ABSTRACT FROM AUTHOR] |
