Dinâmica e efeitos ecotoxicológicos de desreguladores endócrinos em ambientes estuarinos

Abstract

Endocrine disruptors (EDs) are compounds capable of causing adverse effects on exposed organisms, even at trace concentrations. These pollutants exhibit various transport and accumulation mechanisms, being widely distributed across different environmental compartments, with estuarine sediments standing out as a critical reservoir. These sediments, often impacted by pollution from domestic sewage discharges, play a significant role in the dynamics of environmental contamination. However, the presence of EDs in sediments and the impacts of this contamination on environmental dynamics and the trophic chain in estuarine environments remain underexplored. This study aims to evaluate the bioavailability, adsorption/desorption processes, and effects of these contaminants in estuarine sediments. The research encompasses the generation of data from ecotoxicological assays, chromatographic analyses, estrogenic potential evaluations, and the physicochemical characterization of estuarine sediments collected from three sites in Brazil. Scenarios of potential ecotoxicological effects on organisms directly and indirectly exposed to these contaminants in estuarine environments were assessed. The results indicated that organic matter content and the influence of saline waters are key factors affecting the bioavailability of EDs and the quantification of their effects through in vitro and in vivo assays. Among the estuaries analyzed, five water and sediment sampling points demonstrated estrogenic potential, with three of these points also exhibiting estrogenic activity in suspended particulate matter. The in vitro Yeast Estrogen Screen (YES) assay proved effective for monitoring different environmental matrices regarding the presence of estrogenic compounds. In contrast, traditional ecotoxicological assays based on the analysis of elutriates and interstitial water were insufficient to fully understand the effects of these contaminants on aquatic organisms. Thus, it is necessary to optimize analytical methodologies that more accurately reflect the environmental dynamics of contamination and their effects on aquatic organisms indirectly exposed to contaminated areas. This approach will enable a more robust assessment of ecological risks, contributing to the development of effective regulatory and mitigation strategies.