Avaliação de risco ecológico da Lagoa de Jacarepaguá – RJ: presença de aditivos plásticos

Abstract

The Jacarepaguá Lagoon has been suffering from the release of effluents and the irregular disposal of solid waste due to the accelerated urban growth of the surrounding areas without the presence of adequate infrastructure for basic sanitation. Both effluents and solid waste release micropollutants into the lagoon, wich act as endocrine disruptors, in addition to increasing the organic matter and the concentration of nutrients. The objective of this work was to develop an Ecological Risk Assessment (ERA) based on four lines of evidence (LoE): Water Quality (WA), which evaluated physical-chemical parameters; Chemistry (Chem), which evaluated the concentration of plastic additives in water samples; Ecotoxicological (Ecotox), which evaluated the toxic effects of environmental samples on test organisms; and Ecological (Eco), which evaluated the richness, abundance, and evenness of the phytoplankton community in the lagoon. Six campaigns were carried out between 2019 and 2020 at five points in the Jacarepaguá Lagoon and at one in the Camorim Dam, used as a reference area. The environmental risk was calculated from the integration of the risks obtained in the four lines of evidence evaluated. The lagoon points presented high risk (0.5-0.75) to very high risk (0.75-1.0) for LoE WQ, Chem and Eco. Most points in the lagoon presented high (0.5-0.75) to very high risk (0.75-1.0) for LoE Ecotox. In the risk integration, all points were considered high risk (0.5-0.75) to very high risk (0.75-1.0), based on the total average of the integrated risk values for each point in the lagoon. Therefore, it is concluded form these results that the lagoon is a eutrophic ecosystem in an advanced stage due to the release of untreated or partially treated effluents into rivers and the irregular disposal of solid waste. It is expected that the study can be used in the future to eliminate pollution sources and to recover the Jacarepaguá Lagoon.