Temporal evolution of the contamionation in the southern area of patos lagoon estuary,RS, Brazil

• Autor(a) principal: Wallner-Kersanach, Mônica
• Data de Publicação: 2015
• Outros Autores: Mirlean, Nicolai, Baumgarten, Maria da Graça Zepka, Costa, Luiza Dy Fonseca, Baisch, Paulo Roberto Martins
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da FURG (RI FURG)
• Texto Completo: http://repositorio.furg.br/handle/1/5973
• topic: Contamination; Nutrients; Trace metals; Estuary; Environmental managemen; Contaminação; Metais traço; Nutrientes; Estuário; Gestão ambiental

The southern area of the Patos Lagoon estuary has been subjected to intense industrial and port-related activities which have not only caused meaningful changes in the landscape but also degraded aquatic resources by contaminating them with dissolved nutrients and trace metals in the last decades. This study aims at compiling data on the development that has happened in the urban and industrial occupation in Rio Grande, a city located in the south of Rio Grande do Sul, RS, Brazil, by relating it to the main results of contamination indicators in the estuarine environment regarding water, sediment, soil and atmosphere. Bibliographic data have shown an increase in domestic effluents around the city in the 1980’s, mainly in more sheltered areas, such as the Saco da Mangueira, where cyanobacteria eutrophication has often occurred because of the high concentration of nutrients. The content of trace metals in the water of channel areas of the estuary was always lower than the maximum limit established by Brazilian quality criteria. However, the sediment showed higher concentrations of some trace metals (e.g. copper, lead, nickel, vanadium and zinc), the metalloid As and Hg than the maximum concentrations established by the legislation, mainly in several places around urban, industrial and port areas. The labile fraction (or potentially bioavailable) in the water and in the sediment showed that trace metals have provided significant contributions to sheltered areas, such as marinas, but have exceeded in shipyards. Trace metals in the urban soil and man-made ground of the city indicated that there were anthropogenic contributions, mainly by mercury. Anomalies in the content of lead found in the atmospheric particulate matter and acid rain were also reported. Therefore, more severe environmental policies, effective control, industrial wastewater treatment and control of atmospheric emissions must be carried out in order to maintain environmental quality and public health. The city authorities in Rio Grande need to implement the existing integrated estuary management program in a proper and practical way, involving stakeholders and local governments.