Heavy metal inputs evolution to an urban hypertrophic coastal lagoon, Rodrigo De Freitas Lagoon, Rio De Janeiro, Brazil

Abstract

This work discusses the temporal variation of metal concentrations in a hypertrophic coastal lagoon located in the metropolitan area of Rio de Janeiro (Brazil). The lagoon watershed includes one of the mostly densely urbanized areas of the city but without industrial activities. Six sediment cores were collected in the lagoon between May and July 2003 and analyzed for the concentration of metals (Fe, Al, Mn, Zn, Pb, Cu, Cr, and Ni). Typical sedimentation rate was calculated as being 0.75 cm year( - 1) and was uniform for at least the past 70 years. Therefore, the alterations in the dynamics of the lagoon caused by changes in its watershed were clearly indicated in sediment cores. The construction of an artificial canal to the sea and the increasing urbanization and soil use changes were the major factors affecting metal accumulation in the lagoon sediments. Metals typical of anthropogenic urban sources (Pb, Zn, and Cu) showed increasing loads following urbanization.

Seagrass losses concerns: does sediment metal pollution matter?

“…This evidenced an association of trace metals with reactive Fe and Mn, without significant correlations with AVS, indicating that reactive Mn and Fe compounds are main geochemical carriers. Metal contaminant associations with Fe and Mn are frequently observed in coastal sediments, as reported for other parts of Rodrigo de Freitas Lagoon (Loureiro et al 2009). The correlations between trace metals can indicate similar geochemical behavior and metal source similarity, as previously found for Cu, Pb and Zn that are mostly affected by urban effluents inputs to Rodrigo de Freitas Lagoon (Loureiro et al 2009).…”

“…Details on this eutrophicated system contamination history are available elsewhere (Lacerda & Gonçalves 2001, Loureiro et al 2009). At least since nearly 2008, the government management policy to improve environmental and esthetical quality of the lagoon included the periodical removal of seagrass beds from its margins.…”

“…At least since nearly 2008, the government management policy to improve environmental and esthetical quality of the lagoon included the periodical removal of seagrass beds from its margins. We discuss here, based on preliminary analysis of seagrass bed sediments, the potential effects of the colonization by R. maritima on the sediment capacity to trap trace metal contaminants, such as Cu, Pb and Zn and possible implications of seagrass removal on this trapping (Loureiro et al 2009).…”

Influence of Salinity on the Toxicity of Dredged Sediments from Estuarine Rodrigo de Freitas Lagoon and Guanabara Bay (RJ): Toxic Effects On Earthworms

“…1 Introdução O despejo indiscriminado e sem pré-tratamento adequado de rejeitos industriais e de esgoto doméstico em sistemas aquáticos costeiros do Estado do Rio de Janeiro tem provocado a contaminação, eutrofização e assoreamento destes ambientes (Pereira et al, 2007;Loureiro et al, 2009;Araújo et al, 2017). Metais, hidrocarbonetos de petróleo, fármacos, hormônios, agroquímicos, dentre outras substâncias tóxicas, comumente ocorrem em amostras de água e de sedimentos destes ambientes (Stumpf et al, 1999;Stefens et al, 2007).…”

“…Além disso, a dragagem é fundamental à viabilização de atividades de navegação (sobretudo em zonas portuárias), prática de esportes aquáticos e de pesca segura para consumo humano. No caso do Estado do Rio de Janeiro, há necessidade de dragagem de setores diversos da Baía de Guanabara, Baía de Sepetiba, sistemas fluviais e lagunares de Jacarepaguá e da Barra da Tijuca, canais fluviais da baixada fluminense, Lagoa Rodrigo de Freitas e sistemas lagunares da Região dos Lagos (Almeida et al, 2001;Loureiro et al, 2009;Cesar et al, 2014;Silveira et al, 2017) A disposição terrestre destes sedimentos dragados é relativamente comum no Estado do Rio de Janeiro (Almeida et al, 2001;Cesar et al, 2014;Silveira et al, 2017). Diversos autores sugerem que metais e outras substâncias tóxicas têm potencial de causar efeitos nocivos à saúde da fauna edáfica (Neuhauser et al, 1985;Sivakumar, 2015).…”