As relações de organismos bentônicos bioindicadores com a poluição por metais e metaloides em represas do sistema Cantareira, São Paulo
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Data
2016-05-12
Autores
Beghelli, Frederico Guilherme de Souza [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Vivemos atualmente, um cenário de crise hídrica mundial. Tal crise inclui tanto aspectos quantitativos quanto qualitativos ameaçando a segurança hídrica das sociedades humanas e os ecossistemas do planeta Terra. No Brasil, a região hidrográfica do Paraná destaca-se como região com maior densidade populacional, desenvolvimento econômico e industrial do país sendo, portanto, a região com maior demanda pelo recurso. No Estado de São Paulo desenha-se uma situação de crise hídrica agravada em ambos os aspectos. Do ponto de vista qualitativo, a Região Metropolitana de São Paulo destaca-se como aquela cujos mananciais encontram-se em situação mais impactada. O Sistema Cantareira, composto por um conjunto de cinco reservatórios é um dos principais sistemas fornecedores de água para esta região de intensas demandas e geradora de grandes impactos ambientais. A poluição de ambientes aquáticos por metais e metaloides é um problema mundial e frequentemente associado aos impactos gerados por regiões urbanas e industrializadas. Um agravante deste tipo de poluição, é o fato de os metais e metaloides não serem metabolizados pela biota, de forma que estes elementos tendem a se acumular, especialmente nos sedimentos, ao longo do tempo, com possibilidade de poluição das águas e dos organismos que habitam os ecossistemas aquáticos. Neste estudo, foram levantados dados referentes a qualidade da água e dos sedimentos de três reservatórios pertencentes ao Sistema Cantareira (Jaguari e Jacareí sendo consideradas como um único reservatório). Posteriormente, foram realizados estudos da fauna de macroinvertebrados bentônicos destes locais e experimentos com o intuito de se verificarem as respostas destes organismos à poluição das águas e sedimentos por metais e metaloides. Os resultados obtidos, indicaram poluição das águas e dos sedimentos destes reservatórios por diferentes elementos químicos (Al, Cd, Cr, Cu, Ni, Pb e Zn). Foi verificado, com dados de campo e testes estatísticos, que alterações morfológicas em larvas de Chironomidae variavam em função do aumento das concentrações de cobre nos sedimentos e que estas concentrações eram suficientes para provocar bioacumulação nos organismos. Posteriormente, demonstrou-se com um experimento in situ, que os sedimentos do reservatório Paiva Castro estavam poluídos e foram capazes de induzir efeitos letais e subletais em larvas de Chironomus sancticaroli. A realização de um experimento similar em laboratório e com sedimentos formulados resultou na conclusão de que as concentrações de cobre nos sedimentos, de fato induzem efeitos tóxicos sobre as larvas desta espécie, incluindo o aumento de “danos totais” (alterações morfológicas ou morte) a concentrações próximas às registradas no Paiva Castro. Por fim, utilizando-se modelos estatísticos e o conjunto de dados obtidos em campo, foi possível demonstrar os efeitos da toxicidade de diferentes metais (Al, Cr e Cu) em nível de comunidade, fornecendo-se as bases para o desenvolvimento de um índice da comunidade de macroinvertebrados bentônicos específico para poluição por metais para a região de estudo.
A global water crisis is in course. This crisis include quantitative and qualitative aspects and it threatens the water security of human societies and of the Earth’s ecosystems. In Brazil, the Paraná hydrographic region is the one with highest population density, economic and industrial development. As consequence, it is the hydrographic region in Brazil that demands highest amounts of water. São Paulo state is suffering the effects of the hydrological crisis. Qualitatively, the Metropolitan Region of São Paulo includes some of the most impaired aquatic environments. The Cantareira Complex is formed by five reservoirs. It is one of the main water suppliers of the region, which has high water demand and produces intensive environmental impairments. The pollution of aquatic environments by metals and metalloids is a worldwide problem and it is frequently related to the impairments generated in urban and industrialized regions. A problem related with this type of pollution is the fact that metals and metalloids are not metabolized by biota. As consequence, these chemicals have the tendency to accumulate through the time in the environment, especially in the sediments. Therefore, the pollution of the sediments can favor water pollution and the contamination of organisms living in aquatic ecosystems. In the present research, data referring to water and sediment quality from three reservoirs from Cantareira Complex (Jaguari and Jacareí were considered as a whole) were obtained. Posteriorly, the benthic macroinvertebrates fauna from those reservoirs were analyzed in order to verify the impacts of metal pollution over them. Experiments aiming to verify the responses of these organisms to sediment pollution by metals, especially copper were performed. The results points that water and sediments of the reservoirs analyzed here are polluted by metals and metalloids (Al, Cd, Cr, Cu, Ni, Pb and Zn). From field data and statistical analyses, it could be concluded that morphological alterations in Chironomidae larvae varied as a response to copper concentration in the sediments and that the copper concentrations were sufficiently high to cause bioaccumulation in the organisms. Posteriorly, it was demonstrated by an in situ assay that sediments from Paiva Castro were really contaminated and them induced lethal and sublethal effects on Chironomus sancticaroli larvae. A similar experiment performed in laboratory with spiked sediments leads to the conclusion that the copper in the sediments really can produce toxic effects on the larvae. Toxic effects included an increasing in “total damage” probabilities (morphological alteration or death) and they were recorded at concentrations similar to that recorded in the sediments from Paiva Castro reservoir. Another analysis included the use of statistical models to predict response of the organisms collected in the field to the toxicity of metals considering the community level. With this last approach, some basis to the development of a benthic macroinvertebrates community index to the assessment of pollution by metals (Al, Cr e Cu) in the region of Cantareira Complex was provided.
A global water crisis is in course. This crisis include quantitative and qualitative aspects and it threatens the water security of human societies and of the Earth’s ecosystems. In Brazil, the Paraná hydrographic region is the one with highest population density, economic and industrial development. As consequence, it is the hydrographic region in Brazil that demands highest amounts of water. São Paulo state is suffering the effects of the hydrological crisis. Qualitatively, the Metropolitan Region of São Paulo includes some of the most impaired aquatic environments. The Cantareira Complex is formed by five reservoirs. It is one of the main water suppliers of the region, which has high water demand and produces intensive environmental impairments. The pollution of aquatic environments by metals and metalloids is a worldwide problem and it is frequently related to the impairments generated in urban and industrialized regions. A problem related with this type of pollution is the fact that metals and metalloids are not metabolized by biota. As consequence, these chemicals have the tendency to accumulate through the time in the environment, especially in the sediments. Therefore, the pollution of the sediments can favor water pollution and the contamination of organisms living in aquatic ecosystems. In the present research, data referring to water and sediment quality from three reservoirs from Cantareira Complex (Jaguari and Jacareí were considered as a whole) were obtained. Posteriorly, the benthic macroinvertebrates fauna from those reservoirs were analyzed in order to verify the impacts of metal pollution over them. Experiments aiming to verify the responses of these organisms to sediment pollution by metals, especially copper were performed. The results points that water and sediments of the reservoirs analyzed here are polluted by metals and metalloids (Al, Cd, Cr, Cu, Ni, Pb and Zn). From field data and statistical analyses, it could be concluded that morphological alterations in Chironomidae larvae varied as a response to copper concentration in the sediments and that the copper concentrations were sufficiently high to cause bioaccumulation in the organisms. Posteriorly, it was demonstrated by an in situ assay that sediments from Paiva Castro were really contaminated and them induced lethal and sublethal effects on Chironomus sancticaroli larvae. A similar experiment performed in laboratory with spiked sediments leads to the conclusion that the copper in the sediments really can produce toxic effects on the larvae. Toxic effects included an increasing in “total damage” probabilities (morphological alteration or death) and they were recorded at concentrations similar to that recorded in the sediments from Paiva Castro reservoir. Another analysis included the use of statistical models to predict response of the organisms collected in the field to the toxicity of metals considering the community level. With this last approach, some basis to the development of a benthic macroinvertebrates community index to the assessment of pollution by metals (Al, Cr e Cu) in the region of Cantareira Complex was provided.
Descrição
Palavras-chave
Sistema Cantareira, Poluição, Metais, Cobre, Macroinvertebrados, Chironomus, Cantareira complex, Pollution, Metals, Macroinvertebrates