Impacto da poluição ambiental em manguezal brasileiro, bioacumulação de HPAs em Spartina alterniflora
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Data
2022-02-10
Autores
Sugauara, Lucy Elaine
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Universidade Estadual Paulista (Unesp)
Resumo
Os hidrocarbonetos policíclicos aromáticos (HPAs) são contaminantes historicamente conhecidos, apresentam propriedades carcinogênicas, mutagênicas e teratogênicas sendo amplamente distribuidos e encontrados como constituintes de misturas complexas em todos os compartimentos ambientais. São considerados, dentre a classe de hidrocarbonetos, os mais tóxicos existentes, razão da grande importância dos estudos acerca desta classe de compostos. A região da Baixada Santista é historicamente conhecida por seus altos níveis de contaminantes ambientais, possuindo no seu entorno Cubatão com uma das regiões industriais mais densas, o porto de Santos com seu intenso tráfego de navios de carga, diversos locais de armazenamento de produtos derivados de petróleo e grandes áreas com crescimento populacional desordenado como o Dique da Gilda, a maior comunidade de palafita do Brasil. Este estudo teve como objetivo geral avaliar o comportamento da espécie Spartina alterniflora, quanto ao acúmulo de HPAs em estuário da zona litorânea do estado de São Paulo. Para isso, foram validados métodos de extração de HPAs para análise cromatográfica (GC-MS e/ou HPLCFLU) de amostras de sedimento e de Spartina alterniflora, planta invasora conhecida por seu potencial biorremediador de contaminantes orgânicos e inorgânicos.Os métodos validados para análise de HPAs em sedimento e Spartina alterniflora, incluiram a extração por solvente em banho de ultrassom e análise por GC-MS, alcançando limites de quantificação de 15 a 20 ng g-1 . Houve correlação entre as concentrações encontradas na planta (parte aérea + raíz) e as concentrações encontradas no sedimento próximo a planta (R2 =0,842), indicando que esta espécie apresenta potencial de bioremediação para os HPAs. As concentrações de HPAs encontradas em Spartina alterniflora foram de 209±30 a 1581±133 ng g-1 e em sedimento, a máxima concentração encontrada foi de 66.451µg kg-1 , valor dez vezes inferior à maior concentração publicadas pela CETESB em 2001de 734.000 µg kg-1 (para o mesmo ponto incluído neste trabalho). Esta observação pode ser atribuída a alterações no parque industrial de Cubatão (modificação das políticas públicas, mudança de processos, etc), ocorridas nas duas décadas entre os períodos de amostragem: 2000 e 2017. Todas as amostras de sedimento mostraram fitotoxicidade (Lactuca sativa) e para o teste em organismo (Tiburella viscana) mais de 60% das amostras indicou toxicidade significativa. No entanto, sendo a Baixada Santista uma região historicamente bastante impactada, a toxicidade encontrada não pode ser correlacionada apenas com os HPAs. Foram calculadas as razões de diagnóstico (ratios), de acordo com diversas referências da literatura, sendo possível inferir que fontes pirogênicas apresentam maior contribuição para os HPAs presentes na região estudada. Utilizando os PCA foi possível agrupar as amostras com o somatório das concentrações de todos os HPAs sendo o fenantreno, antraceno, criseno, benzo(b)fluoranteno e indeno(1,2,3-cd)pireno as respostas mais significativas para este agrupamento.
Polycyclic aromatic hydrocarbons (PAHs) are historically known contaminants. They have carcinogenic, mutagenic and teratogenic properties, being widely spread and found as constituents of complex mixtures in all environmental areas. In the class of hydrocarbons, they are considered the most toxic, that being the reason for the great importance of the studies about this class of compounds. The region of Baixada Santista is historically known for its high levels of environmental contaminants, having in its surroundings: Cubatão, home of one of the densest industrial regions; the port of Santos with its intense traffic of cargo ships; several storage silos housing derivatives of oil; and large areas with population growing chaotically such as Gilda´s Dique, the largest stilt slum in Brazil. This study aimed to evaluate the behavior of the species Spartina alterniflora, focusing on the accumulation of PAHs in estuary areas in the coastal zone in Sao Paulo. In order to achieve this goal, methods of PAH extraction were validated for chromatographic analysis (GC/MS and/or HPLC/FLU) of sediment samples and Spartina alterniflora, an invasive plant known for its bioremediation potential of both organic and inorganic contaminants. The validated methods for PAHs analysis in sediment and Spartina alterniflora included solvent extraction in an ultrasound bath and GC-MS analysis, reaching quantification limits of 15 to 20 ng g-1 . A correlation between the concentrations found in the plant (shoot + root) and the concentrations found in the sediment near the plant (R2 =0.842) was identified, indicating that this species has potential for bioremediation for PAHs. The PAH concentrations found in Spartina alterniflora ranged from 209±30 to 1581±133 ng g-1 and in sediment, maximum concentration of 66,451 µg kg-1 . Both concentrations are lower than the concentrations published in a 2001 CETESB study, which reported maximum of 734,000 µg kg-1 for the same area included in this work. This observation can be attributed to changes in the industrial park of Cubatão (industries leaving the area, changes in processes, etc.), which occurred in the two decades between the sampling periods of 2000 and 2017. All sediment samples showed phytotoxicity (Lactuca sativa) and more than 60% of the organism (Tiburella viscana) test samples indicated significant toxicity. The Baixada Santista is a highly impacted region, however the toxicity found cannot be correlated with PAHs alone. The diagnostic ratios were calculated according to several references in the literature, making it possible to infer that pyrogenic sources present the greatest contribution to the PAHs detected source in the studied area. By using PCA, it was possible to group the samples with the sum of the concentrations of all PAHs, with phenanthrene, anthracene, chrysene, benzo(b)fluoranthene and indene(1,2,3-cd)pyrene being the most significant responses for this grouping.
Polycyclic aromatic hydrocarbons (PAHs) are historically known contaminants. They have carcinogenic, mutagenic and teratogenic properties, being widely spread and found as constituents of complex mixtures in all environmental areas. In the class of hydrocarbons, they are considered the most toxic, that being the reason for the great importance of the studies about this class of compounds. The region of Baixada Santista is historically known for its high levels of environmental contaminants, having in its surroundings: Cubatão, home of one of the densest industrial regions; the port of Santos with its intense traffic of cargo ships; several storage silos housing derivatives of oil; and large areas with population growing chaotically such as Gilda´s Dique, the largest stilt slum in Brazil. This study aimed to evaluate the behavior of the species Spartina alterniflora, focusing on the accumulation of PAHs in estuary areas in the coastal zone in Sao Paulo. In order to achieve this goal, methods of PAH extraction were validated for chromatographic analysis (GC/MS and/or HPLC/FLU) of sediment samples and Spartina alterniflora, an invasive plant known for its bioremediation potential of both organic and inorganic contaminants. The validated methods for PAHs analysis in sediment and Spartina alterniflora included solvent extraction in an ultrasound bath and GC-MS analysis, reaching quantification limits of 15 to 20 ng g-1 . A correlation between the concentrations found in the plant (shoot + root) and the concentrations found in the sediment near the plant (R2 =0.842) was identified, indicating that this species has potential for bioremediation for PAHs. The PAH concentrations found in Spartina alterniflora ranged from 209±30 to 1581±133 ng g-1 and in sediment, maximum concentration of 66,451 µg kg-1 . Both concentrations are lower than the concentrations published in a 2001 CETESB study, which reported maximum of 734,000 µg kg-1 for the same area included in this work. This observation can be attributed to changes in the industrial park of Cubatão (industries leaving the area, changes in processes, etc.), which occurred in the two decades between the sampling periods of 2000 and 2017. All sediment samples showed phytotoxicity (Lactuca sativa) and more than 60% of the organism (Tiburella viscana) test samples indicated significant toxicity. The Baixada Santista is a highly impacted region, however the toxicity found cannot be correlated with PAHs alone. The diagnostic ratios were calculated according to several references in the literature, making it possible to infer that pyrogenic sources present the greatest contribution to the PAHs detected source in the studied area. By using PCA, it was possible to group the samples with the sum of the concentrations of all PAHs, with phenanthrene, anthracene, chrysene, benzo(b)fluoranthene and indene(1,2,3-cd)pyrene being the most significant responses for this grouping.
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Palavras-chave
Sedimento marinho, Plantas de manguezal, Hidrocarbonetos policíclicos aromáticos, Planejamento experimental, Toxicologia ambiental