Interações e impactos de distintos microplásticos sobre microalgas e macroinvertebrados aquáticos
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Data
2022-12-02
Autores
Borges, Bárbara Rani [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A poluição plástica é hoje ubíqua e permeia em praticamente todos os sistemas aquáticos, desde águas continentais, áreas costeiras, oceanos até regiões remotas e polares. Após o seu descarte e por diversas vias, os plásticos acabam chegando aos corpos d'água, onde sofrem exposição a condições ambientais, bióticas e abióticas, capazes de induzir a degradação e fragmentação dos plásticos em pedaços menores. Microplásticos (MP) são partículas antropogênicas (< 5 mm) e são hoje considerados os detritos mais difundidos nos ambientes aquáticos. Os ecossistemas de água doce são recursos especialmente suscetíveis a variações de ordem da qualidade ambiental e, a falta de dados referentes aos impactos causados por MP, exacerba a vulnerabilidade deste ambiente. Considerando este cenário, e dados recentes que demonstram que a crescente entrada de MPs no ambiente aquático pode provocar graves consequência para biota, o presente trabalho teve como objetivo a realização de uma série de ensaios toxicológicos com MP de características variadas e organismos de diferentes grupos de grande relevância para esses ecossistemas: microalgas das espécies Chlorella vulgaris e Raphidocelis subcaptata, e consumidores primários, representados por Chironomus sancticaroli, Daphnia similis, Hyalella azteca, Gmelinoides fasciatus e Gammarus lacustris. Os ensaios foram conduzidos com MP primários e secundários, com diâmetros de até 100 μm e concentrações variadas. Foram avaliadas respostas biológicas diferentes, de acordo com cada espécie, no geral os endpoints analisados foram: taxa de crescimento, atividade fotossintética, clorofila a, mortalidade, ingestão, egestão, estresse oxidativo, alterações comportamentais e biofragmentação de microplásticos pelos organismos. Os resultados mostraram que a ecotoxicidade de MP varia de acordo com as características físicas e químicas das partículas (tamanho, forma, concentração, tipo e tempo de exposição) e dos organismos interagentes, sendo que todos os organismos apresentaram algum efeito tóxico durante e após os períodos de exposição. Foram obtidos resultados diversos e inéditos que contribuem significativamente para o avanço do conhecimento na área. Pela primeira vez, foram registradas alterações à nível molecular nas espécies testadas de díptera e anfípoda após exposição sob condições ambientalmente relevantes e a biofragmentação de MP por D. similis e por H. azteca. Esses resultados reforçam a hipótese de que MP podem induzir respostas fisiológicas nas condições em que são encontrados atualmente, evidenciando os perigos a longo prazo. Futuros estudos poderão se beneficiar de tais desfechos abordados para estabelecer o padrão de distribuição de MP no ambiente e os riscos ecológicos atribuídos a esses eventos.
Plastic pollution is now ubiquitous and permeates virtually all aquatic systems, from inland waters, coastal areas, oceans to remote and polar regions. After its disposal and through various ways, the plastics end up reaching water bodies, where they are exposed to environmental, biotic and abiotic conditions, capable of inducing the degradation and fragmentation of plastics into smaller pieces. Microplastics are anthropogenic particles (< 5 mm) and are now considered the most widespread debris in aquatic environments. Freshwater ecosystems are resources especially susceptible to variations in environmental quality, and the lack of data on the impacts caused by plastic microparticles exacerbates the vulnerability of this environment. Considering this scenario, and recent data that demonstrate that the increasing entry of microplastics into the aquatic environment can cause serious consequences for biota, the present work aimed to carry out a series of toxicological tests with microplastics of varied characteristics and organisms from different groups of organisms. great relevance for these ecosystems: microalgae of the species Chlorella vulgaris and Raphidocelis subcapitata, and primary consumers, represented by Chironomus sancticaroli, Daphnia similis, Hyalella azteca, Gmelinoides fasciatus and Gammarus lacustris. Assays were conducted with primary and secondary microplastics, with sizes up to 100 μm and varying concentrations. Different biological responses were evaluated, according to each species, in general the endpoints analyzed were: growth rate, photosynthetic activity, chlorophyll a, mortality, ingestion, egestion, oxidative stress, behavioral changes and microplastic biofragmentation by organisms. The results showed that the toxicity of microplastics varies according to the physical and chemical characteristics of the particles (size, shape, concentration, type and exposure time) and of the interacting organisms, with all organisms having some toxic effect during and after the exposure periods. Diverse and unpublished results were obtained that contribute significantly to the advancement of knowledge in the area. For the first time, changes were recorded at the molecular level in the diptera and amphipod species tested after exposure under environmentally relevant conditions and PM biofragmentation by D. similis and by H. azteca. These results reinforce the hypothesis that PM can induce physiological responses in the conditions in which they are currently found, highlighting the long-term dangers. Future studies may benefit from such addressed outcomes to establish the pattern of PM distribution in the environment and the ecological risks attributed to these events.
Plastic pollution is now ubiquitous and permeates virtually all aquatic systems, from inland waters, coastal areas, oceans to remote and polar regions. After its disposal and through various ways, the plastics end up reaching water bodies, where they are exposed to environmental, biotic and abiotic conditions, capable of inducing the degradation and fragmentation of plastics into smaller pieces. Microplastics are anthropogenic particles (< 5 mm) and are now considered the most widespread debris in aquatic environments. Freshwater ecosystems are resources especially susceptible to variations in environmental quality, and the lack of data on the impacts caused by plastic microparticles exacerbates the vulnerability of this environment. Considering this scenario, and recent data that demonstrate that the increasing entry of microplastics into the aquatic environment can cause serious consequences for biota, the present work aimed to carry out a series of toxicological tests with microplastics of varied characteristics and organisms from different groups of organisms. great relevance for these ecosystems: microalgae of the species Chlorella vulgaris and Raphidocelis subcapitata, and primary consumers, represented by Chironomus sancticaroli, Daphnia similis, Hyalella azteca, Gmelinoides fasciatus and Gammarus lacustris. Assays were conducted with primary and secondary microplastics, with sizes up to 100 μm and varying concentrations. Different biological responses were evaluated, according to each species, in general the endpoints analyzed were: growth rate, photosynthetic activity, chlorophyll a, mortality, ingestion, egestion, oxidative stress, behavioral changes and microplastic biofragmentation by organisms. The results showed that the toxicity of microplastics varies according to the physical and chemical characteristics of the particles (size, shape, concentration, type and exposure time) and of the interacting organisms, with all organisms having some toxic effect during and after the exposure periods. Diverse and unpublished results were obtained that contribute significantly to the advancement of knowledge in the area. For the first time, changes were recorded at the molecular level in the diptera and amphipod species tested after exposure under environmentally relevant conditions and PM biofragmentation by D. similis and by H. azteca. These results reinforce the hypothesis that PM can induce physiological responses in the conditions in which they are currently found, highlighting the long-term dangers. Future studies may benefit from such addressed outcomes to establish the pattern of PM distribution in the environment and the ecological risks attributed to these events.
Descrição
Palavras-chave
Ecossistemas aquáticos, Toxicologia ambiental, Ecologia aplicada, Contaminantes emergentes na água, Microalgas, Diptera, Cladocera, Ecologia de água doce, Plásticos, Environmental toxicology, Emerging contaminants in water, Applied ecology, Freshwater ecology, Microalgae