Microplastic pollution in aquatic ecosystems has drawn attention not only because microplastics are likely to accumulate anywhere but also because they cause negative impacts both to aquatic biota and, indirectly, to public health, as a result of their presence. The understanding of the distribution and accumulation patterns of this “new contaminant” is fundamental for the calibration of environmental risk studies. However, research on its migration pattern and consequent distribution is still limited. The present study has focused on the peculiar physical characteristics of plastic microparticles and the response to environmental factors such as hydrodynamics and physical chemistry of water on the diffusion dynamics of these pollutant agents. Therefore, we examined information about the vertical abundance distribution, the composition, and the sizes of microplastics, along with the varied aquatic environments existing on Earth. This study provides valuable evidence for the accumulation trend of microplastics across the environment and the peculiar particle characteristics that dictate their distribution patterns. The present study concluded that detailed studies should be carried out in order to add information about the behavior of plastic microparticles in aquatic environments and thus subsidize the calibration of existing information, thus increasing its accuracy in understanding the diffusion patterns of these polluting agents.

The Santos Estuarine System (SES), located in southwest Brazil, presents strategic economic importance for the country due to the presence of the biggest Brazilian Port and for being one of the most industrialized areas. On the other hand, this environment is adversely impacted by industrial and dredging activities, which can cause environment pollutants enrichment and potential hazard compound bioavailability. In this context, Polycyclic Aromatic Hydrocarbons (PAH) were assessed in fifteen sampling stations distributed along the estuary. Polycyclic aromatic hydrocarbon (PAH) concentrations were analyzed in surface sediment samples and two bivalve species’ tissues (Crassostrea rhizophorae and Perna Perna). In addition, water column salinity, sediment organic matter, and grain size were analyzed to check their influence on the contaminant accumulation. Total PAH sediment concentrations ranged between N.D. and 1711.79 ng g-1 dry weight (d.w.). Bivalve hydrocarbon levels varied between 88.38 and 988.76 ng g-1 (d.w.). The calculated PAH ratios revealed that the PAH compounds found in the studied area has both petrogenic and pyrolytic origins. A comparison of the PAH concentrations found in this study with those listed in the sediment quality guidelines (SQGs) indicated that adverse biological effects on the biota are eventually expected. Keywords: Polycyclic Aromatic Hydrocarbon; Contamination; Industrial Activities. O Sistema Estuarino de Santos (SES), localizado no sudoeste do Brasil, apresenta importância econômica estratégica para o país devido à presença do maior porto brasileiro e por ser uma das áreas mais industrializadas. Por outro lado, este ambiente é prejudicado pelas atividades industriais e de dragagem, que podem causar o aumento de poluentes ambientais e a biodisponibilidade de compostos potencialmente perigosos. Neste contexto, os hidrocarbonetos policíclicos aromáticos (HPA) foram avaliados em quinze estações de amostragem distribuídas ao longo do estuário. As concentrações de HPA foram analisadas em amostras de sedimentos superficiais e em tecidos de duas espécies bivalves (Crassostrea rhizophorae e Perna perna). Além disso, analisou-se a salinidade da coluna d'água, a matéria orgânica dos sedimentos e o tamanho dos grãos para verificar sua influência sobre o acúmulo de contaminantes. As concentrações totais de sedimentos HPA variaram entre N.D. e 1711,79 ng g-1 de peso seco (p.s.). Os níveis de hidrocarboneto bivalve variaram entre 88,38 e 988,76 ng g-1 (p.s.). As taxas de HPA calculadas revelaram que os compostos de HPA encontrados na área estudada têm origem petrogênica e pirolítica. Uma comparação das concentrações de HPA encontradas neste estudo com aquelas listadas nas diretrizes de qualidade de sedimentos (SQGs) indicou que os efeitos biológicos adversos sobre a biota são eventualmente esperados. Palavras-chave: Hidrocarbonetos Policíclicos Aromáticos; Contaminação; Atividades Iindustriais.

Changes in coastlines are considered one of the most dynamic processes in coastal environments. Therefore, the mapping of such variations has become important in the survey of coastal impacts. In the past years, remote sensing has been used in mapping the coastline. In this research, the coastline of Guanabara Bay, in Rio de Janeiro, Brazil, was mapped in the years of 1938, 1974, 1984, 1997, and 2015, by using geo-referencing software and existing cartographic documents. To map the changes, the bay was divided into four sections, in which maps were produced in graphical format, using ArcGIS, in scales 1:175.000 and 1:250.000. The research used satellite images from Landsat 1 Multispectral Scanner System (MSS), Landsat 5 Thematic Mapper (TM), and Landsat 8 Operational Land Imager (OLI), integrated under geographic information system database, for a visual analysis (qualitative), and statistical observation (quantitative) of orbital images. The data indicate more intense transformations between the years 1938 and 1974, with a total landing area of 15.220.000m². This area corresponds to 69.23% of the amount suppressed during the interval 1938-2015. As mudanças nas linhas costeiras são consideradas um dos processos mais dinâmicos em ambientes costeiros. Portanto, o mapeamento de tais variações tornou-se importante no levantamento dos impactos costeiros. Nos últimos anos, o sensoriamento remoto tem sido utilizado no mapeamento da linha de costa. Nesta pesquisa, o litoral da Baía de Guanabara, localizada no estado do Rio de Janeiro, Brasil, foi mapeado nos anos de 1938, 1974, 1984, 1997 e 2015, utilizando um software de georreferenciamento e documentos cartográficos. Para mapear as mudanças, a baía foi dividida em quatro seções, para as quais foram produzidos mapas em formato gráfico, usando ArcGIS, em escalas de 1:175.000 e 1:250.000. A pesquisa utilizou imagens de satélite de Landsat 1 Multispectral Scanner System (MSS), Landsat 5 Thematic Mapper (TM) e Landsat 8 Operational Land Imager (OLI), integradas em base de dados de um sistema de informação geográfica, para uma análise visual (qualitativa) e observação estatística (quantitativa) de imagens orbitais. Os dados indicam transformações mais intensas entre os anos 1938 e 1974, com uma área total de desembarque de 15.220.000m2. Esta área corresponde a 69,23% da quantidade suprimida durante o intervalo entre 1938 e 2015.

During the last decades, the global quest for development allied with new technologies has antagonized hunger and income concentration, resulting in nutritional insecurity and social injustice. This panorama reinforces the spread of diseases, violence, and the consequent destruction of biological diversity through the unbridled use of its natural resources. Durante as últimas décadas, a procura global do desenvolvimento aliada às novas tecnologias antagonizam com a fome e a concentração de renda, resultando na insegurança nutricional e na injustiça social. Este quadro reforça o quadro de disseminação de doenças, a violência e consequente destruição da diversidade biológica através do uso desenfreado dos seus recursos naturais.

Mollusks are considered one of the main bioindicators of pollution in aquatic environments, however, they are also the basis of food for several communities around the world. In estuaries such as the one monitored in this study, Paranaguá Estuarine Complex, where salinity variation is a relevant point, the bioaccumulation of metals (Al, As, Mn, Ni, Cu, Zn and Cd) in Crassostrea gasar oysters was identified in 5 different locations. Additionally, human health risk indexes were calculated from the concentration of metals found in oysters. Oysters were collected from 5 sampling stations along Paranaguá Estuarine System, close to oyster producing communities, natural banks used for extraction and containing large human populations, with potential for high environmental pollution. The oysters (C. gasar) proved effective in the environmental monitoring of these pollutants and emphasized the need for constant monitoring of the estuary, especially regarding As and Zn.