We aim to evaluate the quality of the Guanabara Bay sediments and the ecological changes due to the PETROBRAS crude oil leak in January 2000. Twenty-six sediment samples collected in July 2000 and in February 2001 wer...We aim to evaluate the quality of the Guanabara Bay sediments and the ecological changes due to the PETROBRAS crude oil leak in January 2000. Twenty-six sediment samples collected in July 2000 and in February 2001 were analyzed for pH, dissolved oxygen, and foraminiferal composition. In the northwest and central parts of the bay, low oxygen dissolved values are related to waste discharges with the dominance of Buliminella elegantissima. In winter, near Iguaçu River, the pH of the sediment is low, therefore highly acidic. The acidity is responsible for the foraminiferal low diversity limiting the occurrence of species with fragile tests. On the other hand, thicker tests of Elphidium spp. disappeared last, therefore increasing its relative dominance in winter. In summer, this is a barren zone. The explanation lies in the continuous dissolution of tests that culminated with the total disappearance of these microorganisms one year after the accident.展开更多
The world maritime transportation is suffering a large increase in recent years and as a result of this increased on global trade, there is a consequent increase in waterway transportation and demand for fossil fuels,...The world maritime transportation is suffering a large increase in recent years and as a result of this increased on global trade, there is a consequent increase in waterway transportation and demand for fossil fuels, resulting in emissions of air pollutants. Consequently, the impact of transport emissions on climate change was put on the list of priorities. It has a high fuel demand as a result of continuous use of main engines for propulsion, electricity and heat production. The highest exposure levels of air pollution are found in ports and near them because most of the world fleet is positioned in these areas. The port of Rio de Janeiro city, in the Southeast Brazilian coastal, is inserted in the Guanabara Bay (GB), where the breezes recirculate pollutants in Metropolitan Region of Rio de Janeiro (MRRJ). Therefore, the aim of this research was to use the Brazilian Regional Atmospheric Modeling System (BRAMS) to generate the wind fields in the MRRJ and to calculate the trajectories of pollutants emitted on GB related to the waterway transportation, using a 3D kinematic trajectories model. Results demonstrated that for the periods analysed, the Central and west areas in the coastal region of the Rio de Janeiro city were the local most affected in the summer. In winter the trajectories reached the cities of the Rio de Janeiro and Duque de Caxias. Both in summer and winter, the trajectories followed towards the South Atlantic Ocean in the morning. Conclusions about this study show the need of decision-making process for better management of waterway transportation sector, improving the harmful effects on air quality in cities located in coastal regions.展开更多
文摘We aim to evaluate the quality of the Guanabara Bay sediments and the ecological changes due to the PETROBRAS crude oil leak in January 2000. Twenty-six sediment samples collected in July 2000 and in February 2001 were analyzed for pH, dissolved oxygen, and foraminiferal composition. In the northwest and central parts of the bay, low oxygen dissolved values are related to waste discharges with the dominance of Buliminella elegantissima. In winter, near Iguaçu River, the pH of the sediment is low, therefore highly acidic. The acidity is responsible for the foraminiferal low diversity limiting the occurrence of species with fragile tests. On the other hand, thicker tests of Elphidium spp. disappeared last, therefore increasing its relative dominance in winter. In summer, this is a barren zone. The explanation lies in the continuous dissolution of tests that culminated with the total disappearance of these microorganisms one year after the accident.
文摘The world maritime transportation is suffering a large increase in recent years and as a result of this increased on global trade, there is a consequent increase in waterway transportation and demand for fossil fuels, resulting in emissions of air pollutants. Consequently, the impact of transport emissions on climate change was put on the list of priorities. It has a high fuel demand as a result of continuous use of main engines for propulsion, electricity and heat production. The highest exposure levels of air pollution are found in ports and near them because most of the world fleet is positioned in these areas. The port of Rio de Janeiro city, in the Southeast Brazilian coastal, is inserted in the Guanabara Bay (GB), where the breezes recirculate pollutants in Metropolitan Region of Rio de Janeiro (MRRJ). Therefore, the aim of this research was to use the Brazilian Regional Atmospheric Modeling System (BRAMS) to generate the wind fields in the MRRJ and to calculate the trajectories of pollutants emitted on GB related to the waterway transportation, using a 3D kinematic trajectories model. Results demonstrated that for the periods analysed, the Central and west areas in the coastal region of the Rio de Janeiro city were the local most affected in the summer. In winter the trajectories reached the cities of the Rio de Janeiro and Duque de Caxias. Both in summer and winter, the trajectories followed towards the South Atlantic Ocean in the morning. Conclusions about this study show the need of decision-making process for better management of waterway transportation sector, improving the harmful effects on air quality in cities located in coastal regions.
