Results from a 15-year study on hydrocarbon concentrations in water and sediment from Admiralty Bay, King George Island, Antarctica

Admiralty Bay on the King George Island hosts the Brazilian, Polish and Peruvian research stations as well as the American and Ecuadorian field stations. Human activities in this region require the use of fossil fuels as an energy source, thereby placing the region at risk of hydrocarbon contamination. Hydrocarbon monitoring was conducted on water and sediment samples from the bay over 15 years. Fluorescence spectroscopy was used for the analysis of total polycyclic aromatic hydrocarbons (PAHs) in seawater samples and gas chromatography with flame ionization and/or mass spectrometric detection was used to analyse individual n-alkanes and PAHs in sediment samples. The results revealed that most sites contaminated by these Compounds are around the Brazilian and Polish research stations due to the intense human activities, mainly during the summer. Moreover, the sediments revealed the presence of hydrocarbons from different sources, suggesting a mixture of the direct input of oil or derivatives and derived from hydrocarbon combustion. A decrease in PAH concentrations occurred following improvement of the sewage treatment facilities at the Brazilian research station, indicating that the contribution from human waste may be significant.

Accidents by external causes in adolescents: care in sentinel urgency and emergency services in the Brazilian State Capitals-2009

Adolescents are seeking new references and experiences, which may involve attitudes of risk and exposure to accidents and violence from external causes. These events constitute a serious Public Health problem. The scope of this study was to analyze the occurrence of accidents by external causes in adolescents from 10 to 19 years of age attended at sentinel urgency and emergency services in Brazil. Data from the 2009 Surveillance System for Violence and Accidents (VIVA 2009) was analyzed in 74 emergency units in 23 state capitals and the Federal District. The findings revealed that 6,434 adolescents (89.8%) were victims of accidents and 730 (10.2 %) were victims of violence. The main causes of the accidents were falls and traffic accidents, and assaults were predominant in violence. For both accidents and violence, non-white male adolescents were predominant and the events occurred most frequently on the public highways. A marked increase was detected, with hospitalization of victims of violence between 15 and 19 years of age. Understanding the epidemiological reality of external causes among adolescents represents an important tool for health prevention and promotion policies and the culture of peace seeking to reduce morbidity and mortality.

Reducing Water and Chloride Penetration Through Silicate Treatments for Concrete as a Mean to Control Corrosion Kinetics

There are currently many types of protective materials for reinforced concrete structures and the influence of these materials in the chloride diffusion coefficient and water penetration still needs more research. The aim of this work is to analyze the contributions regarding the typical three surface concrete protection systems (coatings, linings and pore blockers) and discusses the results of three pore blockers (sodium silicate) tested in this work. To this end, certain tests were used: one involving permeability mechanism (low pressure-immersion absorption), one involving capillary water absorption, and the last, a migration test used to estimate the effective chloride diffusion coefficient in saturated condition. Results indicated reduction in chloride diffusion coefficients and capillary water absorption, therefore, restrictions to water penetration from external environmental. As a consequence, a reduction of the corrosion kinetics and a control of the chloride ingress are expected.