Bioaccumulation of Total Mercury (THg) in Catfish (Siluriformes, Ariidae) with Different Sexual Maturity from Cananéia-Iguape Estuary, SP, Brazil.

In order to improve the knowledge of total mercury (THg) bioaccumulation in bioindicator species of sea catfish (Siluriformes, Ariidae) and taking into account the relatively recent approach with respect to estuarine fish on the Brazilian coast, 65 individuals were caught in the northern and southern regions of the Cananeia estuary to determine the concentration of the THg in muscles, gills, gonads and kidney of the Cathorops spixii and Genidens genidens specimens. The difference in the THg accumulation associated to the maturity of the catfish reflects a differential metabolism regarding THg bioaccumulation in adults (males and females) and juveniles. These observations reinforce the importance of considering the maturity of the individual in order to understand the bioaccumulation and metabolism of fish under different environmental stress and conditions. Furthermore, abiotic conditions such as salinity should be evaluated in association with metabolic/biological conditions of the fish's bioindicators, especially in environments with large natural or anthropogenic transition gradients.

Correction to: Bioaccumulation of Total Mercury (THg) in Catfish (Siluriformes, Ariidae) with Different Sexual Maturity from Cananéia-Iguape Estuary, SP, Brazil.

The original version of the article contained a mistake in the unit values. In the fourth paragraph of "Materials and Methods" section, the fourth sentence should read as: The obtained detection and quantification limits were 0.408 ng g-1 and 3.619 ng g-1, respectively, with circa 90% recovery compared with DORM-4, showing high precision and accuracy of the THg determination.

Effects of harbor activities on sediment quality in a semi-arid region in Brazil.

Tropical marine environments are rich in biodiversity and the presence of harbor activities in these areas can harm the coastal ecosystems. In this study, we assessed sediment quality of two harbors from a tropical region in Brazil by applying multiple lines-of-evidence approach. This approach included the integration of results on: (1) grain size, organic matter, organic carbon, nitrogen, phosphorus, trace metals, polycyclic aromatic hydrocarbons, linear alkylbenzenes, and tributyltin; (2) acute toxicity of whole sediments and chronic toxicity of liquid phases; and (3) benthic community descriptors. Our results revealed that the main contaminants detected in sediments from Mucuripe and Pecém Harbors were chromium, copper, nitrogen, zinc, and tributyltin. These toxicants arise from typical harbor activities. However, the changes in benthic composition and structure appear to depend on a combination of physical impacts, such as the deposition of fine sediments and the toxic potential of contaminants, especially in Mucuripe. Thus, apart from toxicants physical processes are important in describing risks. This information may assist in management and conservation of marine coastal areas.

An environmental forensic approach for tropical estuaries based on metal bioaccumulation in tissues of Callinectes danae.

The blue crab Callinectes danae is distributed throughout the Atlantic coast and this study aimed to evaluate a environmental forensics approach that could be applied at tropical estuarine systems where this species is distributed, based on the metal concentrations in its tissues. For this purpose, blue crab samples were collected in 9 sites (distributed in 3 areas) along the Santos Estuarine System, state of São Paulo, Brazil. The concentrations of Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn were determined in gills, hepatopancreas and muscle tissues. Sediment samples were collected and analyzed in these same sites. A data distribution pattern was identified during both sampling periods (August and December 2011). In order to validate this model, a new sampling campaign was performed in March 2013 at the Santos Estuarine System and also at Ilha Grande (state of Rio de Janeiro). These data were added to the previous database (composed of the August and December 2011 samples) and a discriminant analysis was applied. The results confirmed an environmental fingerprint for the Santos Estuarine System.

A preliminary assessment of metal bioaccumulation in the blue crab, Callinectes danae S., from the Sao Vicente Channel, Sao Paulo State, Brazil.

The concentrations of metals in tissues of Callinectes danae were evaluated, aiming to determine the bioaccumulation process of this species. Gills presented the highest mean concentrations for most metals, except for Hg (

Assessment of metal concentrations in muscles of the blue crab, Callinectes danae S., from the Santos Estuarine System.

This study determined the concentrations of eleven metals in the blue crab, Callinectes danae, from nine sites in the Santos Estuarine System of Sao Paulo State, Brazil. The results were compared to guidelines established in the United States, Europe and Brazil for the safety of human consumers. Muscles of blue crabs were removed by dissection and concentrations of Al, Cd, Co, Cr, Cu, Fe, Hg, Mn Ni, Pb and Zn were determined. In general, the concentrations of metals were low, and the crabs were regarded as safe for human consumption. Crabs from a single site (site 4) exceeded the guidelines established by the United States and Europe, but not Brazil, for Pb, with a mean tissue concentration of 1.725 µg g(-1). With the exception of Al, Fe and Ni, significant differences were noted between sites in the concentrations of each metal in crab tissue.

In vitro biocompatibility of new bioactive lithia-silica glass-ceramics.

Glass-ceramics based on the Li2O-SiO2 system have been extensively used as restorative dental materials due to their excellent chemical durability, aesthetics, inertness in the buccal environment, and high fracture strength; but they are not bioactive. On the other hand, all known bioactive glasses show ability to bond to bone, teeth and cartilage coupled to osteoconduction and osteoinduction, but their fracture strength and toughness are rather low. The aim of this study is to develop and evaluate the in vitro biocompatibility of a new type of (bioactive and strong) lithia-silica glass-ceramic. For these purposes, two types of glass-ceramics based on a multicomponent lithia-silica system were studied: lithium metasilicate (LM) and lithium disilicate (LD). The in vitro bioactivity study was conducted in a SBF solution, before and after different times of immersion; the new materials were analyzed by XRD, FTIR, and SEM. Some samples were subjected to in vitro biodegradation tests to quantify the release of lithium and the weight loss. Cytotoxicity, adhesion, and cell proliferation on different samples were examined by using the Methyl Tetrazolium salt (MTS) and Alizarin Red. For ~40 vol% crystallinity, lithium metasilicate was detected as the major phase, whereas for ~80 vol% crystallinity, lithium disilicate was the major phase. The LD proved to be strong (3p-bending strength of 233 ±â€¯12 MPa) and bioactive after 14 days of immersion in SBF. In terms of lithium ion release, the LD was outside the toxic range (>8.3 ppm). The LM and LD are not cytotoxic. The LD shows the best cellular adhesion and proliferation, leading to the formation of a mineralized matrix after 21 days. These results clearly suggest that the new LD brand is strong and highly biocompatible and warrants further study.

Contamination of port zone sediments by metals from Large Marine Ecosystems of Brazil.

Sediment contamination by metals poses risks to coastal ecosystems and is considered to be problematic to dredging operations. In Brazil, there are differences in sedimentology along the Large Marine Ecosystems in relation to the metal distributions. We aimed to assess the extent of Al, Fe, Hg, Cd, Cr, Cu, Ni, Pb and Zn contamination in sediments from port zones in northeast (Mucuripe and Pecém) and southeast (Santos) Brazil through geochemical analyses and sediment quality ratings. The metal concentrations found in these port zones were higher than those observed in the continental shelf or the background values in both regions. In the northeast, metals were associated with carbonate, while in Santos, they were associated with mud. Geochemical analyses showed enrichments in Hg, Cd, Cu, Ni and Zn, and a simple application of international sediment quality guidelines failed to predict their impacts, whereas the use of site-specific values that were derived by geochemical and ecotoxicological approaches seemed to be more appropriate in the management of the dredged sediments.