Mantle-to-shell CaCO<Subscript>3</Subscript> transfer during shell repair at different hydrostatic pressures in the deep-sea vent mussel <Emphasis Type="Italic">Bathymodiolus azoricus</Emphasis> (Bivalvia: Mytilidae)

Calcium carbonate transfer was experimentally examined in hydrothermal mussels Bathymodiolus azoricus, which were collected from 850 m depth at Menez Gwen hydrothermal vent site (31°31′W, 37°50′N) on the Mid Atlantic Ridge in May 2007. In each of four 10-day experiments, groups of mussels were maintained at atmospheric pressure or re-pressurised to depths relevant to their site of occurrence, i.e. 850 m depth at Menez Gwen, 1,750 m at Lucky Strike (31°31′W, 37°18′N) and 2,300 m at Rainbow (31°31′W, 36°13′N). The shells of experimental mussels were perforated and mantle tissue was fixed for light and TEM studies at days 7 and 10 following the injury. Simultaneously, haemocytes from the extrapallial fluid (EPF) at the site of induction were studied. At day 7 the response was most intense in the middle fold of the mantle margin and possibly proportional to hydrostatic pressure. At day 10 the epithelial cells on the mantle surface facing the body cavity produced copious organic secretions that avidly bound calcium. Haemocyte migration was noted within the mantle tissue, and the haemocytes at the mantle surface facing the shell had a Ca-positive granular content. Large haemocytes were detected in the EPF at the injury site, and some showed evidence of an immune reaction while others showed Ca-positive granular content. These results suggest that haemocytes are involved in shell repair in these deep-sea mussels just as in some freshwater and shallow marine molluscs.     

Assessing the influence of urban geometry on noise propagation by using the sky view factor

The impact of traffic noise can be prevented by suitable planning measures. This study analyses the relationship between urban geometry and traffic noise, recognizing that the arrangement of buildings and streets greatly influences urban noise. The study was carried out in Braga, a medium-sized Portuguese city, by selecting locations with different urban geometries. At each site, the equivalent continuous sound level was measured. Furthermore, the urban geometry was evaluated by using the sky view factor, a parameter which shows the degree of sky obstructed by buildings. Results show an inverse proportionality between noise and the sky view factor. The highest noise levels were found in areas with a low sky view factor. The results also indicate that the sky view factor is a parameter which can potentially be used in research on urban noise.     

Analysis of energy security and sustainability in future low carbon scenarios for Brazil

This study estimated a series of indicators to assess the energy security of supply and global and local environmental impacts under different mitigation scenarios through 2050 in Brazil, designed with the integrated optimization energy system model MESSAGE‐BRAZIL. The assessment of interactions between environmental impacts and energy security dimensions was complemented through the application of life cycle assessment (LCA) methodology. Overall results imply energy security establishes more synergies than trade‐offs in increasingly stringent mitigation scenarios, especially patent within the sustainability dimension, which increases energy security and provides additional benefits regarding climate change mitigation and air pollution emissions. It is still necessary to extend analysis to other energy sectors in addition to the power supply sector and to promote a better understanding of repercussions of energy scenario expansion in energy security.     

Health concerns of consuming cockles (Cerastoderma edule L.) from a low contaminated coastal system

Commercial and recreational harvesting of shellfish within the coastal systems is usually very extensive. Since these ecosystems are frequently subjected to contamination, namely from agricultural, urban and industrial activities, and shellfish generally display a high capacity to bioaccumulate metals, populations may be at risk in terms of toxic metal exposure as a consequence of the harvesting and ingestion of near shore coastal marine organisms. Shellfish is regularly tested for concentrations of metals and other contaminants by legal authorities for commercial purposes, but although health officials use total metal as standards of food safety, only a part of the metal accumulated in shellfish is available to be assimilated and to cause toxic effect. In order to elucidate these issues an investigation on cockles inhabiting the Aveiro estuary was conducted. Element levels in sediments and wild Cerastoderma edule from sampling areas with different levels of contamination were measured; total element burden of cockles was related to accessible fraction for assimilation (TAM); element concentrations in wild C. edule were compared to EFSA (European Food Safe Authorities), USFDA (United States Food and Drug Administration) and FSANZ (Food Standards Australia and New Zealand) maximum levels (MLs); and the amount of cockle flesh needed to be consumed to exceed provisional tolerable weekly intake (PTWI) was determined. The present work showed that although sediment metal and metalloid contamination in Aveiro estuary is low the concentration of elements in C. edule does not reflect the contamination of the sediment. Aluminium (Al) and mercury (Hg) were the less and nickel (Ni), lead (Pb), zinc (Zn) and cadmium (Cd) were the most bioaccumulated metals by cockles. Comparison of MLs from international organisations with the concentration of elements in C. edule showed that arsenic (As) and Pb exceeded standard levels. The ingestion of less than 1 kg for As and 1.5 kg for Pb of cockles would result in exceeding the PTWI threshold (0.015 and 0.025 mg kg?1 week?1 respectively) in any of the areas considered in the study. Cd and Al also appear to be limiting elements for human consumption. Indeed, consumption of more than 3.1 kg and 2.1 kg of whole cockle soft part from one of the study areas during a single week would lead to exceedance of the recommended PTWI value for Cd (0.007 mg kg?1 week?1) and Al (7 mg kg?1 week?1) respectively. The health concerns to humans from cockle consumption from Aveiro estuary are discussed.     

Bacterial stimulation of copper phytoaccumulation by bioaugmentation with rhizosphere bacteria

Copper contaminated areas pose environmental health risk to living organisms. Remediation processes are thus required for both crop production and industrial activities. This study employed bioaugmentation with copper resistant bacteria to improve phytoremediation of vineyard soils and copper mining waste contaminated with high copper concentrations. Oatmeal plant (Avena sativa L.) was used for copper phytoextraction. Three copper resistant bacterial isolates from oatmeal rhizosphere (Pseudomonas putida A1; Stenotrophomonas maltophilia A2 and Acinetobacter calcoaceticus A6) were used for the stimulation of copper phytoextraction. Two long-term copper contaminated vineyard soils (Mollisol and Inceptisol) and copper mining waste from Southern Brazil were evaluated. Oatmeal plants substantially extracted copper from vineyard soils and copper mining waste. As much as 1549 mg of Cu kg?1 dry mass was extracted from plants grown in Inceptisol soil. The vineyard Mollisol copper uptake (55 mg Cu kg?1 of dry mass) in the shoots was significantly improved upon inoculation of oatmeal plants with isolate A2 (128 mg of Cu kg?1 of shoot dry mass). Overall oatmeal plant biomass displayed higher potential of copper phytoextraction with inoculation of rhizosphere bacteria in vineyard soil to the extent that 404 and 327 g ha?1 of copper removal were respectively observed in vineyard Mollisol bioaugmented with isolate A2 (S. maltophilia) and isolate A6 (A. calcoaceticus). Results suggest potential application of bacterial stimulation of phytoaccumulation of copper for biological removal of copper from contaminated areas.     

Evaluation of an approach for the characterization of reactive and available pools of 20 potentially toxic elements in soils: part II--solid-solution partition relationships and ion activity in soil solutions

To assess environmental risks related to contaminants in soil it is essential to predict the available pool of inorganic contaminants at regional scales, accounting for differences between soils from variable geologic and climatic origins. An approach composed of a well-accepted soil extraction procedure (0.01 M CaCl(2)) and empirical Freundlich-type models in combination with mechanistically based models which to date have been used only in temperate regions was applied to 136 soils from a South European area and evaluated for its possible general use in risk assessment. Empirical models based on reactive element pools and soil properties (pH, organic carbon, clay, total Al, Fe and Mn) provided good estimations of available concentrations for a broad range of contaminants including As, Ba, Cd, Co, Cu, Hg, Mo, Ni, Pb, Sb, Se and Zn (r(2): 0.46-0.89). The variation of the pools of total Al in soils expressed the sorptive capacity of aluminosilicates and Al oxides at the surfaces and edges of clay minerals better than the actual variability of clay contents. The approach has led to recommendations for further research with particular emphasis on the impact of clay on the solubility of As and Sb, on the mechanisms controlling Cr and U availability and on differences in binding properties of soil organic matter from different climatic regions. This study showed that such approach may be included with a good degree of certainty for first step risk assessment procedures to identify potential risk areas for leaching and uptake of inorganic contaminants in different environmental settings.     

Experimental evidence for a significant contribution of cellulose to indoor aerosol mass concentration

An apartment bedroom located in a residential area of Aveiro (Portugal) was selected with the aim of characterizing the cellulose content of indoor aerosol particles. Two sets of samples were taken: (1) PM₁₀ collected simultaneously in indoor and outdoor air; (2) PM₁₀ and PM_2.5 collected simultaneously in indoor air. The aerosol particles were concentrated on quartz fibre filters with low-volume samplers equipped with size selective inlets. The filters were weighed and then extracted for cellulose analysis by an enzymatic method. The average indoor cellulose concentration was 1.01 ± 0.24 μg m^?3, whereas the average outdoor cellulose concentration was 0.078 ± 0.047 μg m^?3, accounting for 4.0% and 0.4%, respectively, of the PM₁₀ mass. The corresponding average ratio between indoor and outdoor cellulose concentrations was 11.1 ± 4.9, indicating that cellulose particles were generated indoors, most likely due to the handling of cotton-made textiles as a result of routine daily activities in the bedroom. Indoor cellulose concentrations averaged 1.22 ± 0.53 μg m^?3 in the aerosol coarse fraction (determined from the difference between PM₁₀ and PM_2.5 concentrations) and averaged 0.38 ± 0.13 μg m^?3 in the aerosol fine fraction. The average ratio between the coarse and fine fractions of cellulose concentrations in the indoor air was 3.6 ± 2.1. This ratio is in line with the primary origin of this biopolymer. Results from this study provide the first experimental evidence in support of a significant contribution of cellulose to the mass of suspended particles in indoor air.     

Effect of long‐term exposure to aluminum and high‐fat diet on NTPDase and 5′‐nucleotidase activities in lymphocytes and platelets of rats

Aluminum is one of the most abundant metals in the earth's crust. Although it shows no known biological function, it is recognized as an adjuvant in vaccines for human and veterinary uses. This study aims to evaluate the role of lifestyle and environment in the promotion of chronic disease. In it, we associated two factors: chronic exposure to aluminum and high‐fat diets. Thus, we aimed to determine whether the association of long‐term exposure to aluminum and high‐fat diets affects the NTPDase and 5′‐nucleotidase activities in the blood platelets and lymphocytes obtained from the mesenteric lymph nodes of young rats. In fact, the ectonucleotidase activities were shown to be upregulated upon exposure to aluminum plus high‐fat diets. As a result, we can suggest that the progressive upregulation of ectonucleotidase activities that we observed could be controlling the extent of inflammation and immune response.