Experimental investigation of outdoor and indoor mean concentrations and concentration fluctuations of pollutants

Tracer gas was released upwind of a two-compartment complex shaped building under unstable atmospheric conditions. The mean wind direction was normal to or at 45° to the long face of the building. The general patterns of concentration distribution on the building external walls and inside the building were analysed and the influence of natural and mechanical ventilation on indoor concentration distributions was discussed. Mean concentration levels, as well as the concentration fluctuation intensity, were higher on the windward walls of the building, although concentration levels varied along each wall. Concentration fluctuations measured inside the building were lower than those measured outside. Inside the two compartments of the building, the time series of concentrations had a similar general behaviour; however, gas concentrations took approximately 1.5 times longer to reach the mean maximum concentration value at the downwind compartment 02 while they also decreased more rapidly in the upwind compartment 01 after the source was turned off. The highest indoor concentration and concentration fluctuation values were observed at the detectors located close to the windward walls, especially when the building windows were open. Experiments with and without natural ventilation suggested that infiltration and exfiltration of contaminants is much faster when the building windows are open, resulting to higher indoor concentration levels. Furthermore, mechanical ventilation tends to homogenize concentrations and suppress concentration fluctuations, leading to lower maximum concentration values.     

Assessment of organochlorine pesticide residues in Atlantic Rain Forest fragments, Rio de Janeiro, Brazil

A superficial water quality survey in a watershed of the Paraíba do Sul River, the main water supply for the most populated cities of southeastern Brazil, was held in order to assess the impact of the expansion of agricultural activity in the near border of the Atlantic Rain Forest. The aim of this study was to investigate the presence of priority organochlorine pollutants in soils and superficial waters of Atlantic rainforest fragments in Teresópolis, Rio de Janeiro State. Soil sample preparations were compared by using ultrasound, microwave assisted extraction and Soxhlet extraction. Recoveries of matrix spiked samples ranged from 70 to 130%. Analysis of a certified soil material showed recoveries ranging from 71 to 234%. Although low concentrations of organochlorine residues were found in water and soil samples, this area is of environmental importance and concern, thus demanding a monitoring program of its compartments.     

Sugarcane vinasse: Environmental implications of its use

The inadequate and indiscriminate disposal of sugarcane vinasse in soils and water bodies has received much attention since decades ago, due to environmental problems associated to this practice. Vinasse is the final by-product of the biomass distillation, mainly for the production of ethanol, from sugar crops (beet and sugarcane), starch crops (corn, wheat, rice, and cassava), or cellulosic material (harvesting crop residues, sugarcane bagasse, and wood). Because of the large quantities of vinasse produced, alternative treatments and uses have been developed, such as recycling of vinasse in fermentation, fertirrigation, concentration by evaporation, and yeast and energy production. This review was aimed at examining the available data on the subject as a contribution to update the information on sugarcane vinasse, from its characteristics and chemical composition to alternatives uses in Brazil: fertirrigation, concentration by evaporation, energy production; the effects on soil physical, chemical and biological properties; its influence on seed germination, its use as biostimulant and environmental contaminant. The low pH, electric conductivity, and chemical elements present in sugarcane vinasse may cause changes in the chemical and physical–chemical properties of soils, rivers, and lakes with frequent discharges over a long period of time, and also have adverse effects on agricultural soils and biota in general. Thus, new studies and green methods need to be developed aiming at sugarcane vinasse recycling and disposal.     

Demonstrations of coal-fired oxy-fuel technology for carbon capture and storage and issues with commercial deployment

As one of the three major carbon capture technologies associated with carbon capture and storage (CCS), oxy-fuel technology is currently undergoing rapid development with a number of international demonstration projects of scale 10–30 MW_e having commenced and units with a scale of 250–300 MW_e emerging in the progression towards commercialisation. Industrial scale testing of coal combustion and burners is also being conducted by technology vendors.The paper details the current international status of the technology; the contributions of current demonstrations; and a roadmap for commercial deployment.At its current state of maturity oxy-fuel technology may be considered semi-commercial, in that even if a unit was economically viable and could be provided by a vendor, the generator and vendor would need to share the technical risk. This is because guarantees could not at present be provided for operating characteristics associated with mature technologies such as reliability, emissions, ramp rate and spray control. This is due to the maturity of the technology associated with the capability of vendors and associated design and operational uncertainties, associated with a lack of plant experience at scale.The projected development of oxy-fuel technology for first-generation plant is provided, using an ASU for oxygen supply, standard furnace designs with externally recirculated flue gas, and limited thermal integration of the ASU and compression plant with the power plant. Potential features of second generation technology are listed.Listed issues delaying deployment indicate that market, economic, legal and issues of public acceptance are more significant than technical barriers.     

The impact of urbanization on tropical mangroves (Fortaleza,Brazil): Evidence from PAH distribution in sediments

This investigation represents the first environmental diagnosis of the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments from a tropical mangrove in Fortaleza, northeastern Brazil. Sediment cores from six sampling stations in the Cocó and Ceará Rivers were retrieved in June-July 2006 to determine 17 priority PAHs. The total PAH concentrations (Σ_PAHs) ranged from 3.04 to 2234.76 μg kg^?1(Cocó River) and from 3.34 to 1859.21 μg kg^?1 (Ceará River). These levels are higher than those of other cities with more industrial development. PAH concentrations did not reach probable effect levels (PELs). However, from 4.5 to 87.5% of individual PAH concentrations can occasionally cause adverse biological effects for aquatic organisms. The PAH molecular ratios indicate that the PAHs in the sediment core were derived mainly from petroleum, wood, and charcoal combustion (pyrogenic source), and that atmospheric deposition and urban runoff may serve as important pathways for PAH input to the sediment. Clearly, the Σ_PAHs in sediments collected in the Cocó and Ceará Rivers indicate that ongoing pollution is more severe than past pollution.     

A critical look at residential electricity conservation campaigns in a developing country environment

This paper analyses survey results of the effectiveness of information campaigns to promote energy efficiency among residential consumers in Brazil. The survey found that consumers have a relatively good knowledge of conservation measures to improve electricity usage. Nevertheless, other approaches are needed to promote energy conservation in the household sector.     

Anguilla anguilla L. plasma cortisol, lactate and glucose responses to abietic acid, dehydroabietic acid and retene

Anguilla anguilla L. were exposed to 0, 0.1, 0.3, 0.9 and 2.7 microM abietic (AA), dehydroabietic (DHAA) acids and retene (Re) during 8, 16, 24 and 72 h. The eels plasma cortisol, glucose and lactate were measured. A significant decrease in plasma cortisol was observed at 72 h exposure to 0.9 and 2.7 microM Re. DHAA (0.1 microM) significantly decreased plasma cortisol in eels after 8 and 24 h exposure. However, a significant plasma cortisol increase was found after 16 h, 2.7 microM AA exposure and after 24 h exposure to 0.1 microM and 2.7 microM AA. Furthermore, 72 h exposure to 0.9 microM AA also induced a plasma cortisol increase. A general rise in plasma glucose was detected after all exposure periods to Re. The plasma lactate also increased after 72 h exposure to 2.7 microM AA and after 8 h exposure to 0.1 microM DHAA.     

Daily ingestion of 232Th, 238U, 226Ra, 228Ra and 210Pb in vegetables by inhabitants of Rio de Janeiro City

The concentrations of the naturally occurring radionuclides 232Th, 238U, 210Pb, 226Ra and 238Ra were determined in the vegetables (leafy vegetables, fruit, root, bean and rice) and derived products (sugar, coffee, manioc flour, wheat flour, corn flour and pasta) consumed most by the adult inhabitants of Rio de Janeiro City. A total of 88 samples from 26 different vegetables and derived products were analyzed. The highest contribution to radionuclide intake arises from bean, wheat flour, manioc flour, carrot, rice, tomato and potato consumption. The estimated daily intakes due to the consumption of vegetables and derived products are 1.9 mBq of 232Th (0.47 microg), 2.0 mBq of 238U (0.17 microg), 19 mBq of 236Ra, 26 mBq of 210Pb and 47 mBq of 228Ra. The estimated annual effective dose due to the ingestion of vegetables and their derived products with the long-lived natural radionuclides is 14.5 microSv. Taking into account literature data for water and milk from Rio de Janeiro the dose value increases to 29 microSv, with vegetables and derived products responsible for 50% of the dose and water for 48%. 210Pb (62%) and 228Ra (24%) were found to be the main sources for internal irradiation.     

Exposure of workers in mineral processing industries in Brazil

The mining, milling and processing of uranium and thorium bearing minerals may result in radiation doses to workers. A preliminary survey pilot program, that included six mines in Brazil (two coal mines, one niobium mine, one nickel mine, one gold mine and one phosphate mine), was launched in order to determine the need to control the radioactive exposure of the mine-workers. Our survey consisted of the collection and analysis of urine samples, complemented by feces and air samples. The concentrations of uranium, thorium and polonium were measured in these samples and compared to background data from family members of the workers living in the same dwelling and from residents from the general population of Rio de Janeiro. The results from the coal mines indicated that the inhalation of radon progeny may be a source of occupational exposure. The workers from the nickel, gold and phosphate mines that were visited do not require a program to control internal radiological doses. The niobium mine results showed that in some areas of the industry exposure to thorium and uranium might occur.     

Liver glutathione content and glutathione‐dependent enzymes of two species of freshwater fish as bioindicators of chemical pollution

Abstract

Glutathione content and glutahione‐dependent enzymes were measured in the liver of two fish species, gudgeon (Gobio gobio) and roach (Rutilus arcasii), from the river Bernesga (Spain) caught downstream and upstream of the waste site of several chemical industries. Animals from contaminated sites display a reduced glutathione concentration and a tendency to the decrease of glutathione S‐transferase activity. Glutathione peroxidase activity was significantly elevated only in the liver of Gobio gobio and glutathione reductase activity in that of Rutilus arcasii. Our data indicate that the glutathione system constitutes a sensitive biochemical indicator of chemical pollution. Relative changes of glutathione and glutathione‐dependent enzymes in both fish species suggest a different susceptibility to toxins.