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.     

Characterisation of DNA probes for the analysis of metallothionein gene expression in the bank vole (Clethrionomys glareolus)

DNA probes have been developed for subsequent use in monitoring the exposure of animals to heavy metal pollution in terrestrial environments using metallothionein (MT) gene expression in the bank vole (Clethrionomys glareolus). Three different bank vole sequences were characterised corresponding to the cDNA and the genomic DNA for MT-I and the genomic DNA for MT-II. Nucleotide sequence analysis indicates that the coding sequences of the bank vole MT-I and MT-II genes exhibit a very high degree of similarity (greater than 92%) to the corresponding genes of the Chinese hamster, the mouse and the rat. In common with other mammalian MT genes, both the MT-I and MT-II genes in the bank vole are interrupted by two introns, which are at identical positions as those in other rodent MT genes; furthermore, the sizes of these introns are similar to those in other rodents with the first intron being larger than the second and those in the MT-I gene being larger than those in the MT-II gene. The predicted amino acid sequence for the proteins shows that both proteins contain 20 cysteine residues at positions identical to those in other known mammalian MTs. The availability of these DNA sequences now provides a good opportunity to investigate MT gene expression and possible gene amplification in bank voles exposed to metal 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.     

An Ecological Integrity Index for Littoral Wetlands in Agricultural Catchments of Semiarid Mediterranean Regions

The main goal of the present study was to develop an ecological integrity index for littoral wetland management and conservation in semiarid Mediterranean areas that have been highly impacted by agriculture, including the selection of pressure and state indicators at landscape and wetlands scales that reflect the status, condition, and trends of wetlands ecosystems. We used a causality framework based on the relationship between pressure of anthropogenic activities and the ecological state of wetlands and their catchments, integrating environmental, biologic, economic, and social issues. From the application of 51 indicators in 7 littoral wetlands in the southeastern Iberian Peninsula, we selected 12 indicators (5 at catchment scale and 7 at wetland scale) to constitute the ecological integrity index proposed. The potential nitrogen export per area at catchment scale and the potential relative nitrogen export from the area surrounding the wetlands were the best pressure single predictors of state indicators with a causal relationship with environmental meaning. Wetlands in catchments with more agriculture had less ecological integrity than those in less impacted areas. A wide riparian zone in some wetlands acts as a buffer area, diminishing the effects of intensive agriculture. The index of ecological integrity developed here has a number of essential characteristics that make it a useful tool for ecosystem managers and decision-makers. The index can be used to (1) assess and control ecological integrity, (2) diagnose probable causes of ecological impairment, (3) establish criteria for protecting and restoring wetland ecosystems, and (4) integrate catchment management. Published online     

Vitellogenin induction in Cyprinus carpio treated with 17beta-estradiol and 4-nonylphenol

The aim of the present study was to demonstrate induction ofvitellogenin in the common carp (Cyprinus carpio) as abiomarker for monitoring freshwater ecosystems. Sexually undifferentiated specimens of common carp were treated experimentally with 17-estradiol and increasing doses of 4-nonylphenol and levels of plasma Vtg were measured in orderto: 1) validate an ELISA assay for plasma Vtg in the common carpusing the polyclonal rabbit anti-salmon Vtg antibody AA1 (Biosense, Norway); 2) check the sensitivity of carp juvenilesin producing Vtg in response to estrogen stimulation. The grouptreated with 17-estradiol showed high induction (156%)with respect to controls, also groups treated with 4-nonylphenolshowed induction of Vtg. The group treated with 100 mg kg^-1b.wt showed an induction of 61%. A statistically significantcorrelation was found between dose and response. This preliminary study demonstrate a response to the ELISA assay for Vtg in the common carp using rabbit anti-salmon antibody AA1. With further evidence the tested biomarker might be proposed for large scale monitoring of estrogenic effects caused by pollution in urban and industrial effluents.     

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.     

Elemental and isotopic determination of lead (Pb) in particulate matter in the Brazilian city of Goiânia (GO) using ICP-MS technique

Environmental Science and Pollution Research - The toxic metal lead (Pb) can be harmful to human health in various manners, but is also considered as a distinguished tracer of environmental...