Passive and Active Sampling of Benzene in Different Urban Environments in Gothenburg, Sweden

Urban benzene concentration and personal exposure to benzene were measured within different urban environments in Gothenburg, Sweden. Three intensive monitoring campaigns were carried out in May 2000, February 2001 and May 2001. Three different environments were selected; two central built-up areas with different traffic densities (high and low) and one large urban park. The methods used included passive and active sampling. Passive sampling was used to retrieve spatial variability in urban benzene concentrations, while active sampling aimed to give data on personal exposure levels within the designated areas. The passive sampling showed large spatial and temporal variations in urban benzene concentrations. The benzene concentrations, ranging from 1.0 to 3.1 μg m^?3, were typically two to four times higher within the high-traffic built-up area compared to the adjacent urban park. This was mainly due to the proximity to motorised traffic. A comparison between personal exposure and active stationary measurements showed that the personal exposure levels were roughly 1.5 times higher in the heavy traffic area and 1.3 times higher in the light traffic area than the fixed benzene concentrations. The personal exposure levels in the park were equal to the active stationary benzene concentration. Given the large spatial heterogeneity within urban areas, the placement of single street level point measurements becomes crucial. Care must be taken to ensure that the measurements are actually representative when using these measurements to estimate urban concentrations and exposure levels.     

Monitoring fish stocks in relation to acidification in Norwegian watersheds

The Norwegian Monitoring Programme for Long-Range Transported Air Pollutants started in 1980. The biological part of this programme includes besides invertebrate studies in streams, (i) fish community status in lakes by means of interviews, test-fishing in lakes by using standard gill-net series, recruitment studies of brown trout in inland streams, and juvenile stock assess and monitoring of fish kills in salmon rivers. Damaged fish stocks are recognized within a land area of 51,500 km² in southern Norway and 30 km² in northern Norway. At least 6,000 lake-dwelling fish stocks have either been lost or are at various stages of reduction. Brown trout (Salmo trutta) is the most widespread and abundant species of fish in Norwegian watersheds, and is also most severe affected by acidification. More recently, there are some indications of an increase in the abundance of brown trout in some areas. However, analysis of age structure in lakes, and fry densities in streams in such areas revealed large annual variations in recruitment rate, which indicates unstable water chemical conditions. Atlantic salmon (Salmo salar) is virtually extinct in 25 rivers in southernmost, southwestern and western Norway.     

Inorganic Constituents of Well Water in One Acid and One Alkaline Area of South Sweden

Acid precipitation may lead to loss of essential elements and increase the concentrations of potentially toxic elements in drinking water. In this study 46 private wells from acid regions(pH < 6.5) were compared with 43 private wells from alkaline areas in southern Sweden. The concentrations of about 30 elementswere analysed especially by inductively coupled plasma opticalemission spectroscopy (ICP-OES). The concentrations of essentialelements such as calcium, chromium, selenium and potassium weresignificantly lower in acid than in alkaline well water. On theother hand, the levels of potentially toxic metals such as cadmium and lead were significantly higher in acid well water. High copper concentrations, observed at pH around 6 in contrast to earlier findings, is to be considered as an acidification problem, as should the high fluoride values. The highest concentrations of a number of metals and ions, for example calcium, chromium, titanium and sulphate, appeared at pH 7.0–8.0, where the peak in concentrations occur due to leachingof metals from soil particles in acid soils and precipitation ofcarbonates and sulphates in more alkaline soils. The low levelsof especially calcium and magnesium ions, and some micronutrientsin the acid water, in combination with high concentrations of acid ions and toxic microelements, may cause nutritional imbalances. This should be regarded as risk factors with relationto effects on human health.     

Shrinking Danish agriculture

Danish agriculture is facing a turning point. Centuries of struggle to increase arable land area as well as its productivity is about to be reversed, due to overproduction and environmental problems. Some land will probably be turned back to nature, and the use of chemicals in agriculture in general will be reduced, perhaps with a lower productivity and a better environment as a consequence. This paper mainly describes some of the political actions taken in Denmark to influence environmental-agricultural issues. First, however, some of the recently perceived environmental problems and over-production problems connected with Danish farming are outlined.     

Prostaglandins: enzymatic analysis

By, means of al specific nicotinamide-adeninie dinucleotide-dependent prostaglanidin dehydrogenase from swine lung, an enizymatic method has been developed for the assay of prostaglandins. The method permits analysis with a lower limit of 10(-12) mole of prostaglandin.     

Diversity of Nordic Landrace Potatoes (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.) Revealed by AFLPs and Morphological Characters

The management of genebank collections of cultivated potato is costly due to the need for in vitro maintenance and virus eradication. Therefore, it is important to set up conservation strategies, which prevent duplicates entering the collections. In this study, 32 Nordic potato landraces were studied for 57 morphological traits and analysed for amplified fragment length polymorphism (AFLP). Most landraces could be distinguished based on the morphological characters, except five accessions. Using five primer combinations to generate 114 reproducible AFLPs, of which 63 (55%) were polymorphic, the five morphologically indistinguishable accessions were placed into two groups with identical AFLP patterns, suggesting that some of the accessions were redundant for long-term preservation. The AFLP data showed that the Nordic collection of potato landraces is composed of genetically different clones, and morphological analysis revealed a wide range of variability. This variability seems to be distributed randomly over the Nordic region since the cluster analysis based on AFLPs and morphological traits revealed no grouping based on the country of origin. Principal component analysis suggests that fewer morphological traits than used in this study will be sufficient to discriminate between different genotypes of cultivated potato (Solanum tuberosum L.). Future possibilities for rationalising potato collections are discussed.     

Two-dimensional gel electrophoresis detection of protein oxidation in fresh and tainted rainbow trout muscle

Protein oxidation is evaluated in rainbow trout muscle by labeling protein carbonyls with 2,4-dinitrophenyl hydrazine (DNPH) followed by immunoblotting of proteins separated by SDS-PAGE or two-dimensional gel electrophoresis (2D-GE). The carbonylation level is accessed on proteins in a whole muscle homogenate or proteins soluble in a high-salt or low-salt buffer. Spoilage-related changes in carbonylation are followed in the high-salt-protein and low-salt-protein fractions by 2D immunoblotting, which reveals increases regarding total number and intensity of carbonylation in both protein fractions for fish kept at room temperature for 48 h. The major amount of carbonylated proteins is found among the high-salt-soluble proteins, and this protein fraction is also responsible for the biggest increase in carbonylation during fish tainting. The results give an estimate of the level of protein carbonylation in rainbow trout and reveal that oxidation increases for a distinct number of proteins during tainting.     

Trophic interactions between rhizosphere bacteria and bacterial feeders influenced by phosphate and aphids in barley

The aim was to study the effects of P fertilization and leaf aphid attack on the trophic interactions of bacteria and bacterial feeders in the rhizospheres of barley plants. The density of protozoa peaked in the rhizospheres of plants fertilized with N and P, whereas nematodes peaked in the rhizospheres of plants to which only N had been added. Fingerprinting of bacterial communities by length heterogeneity polymerase chain reaction revealed differences in community structure between NP rhizospheres and N rhizospheres as well as aphid-related differences within N rhizospheres. Specifically, α-proteobacteria increased with P addition. To evaluate if differences in bacteria in terms of their quality as food could partly explain the observed differences in protozoan and nematode abundances, growth of the flagellate Cercomonas sp. was assessed with 935 bacteria isolated from the different treatments. This assay indicated that bacterial isolates were of higher food quality to Cercomonas sp. in NP than in N rhizospheres when plants were subjected to aphid attack. Bacteria of high and low food quality for Cercomonas sp., respectively, were fed to the nematode Caenorhabditis elegans and larval production examined. α-Proteobacteria supported the growth of Cercomonas sp. well, whereas Actinobacteria did not. In contrast, C. elegans reproduced poorly on most α-proteobacteria but were able to reproduce well on some Actinobacteria. These results suggest that the different response of protozoa and nematodes to P addition could be mediated through a food quality-related change in community composition of bacteria and that leaf aphid attack may interfere with nutrient effects on bacterial assemblages of rhizospheres.     

Recognition of the Nor98 variant of scrapie in the Swedish sheep population.

Within the framework of the active surveillance for transmissible spongiform encephalopathies in sheep in Sweden, 4 cases of the atypical form of scrapie, Nor98, were identified during 2003. Nor98 is a recently recognized and poorly understood variant of scrapie, first described in Norway. The cases were positive by the rapid test (enzyme-linked immunosorbent assay). Immunohistochemical staining showed diffuse thin-granular staining of the cerebellar cortex. Western immunoblotting analysis of specimens of brain stem and cerebellum showed a light band of approximately 12 kDa. Typical scrapie was ruled out based on the confirmatory testing. The affected ewes were from 4 different flocks. They were between 7 and 9 years old. Two were of the ARQ/ARQ genotype, 1 ARR/ARQ, and 1 ARR/AHQ. Two ewes had shown ataxia, and the other 2 had no clinical signs. Whole-flock slaughter was applied, and testing of the flock mates did not reveal additional cases. Nor98 differs from typical scrapie in its epidemiology, frequency of genotypes of sheep affected, clinical signs, microscopic lesions, distribution of scrapie prion protein in the brain, and characteristics of the immunostaining and immunoblotting profiles.