A bioassay approach to determine the dioxin-like activity in sediment extracts from the Danube River: ethoxyresorufin-O-deethylase induction in gill filaments and liver of three-spined sticklebacks (Gasterosteus aculeatus L.)

Sediment samples from the upper Danube River in Germany have previously been characterized as ecotoxicologically hazardous and contaminants in these sediments may contribute to the observed decline of fish populations in this river section. For the investigation of sediment toxicity there is a need for development, standardization and implementation of in vivo test systems using vertebrates. Therefore, the main objective of this study was to apply and evaluate a recently established fish gill EROD assay as a biomarker in sediment toxicity assessment by using extracts of well characterised sediment samples from the upper Danube River. This to our knowledge is the first application of this novel assay to sediment extracts. Sediments from four different sites along the upper Danube River were Soxhlet-extracted with acetone and dissolved in DMSO. Three-spined sticklebacks (Gasterosteus aculeatus L.) were exposed for 48 h to various concentrations of the extracts, to the positive control beta-naphthoflavone or to the solvent. Measurements of EROD activity in gill filaments and liver microsomes followed the exposure. Concentration-dependent induction of EROD in both gill and liver was found for all sediment extracts. The highest EROD-inducing potency was determined for extracts of sediments from the sites "Opfinger See" and "Sigmaringen" and the EROD activities in gill and liver correlated well. The results from the gill and liver assays were in accordance with in vitro results of previous investigations. The EROD activities measured in the present study corresponded with the concentrations of PAHs, PCBs and PCDD/Fs in the sediment samples derived in a previous study. The sticklebacks in this study were in the reproductive phase and a stronger EROD induction was obtained in the females than in the males. Implementation of the EROD assay in testing of sediment extracts gave highly reliable results which make this assay an ecotoxicologically relevant method for assessment of contamination with Ah receptor agonists in sediments.     

137Cs and 90Sr in live and dead reindeer lichens (genera Cladonia) from the "Kraton-3" underground nuclear explosion site

The contents of 137Cs and 90Sr have been determined in 29 samples of live and dead reindeer lichens (genera Cladonia) collected at the "Kraton-3" underground nuclear explosion site (65.9 degrees N 112.3 degrees E, event year--1978) in Yakutia, Russia in 2002. The area contamination was within the range of 0.36-700 and 0.13-770 kBq m(-2) for 137Cs and 90Sr, respectively. The dead organisms were on average much more contaminated than the live ones. Vertical fractionation of the live lichen carpet demonstrated maximal activity concentrations of both radionuclides in the lower older section of the plants, while for the dead lichens the maximal activity concentrations of 137Cs were detected in the upper part. The vertical distribution of 90Sr was more or less homogeneous in the cushions of dead lichens. Elevated levels of 137Cs and 90Sr activity concentrations were also detected in the re-establishing young lichens growing over the residua of some dead lichens.     

Recent Trends and Patterns of Nutrient Concentrations in Small Agricultural Streams in Sweden

Long-term median total phosphorus (TotP) and total nitrogen (TotN) concentrations were 0.08 and 5.5 P/N (mg L^-1), respectively, in 10 agricultural streams monitored since 1988 in Sweden. The areas ofthe respective catchments are 2–20 km². The period 1992/2002 was characterised by stable hydrological conditions without any flow trends in nearly all of the streams. The highest average TotP concentration, 0.17 mg P L^-1, was found in a small agriculturalstream in the largest Swedish agricultural plain. The soil texture is here characterised by a large specific surface area of the soil particles, and the agriculture by cereal production. The second highestaverage TotP concentration, 0.14 mg P L ^-1, was measured in the surface water from a catchment characterised partly by clay soils andby production of potato, spring cereals and grass. This catchment had twice as many fields with a calculated high risk for P losses comparedwith another monitored catchment in the same watershed (River Rönneå). There was a significant downward TotP trend during 1992/2002 of 0.0012 mg P L^-1 yr^-1 (Sen's slope estimator) in the catchment where many fields risk P losses and which had a reduced P manure application rate of –20% during 1995/2000. In recent years practically no manure has been spread during autumn. Bypass flow of nitrate through one soil has been suggested to influence the LOWESS (LOcally WEighted Scatterplot Smothing) fitting curve of TotN. Total nitrogen concentration decreased in most of the catchment. The average downward slope was similar to a general TotN reduction of 0.069 mg N L^-1 yr^-1. During the period 1992/2002 this was equal to slightly more than 10 per cent. Cultivation of catch crops wasrelatively uncommon until 2002, but this practice is expected to expandto larger areas during 2003 and in the future.     

Where Technology Goes to Die: Representations of Electronic Waste in Global Television News

This article analyzes how electronic waste (e-waste) gets represented in television news stories. The main objective is to present a perspective on how a “low-frequency” emergency (i.e. a lengthy and ongoing state of environmental emergency) is presented as a newsworthy issue. Drawing on literature on televised “distant suffering,” the article engages in a multimodal text analysis of four news stories about e-waste. The findings show how on-location reports from e-waste dumping sites make use of sublime imagery in the visual representations; how e-waste dumping sites are presented as strange spaces, with no clear and comprehensible history; and finally, that the representations suggest an ambivalence and uncertainty when it comes to agency (who is responsible and what can be done?). The article ends with a discussion of the implications of this mode of representation and its effectiveness in eliciting an appropriate response to the harms caused by e-waste.     

Baltic Sea management: Successes and failures

Severe environmental problems documented in the Baltic Sea in the 1960s led to the 1974 creation of the Helsinki Convention for the Protection of the Marine Environment of the Baltic Sea Area. We introduce this special issue by briefly summarizing successes and failures of Baltic environmental management in the following 40 years. The loads of many polluting substances have been greatly reduced, but legacy pollution slows recovery. Top predator populations have recovered, and human exposure to potential toxins has been reduced. The cod stock has partially recovered. Nutrient loads are decreasing, but deep-water anoxia and cyanobacterial blooms remain extensive, and climate change threatens the advances made. Ecosystem-based management is the agreed principle, but in practice the various environmental problems are still handled separately, since we still lack both basic ecological knowledge and appropriate governance structures for managing them together, in a true ecosystem approach.     

"21世纪的食物":寻找增进食物链可持续性的措施和工具的研究计划

"21世纪的食物",是一项包括整个农业食物链的跨学科研究计划,于1997～2004年在瑞典实施.该研究所面临的挑战是为整个食物链中存在的不可持续的活动提出环境分析工具和解决方案.这需要科学家和食物链利益相关人紧密合作.本文提出了一整套以可持续食物生产为特征的目标方案.综合和系统分析是用来分析拟定变化的可持续性的主要工具.在本文中我们对"21世纪的食物"的概念进行概述,同时着重说明一些结论.例如,我们发现:就环境影响和产品质量而言,总体上来说,有机农业及其产品并不比常规的产品和方法优越.项目所采用的一些管理经验非常独特,这也是项目成功完成的重要原因,所以本文中我们对此也进行了总结.     

Macrophyte development and habitat characteristics in Sweden's large lakes

The four largest Swedish lakes, V?nern, V?ttern, Hj?lmaren, and M?laren, were surveyed by means of aerial IR-color photography in the 1970s. Along small slope gradients in all lakes the emergent communities extended to a width of hundreds of meters, while the extent on steeper slopes was a few meters. Because of the fractionate shape, L. M?laren has a very long shoreline, which promotes vegetation growth in the transition zone between land and water. Sheltered conditions are numerous and water lilies and other floating leaved and freely floating plants are abundant. Emergent as well as submerged macrophytes grow vigorously in the northernmost part of the oligotrophic lake V?ttern. In L. V?nern exposed shores pre-dominate, but sheltered bays and archipelagos are overgrown with reeds. In the shallow lake Hj?lmaren monospecific stands of Phragmites australis are dominant. Recurrent surveys of L. M?laren and L. V?nern in the 1990s showed changes that could be connected to the watertable fluctuations, which have been stabilized since the first investigation. Reeds and water lilies expanded in sheltered parts of the lakes, while the distribution of reed stands growing at their deep limit decreased.     

On the perchlorination of 2-hydroxybiphenyl and 2-(2,4-dichlorophenoxy)-4,5,6-trichlorophenol and their methyl ethers

2-Hydroxybiphenyl and 2-(2,4-dichlorophenoxy)-4,5,6-trichlorophenol and their methyl ethers were perchlorinated with four different reagents of various strengths. It was shown that perchlorination is not a reliable method in the analysis of these compounds. Pure octachlorodibenzofuran and nonachlorohydroxybiphenyl were, however, synthesized by the perchlorination procedure.     

An assessment of cumulative external doses from Chernobyl fallout for a forested area in Russia using the optically stimulated luminescence from quartz inclusions in bricks

Optically stimulated luminescence (OSL) has been used for estimation of the accumulated doses in quartz inclusions obtained from two fired bricks, extracted in July 2004 from a building located in the forested surroundings of the recreational area Novie Bobovichi, the Bryansk Region, Russia. The area was significantly contaminated by Chernobyl fallout with initial (137)Cs ground deposition level of approximately 1.1 MBq m(-2). The accumulated OSL doses in sections of the bricks varied from 141 to 207 mGy, of which between 76 and 146 mGy are attributable to Chernobyl fallout. Using the OSL depth-dose profiles obtained from the exposed bricks and the results from a gamma-ray-survey of the area, the Chernobyl-related cumulative gamma-ray dose for a point detector located in free air at a height of 1m above the ground in the study area was estimated to be ca. 240 mGy for the time period starting on 27 April 1986 and ending on 31 July 2004. This result is in good agreement with the result of deterministic modelling of the cumulative gamma-ray dose in free air above undisturbed ground from the Chernobyl source in the Bryansk Region. Over the same time period, the external Chernobyl-related dose via forest pathway for the most exposed individuals (e.g., forest workers) is estimated to be approximately 39 mSv. Prognosis for the external exposure from 1986 to 2056 is presented and compared with the predictions given by other investigators of the region.