Biological monitoring of aromatic diisocyanates in workers exposed to thermal degradation products of polyurethanes

Exposure to diisocyanates was assessed by biological monitoring among workers exposed to the thermal degradation products of polyurethanes (PURs) in five PUR-processing environments. The processes included grinding and welding in car repair shops, milling and turning of PUR-coated metal cylinders, injection moulding of thermoplastic PUR, welding and cutting of PUR-insulated district heating pipes during installation and joint welding, and heat-flexing of PUR floor covering. Isocyanate-derived amines in acid-hydrolysed urine samples were analysed as perfluoroacylated derivatives by gas chromatography mass spectrometry in negative chemical ionisation mode. The limits of quantification (LOQs) for the aromatic diamines 2,4- and 2,6-toluenediamine (2,4- and 2,6-TDA) and 4,4'-methylenedianiline (4,4'-MDA) were 0.25 nmol l(-1), 0.25 nmol l(-1) and 0.15 nmol l(-1), respectively. The LOQ for the aliphatic diamines hexamethylenediamine (HDA), isophoronediamine (IpDA) and 4,4'-diaminodicyclohexyl methane (4,4'-DDHM) was 5 nmol l(-1). TDA and MDA were detected in urine samples from workers in car repair shops and MDA in samples from workers welding district heating pipes. The 2,4-TDA isomer accounted for about 80% of the total TDA detected. No 2.6-TDA was found in the urine of non-exposed workers. The highest measured urinary TDA and MDA concentrations were 0.79 nmol mmol(-1) creatinine and 3.1 nmol mmol(-1) creatinine, respectively. The concentrations found among non-exposed workers were 0.08 nmol mmol(-1) creatinine for TDA and 0.05 nmol mmol(-1) creatinine for MDA (arithmetic means). Exposure to diisocyanates originating from the thermal degradation of PURs are often intermittent and of short duration. Nevertheless, exposure to aromatic diisocyanates can be identified by monitoring diisocyanate-derived amines in acid-hydrolysed urine samples.     

Public Perceptions and Acceptance of Intensive Forestry in Sweden

The use of intensive forestry on part of the forested area in Sweden increases the production of forest biomass and enables an increased use of such biomass to mitigate climate change. However, with increasing conflicting interests in forests and forestry, the success of such a strategy depends on the public acceptance. In this paper, the results of a mail survey show that although a majority of the general public in Sweden supports measures to increase forest growth, they oppose the use of intensive forestry practices such as the cultivation of exotic tree species, clones, and forest fertilization. The acceptance of such practices is mainly influenced by the perceptions of their environmental consequences. Public acceptance was highest for forest fertilization, whereas clone cultivation was the least accepted practice.     

The Future of Baltic Sea Populations: Local Extinction or Evolutionary Rescue?

Environmental change challenges local and global survival of populations and species. In a species-poor environment like the Baltic Sea this is particularly critical as major ecosystem functions may be upheld by single species. A complex interplay between demographic and genetic characteristics of species and populations determines risks of local extinction, chances of re-establishment of lost populations, and tolerance to environmental changes by evolution of new adaptations. Recent studies show that Baltic populations of dominant marine species are locally adapted, have lost genetic variation and are relatively isolated. In addition, some have evolved unusually high degrees of clonality and others are representatives of endemic (unique) evolutionary lineages. We here suggest that a consequence of local adaptation, isolation and genetic endemism is an increased risk of failure in restoring extinct Baltic populations. Additionally, restricted availability of genetic variation owing to lost variation and isolation may negatively impact the potential for evolutionary rescue following environmental change.     

Potential environmental influence of amino acids on the behavior of ZnO nanoparticles

The fate of nanomaterials when they enter the environment is an issue of increasing concern and thus it is important to know how they interact with natural organic molecules since this may have a significant impact on the particles' behavior. Because of our poor knowledge in this regard, the interaction of ZnO nanoparticles with amino acids of contrasting surface charge, including Histidine (HIS), Glycine (GLY), Aspartic acid (ASP) and Glutamic acid (GLU) which occur commonly in natural habitats, such as the plant root zone, was investigated over a range of pH conditions and concentrations. The addition of the individual amino acid led to significant changes in nanoparticle colloidal zeta potential stability, particle size distribution and the extent of agglomeration. Variations in pH resulted in considerable changes in nanoparticle surface charge and hydrodynamic size. In general, the particle size distribution decreased as the amino acid concentration increased, with more acidic conditions exacerbating this effect. In addition, increased concentrations of amino acids resulted in more stable nanoparticles in aqueous suspensions. Histidine had the greatest effect on colloidal stability, followed by Glycine, Aspartic acid and finally Glutamic acid. This study illustrates how nanoparticle behavior may change in the presence of naturally occurring amino acids, an important consideration when assessing the fate of nanoparticles in the environment. Additionally, utilization of amino acids in industrial processes could reduce particle agglomeration and it could lead to a way of employing more sustainable reagents.     

Sex-specific reproductive behaviours and paternity in free-ranging Barbary macaques (Macaca sylvanus)

In a wide variety of species, male reproductive success is determined by contest for access to females. Among multi-male primate groups, however, factors in addition to male competitive ability may also influence paternity outcome, although their exact nature and force is still largely unclear. Here, we have investigated in a group of free-ranging Barbary macaques whether paternity is determined on the pre- or postcopulatory level and how male competitive ability and female direct mate choice during the female fertile phase are related to male reproductive success. Behavioural observations were combined with faecal hormone analysis for timing of the fertile phase (13 cycles, 8 females) and genetic paternity analysis (n = 12). During the fertile phase, complete monopolisation of females did not occur. Females were consorted for only 49% of observation time, and all females had ejaculatory copulations with several males. Thus, in all cases, paternity was determined on the postcopulatory level. More than 80% of infants were sired by high-ranking males, and this reproductive skew was related to both, male competitive ability and female direct mate choice as high-ranking males spent more time in consort with females than low-ranking males, and females solicited copulations mainly from dominant males. As most ejaculatory copulations were female-initiated, female direct mate choice appeared to have the highest impact on male reproductive success. However, female preference was not directly translated into paternity, as fathers were not preferred over non-fathers in terms of solicitation, consortship and mating behaviour. Collectively, our data show that in the Barbary macaque, both sexes significantly influence male mating success, but that sperm of several males generally compete within the female reproductive tract and that therefore paternity is determined by mechanisms operating at the postcopulatory level.     

Entfernung von Schwermetallen aus einem Boden mit hohem Schluffanteil

A soil, containing 2.8% organic carbon and a high concentration (76.4%) of small particles (<63 μm), and which had been contaminated over a long period of time by galvanic waste waters (Ni, Cu) and lead wastes, was subjected to detailed analysis and subsequently treated with various extracting solutions in order to remove the heavy metals. For this purpose, representative samples containing 114 mg kg^?1 Cu, 1151 mg kg^?1 Ni and 366 mg kg^?1 Pb were treated with amino acids and solutions containing other complexing agents, as well as with diluted acids, in order to compare the relative effectiveness of these solutions. Satisfactory metal extractions were only achieved by the use of diluted mineral acids, notably hydrochloric acid, which released more than 90% of the nickel and approximately 80% of the copper and lead from the soil. The results obtained with weak complexing agents such as tartaric acid (0.07–2.9%, 24 h) and amino acids (0.01–36%, 24h) were worse. For reprocessing of the hydrochloric acid solutions, a direct precipitation of the heavy metals in their hydroxide forms and selective separation with N-acylthiourea modified polysiloxanes were carried out.     

Die Wirkung von Cadmium auf Wachstum und Stoffwechsel von Saccharomyces- und Rhodotorula-Zellen

The effect of cadmium chloride on growth and metabolism was tested in Saccharomyces cerevisiae and Rhodotorula rubra.The uptake of cadmium in both yeast strains is the same, but Saccharomyces cells are much more sensitive to cadmium than Rhodotorula cells. In both yeast strains the effect of cadmium on protein synthesis and on transport of glucose or adenine through membranes is very low, the effect on RNA- and ribosome synthesis very high.     

Wirkung von Isoproturon auf Laich und Larven zweier Unkenarten (Bombina spec.)

In intensively used arable areas, a contamination of the reproduction ponds with pesticides probably impairs the development of spawn and tadpoles of amphibians, based on the coincidental space and time. Therefore, the effects of the herbicide isoproturon (IPU) on the early life stages of the firebellied toad (Bombina bombina) and the closely related yellowbellied toad (Bombina variegata) were investigated. The results of the exposure with¹⁴C-labelled IPU (1 μg/L) indicated an uptake into the spawn and tadpoles of bothBombina species. The jelly capsules could not protect the embryo from effects of the herbicide. Tadpoles with complete opercula and without external gills were most sensitive to contamination by IPU. Physical and behavioral abnormalities of the tadpoles developed at concentrations, of 0.1 μg/L after 24 h exposure. At increasing IPU-concentrations the number of impaired and dead tadpoles increased significantly compared to the control. The enzymatic system of the Glutathion S-Transferase (GST) of theBombina tadpoles were influenced significantly by the duration and concentration of IPU exposure. Compared to the pure active ingredient IPU, the commercial herbicide TOLKAN FLO^® provoked a stronger enzymatic response in the tadpoles. This could be caused by the presence of an emulsifier used in the TOLKAN FLO^® formulation which enhanced the availability of IPU and/or the interaction between IPU and the emulsifier.     

在瑞典白尾海雕(Haliaeetus albicilla)繁殖过程中DDE、PCB、共面PCB和蛋壳参数所起的作用

1964～1999年,对三个受不同污染的瑞典白尾海雕亚种群[波罗的海沿岸种群(Bp)、瑞典中部内陆种群(Ip)和拉普兰种群(Lp)]的繁殖进行了监测.     

"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.