德国志愿协议的作用

志愿协议(VAs)正在作为环境政策的一种新手段出现,因为它们有超过传统政策措施的优势.具体地说,它们是经济上效率更高的.德国工业界涉及众多工业协会、大概是世界上最昂贵的1996年志愿气候保护协议,是以到2005年显著削减CO2为目标的.这项志愿协议的实施是由一个独立机构按年度监测的.从全球来说,志愿协议应当与联合实施和排放交易相互联系,从而使国际气候保护政策更加灵活和成本有效.     

In vitro Screening von Pflanzenschutzmittel-Wirkstoffen auf östrogene Aktivität

Over the last years, the obviously increasing, hormone-dependent impairments observed in humans and animals, as well as the increased occurrence of hormone-dependent types of cancer, are sometimes associated with environmental chemicals which are suspected to imitate or block the effects of natural hormones. For a variety of environmental chemicals an endocrine efficacy could already be demonstrated. Little is known, however, about a possible hormonal activity of plant protection agents which are at present certificated in the Federal Republic of Germany. The aim of the present study was the in vitro testing of at least 57 active ingredients of pesticides and growth regulators certificated in the Federal Republic of Germany, for their possible estrogenic activity. The E-Screen-Assay based on the human breast cancer cell line MCF-7 was used as the suitable test system. For at least 8 of the tested substances, an receptor-mediated estrogenic activity could be shown in vitro. With the exception of one substance, 7 active ingredients displayed a very weak affinity for the human estrogen receptor. Their ability to displace 17β-estradiol from the receptor was low. Only the herbicide Pendimethalin is to be classified as a full estrogen receptor agonist; it is able to displace 17β-estradiol almost completely from the receptor. Howeverm the estrogenic potency of Pendimethalin, in comparison to 17β-estradiol, was seen to be as small as the estrogenic potency of the other 7 substances tested positively in the E-Screen-Assay. Among this 7 substances, two could not be classified as estrogenically active anymore, because their affinity to the human estrogen receptor was too weak. The relevance of the available results for livng organisms should be clarified in further in vivo investigations.     

Objective exposure to road traffic noise,noise annoyance and self-rated poor health – framing the relationship between noise and health as a matter of multiple stressors and resources in urban neighbourhoods

Borrowing from concepts of socio-environmental epidemiology and psychology, we conceived self-rated health as a function of multiple physical and psychosocial stressors and resources at the residential neighbourhood and individual level. In this model of multiple stressors, objective exposure to road traffic noise was specified as a physical stressor whose effect on health may be mediated and modified by residents’ subjective response to noise (serious noise annoyance). Self-reported hearing disability, recreational coping in green areas and residential neighbourhood satisfaction were examined as additional psychosocial stressors or resources, independently of socio-demographic and -economic factors. Results from our empirical analysis based on two studies and multivariable logistic regressions might support the idea that environmental planning should overcome sectoral boundaries and adopt an integrative approach including objective exposures, residents’ subjective responses, and perceived resources.     

Congruence of epicuticular hydrocarbons and tarsal secretions as a principle in beetles

Within beetles, those species that are adapted to life on plants have developed widened tarsi with specialised hairy attachment structures. The capability to adhere to smooth surfaces is based on a liquid film on the surface of these structures, the composition of which is similar to the cuticular lipids. By means of a cluster analysis based on chemical similarities between samples obtained from tarsi or elytra of 35 species using solid phase microextraction, the present study strongly suggests that this chemical congruence is a principle in beetles. This supports the idea of tarsal liquids being part of the cuticular lipid layer and contributes to the understanding of liquid-mediated attachment systems.     

Atmospheric Aerosols: Size Distribution Interpretation

The body of information presented in this paper is directed towards the scientist or engineer who measures and interprets the physical characteristics of ambient air. This paper interprets measurements made with the Minnesota Aerosol Analyzing System (MAAS) in Denver, near Denver, and near Ft. Collins, Colo., and examines the measurements in the light of what has been learned from several thousand size distributions measured in the other parts of the United States. The origin and physical change of atmospheric particulates is examined through interpretation of modes occurring in the size distributions. The mode coined “AHken Nuclei Range” mode is a measure of aerosol generation, while aged aerosols show up in the “Accumulation Range” mode. Windblown dusts, sea sprays, and mechanically produced particles such as fly ash generate a “Coarse Particle Range” mode. The air environment is categorized into several types of background and urban aerosols whose physical characteristics are described by a limited number of parameters. These categories are exemplified and discussed.     

Growing season methane budget of an Inner Mongolian steppe

We present a methane (CH₄) budget for the area of the Baiyinxile Livestock Farm, which comprises approximately 1/3 of the Xilin river catchment in central Inner Mongolia, P.R. China. The budget calculations comprise the contributions of natural sources and sinks as well as sources related to the main land-use in this region (non-nomadic pastoralism) during the growing season (May–September). We identified as important CH₄ sources floodplains (mean 1.55 ± 0.97 mg CH₄–C m^?2 h^?1) and domestic ruminants, which are mainly sheep in this area. Within the floodplain significant differences between investigated positions were detected, whereby only positions close-by the river or bayous emitted large amounts of CH₄ (mean up to 6.21 ± 1.83 mg CH₄–C m^?2 h^?1). Further CH₄ sources were sheepfolds (0.08–0.91 mg CH₄–C m^?2 h^?1) and pasture faeces (1.34 ± 0.22 mg CH₄–C g^?1 faeces dry weight), but they did not play a significant role for the CH₄ budget. In contrast, dung heaps were not a net source of CH₄ (0.0 ± 0.2 for an old and 0.0 ± 0.3 μg CH₄–C kg^?1 h^?1 for a new dung heap). Trace gas measurements along two landscape transects (volcano, hill slope) revealed expectedly a mean CH₄ uptake (volcano: 76.5 ± 4.3; hill: 28.3 ± 5.3 μg CH₄–C m^?2 h^?1), which is typical for the aerobic soils in this and other steppe ecosystems. The observed fluxes were rarely influenced by topography.The CH₄ emissions from the floodplain and the sheep were not compensated by the CH₄ oxidation of aerobic steppe soils and thus, this managed semi-arid grassland did not serve as a terrestrial sink, but as a source for this globally important greenhouse gas. The source strength amounted to 1.5–3.6 kg CH₄–C ha^?1 during the growing season, corresponding to 3.5–8.7 kg C ha^?1 yr^?1.     

Biogeochemical C and N cycles in urban soils

The percentage of urban population is projected to increase drastically. In 2030, 50.7 to 86.7% of the total population in Africa and Northern America may live in urban areas, respectively. The effects of the attendant increases in urban land uses on biogeochemical C and N cycles are, however, largely unknown. Biogeochemical cycles in urban ecosystems are altered directly and indirectly by human activities. Direct effects include changes in the biological, chemical and physical soil properties and processes in urban soils. Indirect effects of urban environments on biogeochemical cycles may be attributed to the introductions of exotic plant and animal species and atmospheric deposition of pollutants. Urbanization may also affect the regional and global atmospheric climate by the urban heat island and pollution island effect. On the other hand, urban soils have the potential to store large amounts of soil organic carbon (SOC) and, thus, contribute to mitigating increases in atmospheric CO(2) concentrations. However, the amount of SOC stored in urban soils is highly variable in space and time, and depends among others on soil parent material and land use. The SOC pool in 0.3-m depth may range between 16 and 232 Mg ha(-1), and between 15 and 285 Mg ha(-1) in 1-m depth. Thus, depending on the soil replaced or disturbed, urban soils may have higher or lower SOC pools, but very little is known. This review provides an overview of the biogeochemical cycling of C and N in urban soils, with a focus on the effects of urban land use and management on soil organic matter (SOM). In view of the increase in atmospheric CO(2) and reactive N concentrations as a result of urbanization, urban land use planning must also include strategies to sequester C in soil, and also enhance the N sink in urban soils and vegetation. This will strengthen soil ecological functions such as retention of nutrients, hazardous compounds and water, and also improve urban ecosystem services by promoting soil fertility.