The measurement of intracellular zinc in human intestinal mucosa using x-ray microanalysis

The zinc content of intestinal epithelial cells in human jejunum and ileum has been measured using X-ray microanalysis. The range of values was wide, the highest being found in stem cells and enterocytes. Significant differences were found in jejunum from gastric carcinoma patients and ileum from Crohn's disease patients compared with patients with non malignant, non inflammatory disease.     

现有建筑物的环境评价工具

许多国家已经采用了在建筑物管理中可以支持决策的环境评价方法.建筑和建造研究与革新国际理事会100工作小组(GIB W100)一直在考察几种这样的环境评价方法的实施.本文介绍的澳大利亚、瑞典、挪威与加拿大的评价工具是为评定现有建筑物设计的.法国与日本的做法也包括了现有建筑物的评价工具.本文简要地讨信纸了每种方法的优缺点.大多数评价方法是把自我评价与一些外部证明(通常与认证有关)结合起来,这就允许各方更加接近址接与评价方法有关的工作并同时确保评价的质量.越来越多的国家正在发展与实施建筑物环境评价方法和评价工具.最近的方法强调了环境问题,不仅是在各种设计阶段的环境问题,而且还有建筑施工期间的环境问题.     

Polychlorinated biphenyls in polysulfide sealants--occurrence and emission from a landfill station

Approximately 80,000 kg polysulfide sealant containing 10,000-18,000 kg polychlorinated biphenyls (PCB) was deposited at a Swedish municipal landfill station during 1965-1973. Investigations during 1994 showed that soil layers underneath the landfill had concentration of PCB not alarmingly high. The concentration of PCB congeners in ground water samples was elevated 4-750 times compared to a reference sample. Based on samples of ground water, leachate water, and flux chambers measuring evaporation of PCB from the landfill surface, the emission of PCB was estimated to be 1 g sigmaPCB/yr. This very low rate was attributed to the high sorptive capacity of the sealant. Compared to a reference site, the evaporation flux was elevated for the most volatile congeners, but factors 20-1400 lower than from another landfill which was contaminated with PCB in paper-pulp fibres.     

现有建筑物的环境评价工具

许多国家已经采用了在建筑物管理中可以支持决策的环境评价方法.建筑和建造研究与革新国际理事会100工作小组(GIB W100)一直在考察几种这样的环境评价方法的实施.本文介绍的澳大利亚、瑞典、挪威与加拿大的评价工具是为评定现有建筑物设计的.法国与日本的做法也包括了现有建筑物的评价工具.本文简要地讨信纸了每种方法的优缺点.大多数评价方法是把自我评价与一些外部证明(通常与认证有关)结合起来,这就允许各方更加接近址接与评价方法有关的工作并同时确保评价的质量.越来越多的国家正在发展与实施建筑物环境评价方法和评价工具.最近的方法强调了环境问题,不仅是在各种设计阶段的环境问题,而且还有建筑施工期间的环境问题.     

Compound dependence of the relationship log Kow and log BCFL

Linear relatinships between log bioconcentration factor (BCF) and log K^ow for a variety of compounds have been reported many times in the literature. Analysis of the thermodynamics of the two partition processes has, however, shown that they are not analogous and that linear relationships can be expected to have different slopes for structurally unrelated compounds. In this study a set of literature lipid normalized BCF (BCF_L) values of chlorbenzenes (CBs) for rainbow trout and polycyclic aromatic hydrocarbons (PAHs) forDaphnia was put together with literature K_ow values. The slopes of the regression lines for log BCF_L versus log K_ow for the two groups of compounds proved to differ significantly in a statistical test using analysis of variance (ANOVA). The difference, which is of significance for estimates of BCFs in environmental modelling of these types of compounds, is explained by the differences in chemical structure of the two groups of compounds.     

Assessing PAH and PCB emissions from the relocation of harbour sediments using equilibrium passive samplers

Large-scale dredging of contaminated sediments is taking place in the harbor of Oslo, Norway. The dredged sediment masses are transferred into a confined aquatic disposal facility (CAD) in a natural 70-m deep basin within the Oslofjord. Currently there is no established method to determine how much dissolved contaminants are released during relocation and deposition of these sediments. For this reason we tested the use of equilibrium passive samplers consisting of 55 microm thin polyoxymethylene (POM-55) for studying the release of freely dissolved and thus bioavailable PAHs and PCBs at the disposal site, and found this to be a suitable method. In order to use POM-55 for monitoring PCBs, it was necessary to measure their POM-55/water partition coefficients, which was also presented as part of this study. Elevated turbidity (average 4.1 mg l(-1)) was observed at one side of the basin where no natural sill exists. Analysis of POM-55 at this location before and after deposition revealed that there was an increase in freely dissolved concentrations (C(W,free)) during deposition by a factor 37.5 for PAHs and a factor of 2.9 for PCBs. In addition, during deposition phenanthrene-to-anthracene aqueous concentration ratios at this location (values of 3-4) were more similar to those of the deposited sediments (approximately 2) than to those of the CAD water prior to deposition (approximately 14). This was not observed for the other locations where a natural sill exists at approximately 30 m water depth. The POM-55 equilibrium passive samplers are here shown to be useful tools for measuring and understanding the dynamics involved in the release of dissolved contaminants during sediment relocation.     

Pericentric inversion of the Y chromosome and prenatal diagnosis

Pericentric inversion of the human Y chromosome has been estimated to occur with a frequency of 1–2 per thousand in various populations, and the results of this study, derived from over 12 000 prenatal diagnosis cases, is 1.15 per 1000. In these cases, it was concluded that there was no clinical significance because the fathers and male fetuses had the same pericentric inversion. Chromosome analysis of the father is advisable to determine whether or not the inversion is familial in order to be able to provide genetic counselling.     

Effects of increased sea water concentrations of CO2 on growth of the bivalve Mytilus edulis L

It has been proposed that emission of anthropogenic carbon dioxide to the atmosphere will lead to increased concentrations of CO(2) in sea water corresponding to a decrease of pH of several tenths of pH units. An experiment was performed to test the effects of increased sea water concentrations of CO(2) on shell growth of the blue mussel Mytilus edulis. The experiment was performed in aquaria continuously flushed with sea water spiked with CO(2) to provide five different levels of pH between 6.7 and control sea water with a pH of 8.1. The shell length of the mussels was measured at the start and end of the 44 days experimental period. No mortality was observed during the first 23 days of the experiment. The growth increment in mm was much larger for small mussels than for large mussels, but relative growth profile as function of pH was more similar in the two size groups; observed differences may be random variation between samples. The experiments showed that CO(2) induced reduction of pH affects the growth of M. edulis negatively. There was a strong and statistically significant decrease in growth at the lowest pH values, with virtually no growth at pH = 6.7 and reduced growth at pH = 7.1. The effect seems to set in between pH 7.4 and 7.1; at mean pH levels 7.4 and 7.6 the growth increments were not significantly different from growth at normal pH 8.1.