Tentative reference values for some elements in broncho-alveolar lavage fluid.

The concentrations of Fe, Mn, Pb and Cr have been determined in broncho-alveolar lavage (BAL) fluid of 25 subjects without occupational or abnormal environmental exposure to metals, using the AAS method. The numerous factors which can interfere with the results in pre-analytical and in analytical phases are stressed. Metals concentrations in BAL are expressed in micrograms/l. They were not correlated with the volume of fluid recovered, the total cells, alveolar macrophages and erythrocytes. The results were not modified by stratification considering age and sex. Iron concentrations were higher than others, probably due to higher environmental exposure and partly to its essential role in humans. The diagnostic significance of element determination in BAL fluid and the relationship with exposure and lung load is discussed.     

Criteria for the definition of reference values for toxic metals.

Two types of selection are used to identify subjects who make up reference groups: 'a posteriori' selection starting from a large number of subjects who are then subsequently selected and 'a priori' selection wherein the group to be examined is defined on the basis of preestablished criteria. The main variability factors are biological and those depending on the modalities of selection of groups and determination of the analysis. The nature of the element is also particularly important, i.e. whether an essential element must be considered only a micropollutant or whether it should be considered essential and at the same time a micropollutant. In addition two other factors which play an important role are the temporo-spatial modifications induced by natural or anthropogenic phenomena which influence the modality and degree of exposure in man. Two criteria are generally used in the production of reference groups: exclusion/inclusion and partitioning criteria. While in clinical chemistry the health status represents an important exclusion factor, in the case of metals, the environmental conditions and the function of organs and apparatuses involved in the toxicokinetics of metals can be considered as main criteria. All the other variables such as sex, age, life-style are partitioning criteria and enable us to obtain reference values for more and more homogeneous subgroups.     

The ICOH and IUPAC international programme for establishing reference values of metals.

In cooperation with the ICOH Scientific Committee on the Toxicology of metals and IUPAC Commission on Toxicology, we have developed evaluation criteria for derivation of reference values for metal concentrations in human tissues and fluids. In a first attempt to illustrate how these criteria may be used, tentative reference values for mercury in human blood were derived. For persons who do not eat fish, a mean value of 10 mumol/1 (2 micrograms/1) was suggested. It was pointed out, however, that this value was based on information that did not meet the desired quality requirements, which, unfortunately were not met by any of the published reports.     

广东鸿沟山金银多金属矿区地质特征及成矿规律

鸿沟山金银多金属矿区处于北东向汕头—惠来深断裂带与北西向饶平—大埔大断裂交汇部位,晚侏罗世大北山火山盆地南缘,区内出露地层主要有上三叠统至下侏罗统头木冲组、银瓶山组碎屑岩,北西向断裂为主要控矿容矿构造,矿化与花岗闪长斑岩关系密切。矿(化)体呈脉状、似脉状产出。文章对矿区的地质特征、地球化学特征、矿(化)体特征及围岩蚀变、成矿规律进行了阐述和分析,通过综合研究,初步推断矿床成因属热液充填交代为主的脉状矿床,并提出了找矿方向。     

Assessment of reference values for mercury in urine: the results of an Italian polycentric study

The results of a polycentric study to assess the reference values of urinary mercury (U-Hg) in four Italian cities are presented. A total of 383 subjects were selected on the basis of standardised criteria by a questionnaire on personal habits, lifestyle, occupational or non-occupational exposure to Hg, medical history, number and area of dental amalgams. U-Hg was determined by hydride generation atomic absorption method (HG-AAS), with a detection limit of 0.5 microg/l and by flow injection (FI) inductively coupled plasma mass spectrometry (ICP-MS), with a detection limit of 0.03 microg/l. The median value of U-Hg, determined by HG-AAS, was 0.78 microg/g creatinine (0.75 for males and 0.83 for females), with 5 degrees and 95 degrees percentiles, respectively, of 0.17 and 3.66 microg/g creatinine. When determined by FI ICP-MS, the median value was 0.79 microg/g creatinine (0.77 for males and 0.79 for females) with 5 degrees and 95 degrees percentiles of, respectively, 0.12 and 5.02 microg/g creatinine. Among the independent variables, city of origin, area of dental amalgams, fish intake and tobacco smoking significantly influenced the U-Hg levels. The U-Hg reference values from this survey are lower than those from other recent investigations, probably due to characteristics and selection of the examined individuals and to the strict control of pre-analytical and analytical factors of variability.     

Selection of typical weather data (test reference years) for Subang,Malaysia

The paper discusses methods of selecting typical weather data and describes the selection of test reference years (TRYs) for Subang, Malaysia. The TRYs were selected using the Finkelstein–Schafer statistic, from 19 years of meteorological data recorded during the period 1980-98. Changing the weighting of the various meteorological variables (dry bulb temperature, solar radiation, relative humidity and wind speed) in the range appropriate for building performance studies had little effect on the selection, so it is recommended that equal weightings should be used unless there are particular reasons for using some other weighting. The replacement of relative humidity by moisture content had little effect on the selection.     

隧道监控量测回归分析浅析

监控量测是现代隧道建设不可或缺的一部分,通过将隧道围岩变形分三个时间阶段分析及围岩变形量与时间关系曲线的拟合,得到围岩各个时间阶段位移变形量求解方法,并结合实例给出求解过程,为准确判断围岩稳定性提供了理论指导。     

浅析城市污水处理厂建设的布局规划

简要分析了大型集中污水处理厂在控制水环境污染中发挥的重要作用,论述了污水处理厂建设发展趋势,进而探究了污水处理厂布局规划应考虑的主要因素,有利于处理后污水的就近利用。     

Urinary thallium: critical problems, reference values and preliminary results of an investigation in workers with suspected industrial exposure

Using a sensitive ETA ASS method, urinary thallium (Tl-U) has been measured in a group of non-exposed individuals and in two groups of workers with suspected industrial exposure. In non-exposed subjects (72 healthy males aged 41 +/- 11 years) the Tl-U mean value was 0.22 mu/l (range 0.05-0.61). Significantly higher values were found in two groups of workers (30 and 21 subjects) employed in two cement factories and two cast iron foundries (mean Tl-U value: 0.38 and 0.33 mu/l, respectively; range 0.06-1.2). Thallium has been determined in coal, raw materials and, in one factory, also in environmental samples, but no detectable levels were found. The analytical problems connected to urinary thallium determination and the preliminary results of biological monitoring in non-exposed individuals and in workers are discussed.     

云南北衙超大型金矿床控矿因素的重磁解释及探讨

北衙超大型金矿床属与喜马拉雅期正长斑岩有关的复合成因矿床,通过对北衙地区的地层、构造、岩浆岩的重磁解释及综合研究,对该矿床特殊的成矿环境进行了分析和探讨,认为其形成主要受岩体、构造、地层、古盆地4个因素控制,并预测红泥塘、炉坪村、金井山一带有较好的找矿远景。     

辽宁白云金矿区岩脉与成矿作用浅谈

白云金矿是辽宁省东部大型金矿床之一,矿区内岩脉发育,与成矿作用密切相关。结合对野外地表、坑道和钻孔的详细观察,初步理清各岩脉之间侵位先后顺序为辉长岩!花岗斑岩!石英斑岩!(矿体)!闪长玢岩!煌斑岩。利用岩脉探讨了区域构造特征,并结合岩脉本身的矿化信息探讨了岩脉与成矿关系。     

Trace element reference values in tissues from inhabitants of the European Community. II. Examples of strategy adopted and trace element analysis of blood, lymph nodes and cerebrospinal fluid of Italian subjects.

The EURO TERVIHT (Trace Element Reference Values in Human Tissues), recently initiated, aims to establish and compare trace metal reference values in inhabitants from the different EC countries. The project anticipates international cooperation of specialized chemical and toxicological laboratories in Western Europe. In order to overcome the well known and intolerable high fluctuation in published trace metal concentrations in body fluids and tissues, which are mostly due to poor analysis, this paper gives recommendations and strategies for approaching 'background' values measurement practised in the EURO TERVIHT. The focus of the paper is more on quality rather than on quantity of data with particular aspects: (i) well-described protocol for the selection/composition of reference groups (extended epidemiological data plus clinical status); (ii) numerous pre-analytical factors, among which are of paramount importance are ultraclean laboratory air, container material, storage conditions at -20 degrees C; (iii) statistical treatment of the data and the expression of the analytical results (use of refined statistical analysis such as the Lilliefors test to define the type of distribution, normal or log-normal). Results reported here concern the determination of trace elements in whole blood of more than 350 Italian subjects which allowed the proposal of 'reference values' for 12 elements. In lymph nodes and cerebrospinal (CSF) the degree of information acquired is only sufficient to suggest 'indicative' of 'informative' values.     

Regional input-output analysis,data and uncertainty

This paper addresses two major issues. The first is the introduction of uncertainty into the framework of classical deterministic regional input-output (I-O) analysis. Secondly, the role of the use of measurable flow data on the fundamental structure of the models is explored. The opening section uncovers an anomaly in the classical approach when flows between regions of final demand products, external exports and imports are neglected in comparison to the flows of internal intermediate inputs. Next, we introduce uncertainty into the analysis by extending an entropy formulation developed by Wilson, which itself evolved from the formalism established by Leontief-Strout (L-S). The main enhancements include (i) the introduction of regional output capacities to capture spillovers from regions operating close to capacity, (ii) the inclusion of flows of external imports and exports and (iii) the use of total measurable flows as input which are readily available from surveys, yielding as output not only the total flows of each sector between each pair of regions, but (optionally) the further disaggregation of these flows to include their final destination sector or their use as final demand. In fact, a key objective is to structurally account for the joint influence of technology, output capacities and transportation costs on the pattern of intermediate and final demand flows between regions. Further extensions of the approach lead to the generation of probabilistic supply functions as tools within a potential CGE analysis. This option requires the introduction of prices, permitting a profit constraint to replace the simple transport cost constraint of the earlier models.Received: August 2000 / Accepted: April 2003     

河北隆化县金银铅锌矿产分布规律及找矿前景初探

隆化县地处华北地台北缘中段,地层发育,构造活动期次多,岩浆岩活动强烈,各类矿产丰富,属承德地区有色金属矿产成矿聚集区之一.其中金、银、铅、锌等矿产在空间、时间分布和矿物组合等方面,有明显的规律性.但迄今为止,未能形成大的矿产地.文章根据该区成矿条件,筛选了部分成矿有利地段,可作为下一步找矿工作的重点.     

Sustainable regulatory systems: laws, resources, and values

Regulators frequently face difficult economic trade-offs in their decision-making. They must know how to assess the effects of policies on stakeholders under conditions of imperfect information. Part of the art of regulation revolves around understanding the linkages between choice of market structure, design of regulatory rules, and institutional requirements. In addition, different aspects of sector performance will be prioritized depending on the nation's level of development. Three factors determine the effectiveness of independent regulatory commissions during periods of change.

1. Resources available to the organization are generally determined by the legal instrument that brought the agency into existence. Budgets require funding mechanisms and procedures promoting accountability. Resource levels and resource mix (such as the percentage of highly motivated professionals) determine the range of activities suitable for the organization.

2. The legal mandate is interpreted by the courts. Since the law itself is often the product of political compromise, initial legislation may be inadequate for the effective performance of agency duties. Agency initiatives can precede formal legislative revisions, but these are likely to be challenged by some stakeholders.

3. The values or principles supporting the agency are derived from the national culture and a shared political vision. At the birth of the agency, leaders and key professional staff may not have reached consensus regarding priorities. Agreement on fundamental principles is essential if the agency is to develop a consistent set of policies.

Extinction of lithium fires: Thermodynamic computations and experimental data from literature

As described in the literature, various substances have been tried as extinguishants for metallic lithium fires. For many of these substances, the equilibrium temperature was computed from the reaction of the substance with hot (1040°C) lithium. For some of these substances, the computed equilibrium temperature was sufficiently low that the substances could be considered good extinguishants, and this was generally borne out by literature data. Some of the more promising substances for use as lithium fire extinguishants are silicon carbide (SiC), magnesium oxide (MgO), liquid argon, and boron nitride. Compounds found both by computation and in the literature to enhance combustion include carbon dioxide, Teflon^TM, Halon 1211, and carbon tetrachloride.     

青海瓦勒根金矿床地质特征及矿床成因

瓦勒根金矿床位于同德—泽库成矿带东段,区域上与甘肃省境内的夏河—岷县成矿带相接,与枣子沟、寨上、大桥、阳山金矿床具有等距分布的规律,显示出巨大的找矿潜力。文章针对瓦勒根金矿床进行了地质特征及矿床成因分析,研究表明:矿床严格受控于近东西向和北西向层间破碎带、裂隙,发育硅化、褐铁矿化、绢云母化,伴随辉锑矿化发育;中—下三叠统隆务河组第三岩性段(T_(1-2)l~3)泥质细碎屑岩可能为区域内金矿床的主要矿源层;矿床与侵位于近东西向断裂破碎带中的石英斑岩(脉)有密切联系,岩体(脉)含量较高的Au介于4.9×10~(-9)～32.6×10~(-9)之间,最高达300×10~(-9),因此,石英斑岩(脉)可能为矿区的另一矿源层;矿床与枣子沟、寨上、大桥、阳山金矿床具有一致的大地构造环境背景,成矿地质背景条件类似,其成因类似,均属于微细粒浸染型金矿床。     

水利工程开发建设项目水土保持措施浅析

分析了水利工程开发建设项目水土流失的特点,阐述了水利工程施工临时占地防治区、弃渣场防治区、料场防治区的水土保持工程措施,以及弃渣场和料场防治区的植物措施,最后提出了水土保持工程组织保障措施,为水利工程开发建设项目实施水土保持提供指导。     

Nanomaterials for environmental studies: Classification, reference material issues, and strategies for physico-chemical characterisation

NanoImpactNet is a European Commission Framework Programme 7 (FP7) funded project that provides a forum for the discussion of current opinions on nanomaterials in relation to human and environmental issues. In September 2008, in Zurich, a NanoImpactNet environmental workshop focused on three key questions:

1.

What properties should be characterised for nanomaterials used in environmental and ecotoxicology studies?

2.

What reference materials should be developed for use in environmental and ecotoxicological studies?

3.

Is it possible to group different nanomaterials into categories for consideration in environmental studies?

Such questions have been, at least partially, addressed by other projects/workshops especially in relation to human health effects. Such projects provide a useful basis on which this workshop was based, but in this particular case these questions were reformulated in order to focus specifically on environmental studies. The workshop participants, through a series of discussion and reflection sessions, generated the conclusions listed below.The physicochemical characterisation information identified as important for environmental studies included measures of aggregation/agglomeration/dispersability, size, dissolution (solubility), surface area, surface charge, surface chemistry/composition, with the assumption that chemical composition would already be known.There is a need to have test materials for ecotoxicology, and several substances are potentially useful, including TiO₂ nanoparticles, polystyrene beads labelled with fluorescent dyes, and silver nanoparticles. Some of these test materials could then be developed into certified reference materials over time.No clear consensus was reached regarding the classification of nanomaterials into categories to aid environmental studies, except that a chemistry-based classification system was a reasonable starting point, with some modifications. It was suggested, that additional work may be required to derive criteria that can be used to generate such categories, that would also include aspects of the material structure and physical behaviour.