Low dose effects and non-monotonic dose responses for endocrine active chemicals: Science to practice workshop: Workshop summary

A workshop was held in Berlin September 12–14th 2012 to assess the state of the science of the data supporting low dose effects and non-monotonic dose responses (“low dose hypothesis”) for chemicals with endocrine activity (endocrine disrupting chemicals or EDCs). This workshop consisted of lectures to present the current state of the science of EDC action and also the risk assessment process. These lectures were followed by breakout sessions to integrate scientists from various backgrounds to discuss in an open and unbiased manner the data supporting the “low dose hypothesis”. While no consensus was reached the robust discussions were helpful to inform both basic scientists and risk assessors on all the issues. There were a number of important ideas developed to help continue the discussion and improve communication over the next few years.     

Degradation of atrazine using solar driven fenton-like advanced oxidation processes

Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) was degraded using cobalt-peroximonosulfate (Co/PMS) advanced oxidation process (AOP). Three Co concentrations (0.00, 0.25 and 0.50 mM) and five peroximonosulfate (PMS) concentrations (0, 5, 8, 16 and 32 mM) were tested. Maximum degradation reached was 88% using dark Co/PMS in 126 minutes when 0.25 mM of cobalt and 32 mM of PMS were used. Complete atrazine degradation was achieved when the samples were irradiated by the sun under the same experimental conditions described. Tests for identification of intermediate products allowed identification and quantification of deethylatrazine in both dark and radiated conditions. Kinetic data for both processes was calculated fitting a pseudo-first order reaction rate approach to the experimental data. Having kinetic parameters enabled comparison between both conditions. It was found that the kinetic approach describes data behavior appropriately (R² ≥ 0.95). Pseudo-kinetic constants determined for both Co/PMS processes, show k value of 10^?4 for Co/PMS and a k value of 10^?3 for Co/PMS/ultraviolet (UV). This means, that, with the same Co/PMS concentrations, UV light increases the reaction rate by around one order of magnitude than performing the reaction under dark conditions.     

浙江省梅汛期洪涝灾情分析和预测

通过所构设的雨涝强度、雨涝影响面积等统计量来估计浙江省梅汛期的灾情,有较高的准确率,能估计出极端情况,为灾害评估工作提供了新的思路。     

Metals in biomass

Background, Aim and Scope

Metal ions generally share the ability/tendency of interacting with biological material by forming complexes, except possibly for the heavy alkali metals K, Rb and Cs. This is unrelated to the metals being either essential for sustaining life and its reproduction, apparently insignificant for biology, although perhaps undergoing bioconcentration or even being outright toxic, even at low admission levels. Yet, those different kinds of metal-biomass interactions should in some way depend on properties describing coordination chemistries of these very metals. Nevertheless, both ubiquitously essential metals and others sometimes used in biology should share these properties in numeric terms, since it can be anticipated that they will be distinguished from nonessential and/or toxic ones. These features noted above include bioconcentration, the involvement of metal ions such as Zn, Mg, Cu, Fe, etc. in biocatalysis as crucial components of metalloenzymes and the introduction of a certain set of essential metals common to (almost) all living beings (K, Mg, Mo, Mn, Fe, Cu and Zn), which occurred probably very early in biological evolution by ‘natural selection of the chemical elements’ (more exactly speaking, of the metallomes).

Materials and Methods

The approach is semiempirical and consists of three consecutive steps: 1) derivation of a regression equation which links complex stability data of different complexes containing the same metal ion to electrochemical data pertinent to the (replaced) ligands, thus describing properties of metal ions in complexes, 2) a graphical representation of the properties-two typical numbers c and x for each metal ion-in some map across the c/x-space, which additionally contains information about biological functions of these metal ions, i.e. whether they are essential in general (e.g. Mg, Mn, Zn) or, for a few organisms of various kinds (e.g. Cd, V), not essential (e.g. rare earth element ions) or even generally highly toxic (Hg, U). It is hypothesized that, if coordination properties of metals control their biological ‘feasibility’ in some way, this should show up in the mappings (one each for mono and bidentate-bonding ligands). 3) eventually, the regression equation produced in step 1) is inverted to calculate complex stabilities pertinent to biological systems: 3a) complex stabilities are mapped for ligands delivered to soil (-water) by green plants (e.g. citrate, malate) and fungi and, compared to their unlike selectivities and demands of metal use (photosynthesis taking place or not), 3b) the evolution of the metallome during late chemical evolution is reconstructed.

Results

These maps show some ‘window of essentiality’, a small, contrived range/area of c and x parameters in which essential metal ions gather almost exclusively. c and x thus control the possibility of a metal ion becoming essential by their influencing details of metal-substrate or (in cases of catalytic activities) metal-product interactions. Exceptions are not known to be involved in biocatalysis anyhow.

Discussion

Effects of ligands secreted, e.g. from tree roots or agaric mycelia to the soil on the respective modes (selectivities) of metal bioconcentration can be calculated by the equation giving complex stability constants, with obvious ramifications for a thorough, systematic interpretation of biomonitoring data. Eventually, alterations of C, N and P-compounds during chemical evolution are investigated — which converted CH₄ or CO₂, N₂ and other non-ligands to amino acids, etc., for example, with the latter behaving as efficient chelating ligands: Did they cause metal ions to accumulate in what was going to become biological matter and was there a selectivity, a positive bias in favour of nowessential metals (see above) in this process? Though there was no complete selectivity of this kind, neither a RNA world in which early ribozymes effected most of biocatalysis, nor a paleoatmosphere containing substantial amounts of CO could have paved the way to the present biochemistry and metallomes.

Conclusions

This way of reasoning provides a causal account for abundance distributions described earlier in the Biological System of Elements (BSE; Markert 1994, Fränzle &; Markert 2000, 2002). There is a pronounced change from chemical evolution, where but few transformations depended on metal ion catalysis to biology.

Recommendations and Perspectives

The application of this numerical approach can be used for modified, weighted evaluation of biomonitoring analytical data, likewise for the prediction of bioconcentration hazards due to a manifold of metal ions, including organometallic ones. This is relevant in ecotoxicology and biomonitoring. In combining apoproteins or peptides synthesized from scratch for purposes of catalysing certain transformations, the map and numerical approaches might prove useful for the selection of central ions which are even more efficient than the ‘natural’ ones, like for Co²⁺ in many Zn enzymes.

     

Water protection against pollution

Science-policy integration is one of the many complex challenges that scientific and policy-making communities are facing. It involves knowledge sharing and exchanges among a wide range of disciplines and actors. In many instances, the lack of proper communication and of a coordination mechanism leads to research outputs not being used or simply known by policy-makers, and to policy research needs not being communicated to the scientific communities in a timely fashion. This paper discusses the integration of scientific and technological progress into the policy-making and implementation process, with emphasis on water policies. It highlights the need and complexity of developing a knowledge-based approach which would enable to lead to an operational science-policy interface linked to WISE (Water Information System for Europe), including the newly developed WISERTD webportal (). The views expressed in this paper are purely those of the author and do not in any circumstances reflect an official position of the European Commission.     

阳极溶出伏安法快速测定地表水中镉

利用阳极溶出伏安法原理,采用PDV 6000型重金属快速分析仪测定地表水中的镉。在1.25μg/L~40.0μg/L范围内,质量浓度与阳极溶出峰电流和峰面积呈良好的线性关系,方法检出限为0.001 mg/L,水样平行测定的RSD为8.9%,加标回收率为80.5%~118%,与石墨炉原子吸收光谱法的测定结果基本一致。     

新疆煤矿项目竣工环保验收工作现状、问题及对策

新疆煤炭资源丰富,资源总量居全国各省之首,煤炭的大规模开采在带来经济效益的同时也带来一系列环境问题,如地表沉陷、水污染、煤矸石、噪声、矿区大气污染等诸多环境破坏和环境污染。为此,针对目前新疆煤矿竣工环境保护验收调查工作中存在的一些问题,提出解决问题的方法和思路。     

上海市浦东新区大气降水化学组分及其相关性分析

依据上海市浦东新区2010—2015年2个代表性采样点的142份监测数据,对降水中的化学组成及各组分间的相关性进行了分析。结果表明,监测期间单次降雨的pH值为3.85~6.09,平均值为5.09,属硫酸型/硝酸型复合污染酸雨。其中SO_4~(2-)和NO_3~-为主要离子,平均值分别为4.55和3.31 mg/L。通过SPSS统计分析得出,人类生活和生产过程以及海洋源是浦东新区大气降水化学组分的主要来源,但仍存在不同的区域特征。     

新形势下江苏省地表水自动监测站运行管理模式对策建议

简述了江苏省地表水自动监测站运行管理模式发展历程和现状,以及运行管理需求和存在的问题。分析了国内其他地区地表水自动监测站运行管理模式的优缺点。提出,下放部分站点管理权限,实现权责相对统一;试点社会化质控管理,强化省级监督管理能力;进一步完善制度建设,提高水站管理水平;探索新型管理模式,提高自动监测管理效能。     

方法标准验证实验数据中离群值的识别

对方法标准验证实验中测量数据进行合格性审核,对于后续方法精密度计算是一个重要环节。文献中识别离群值的Grubbs法、Dixon法等经典方法有时不能满足要求。探讨了用稳健统计法识别离群值的可行性。基于2套文献数据和XRF方法标准验证实验精密度测量数据,对Grubbs法、Dixon法、Mandel h检验法、质控指标法和稳健统计法(四分位法、迭代法、合格数据范围判定法)进行了比较。结果表明:稳健统计法可有效识别离群值。但四分位法存在过度"检出"现象。综合考虑多种方法识别结果有利于提高离群值判定结论的可靠性。对于个别难以判断的情形,可借助质控指标、技术要求以及数据是否剔除对实验室间标准偏差的影响进行取舍。