UV Spectroscopic Monitoring of Vaporized Monoaromatic Hydrocarbons from Petroleum-Contaminated Soils

Fast and simple systems using ultraviolet (UV) absorbance were examined for on-line monitoring of monoaromatic hydrocarbons from petroleum-contaminated soils in this research. Since soil particles hinder the UV light transmittance, the absorbance measurement of vaporized monoaromatic hydrocarbons in soil gas extracted from petroleum-contaminated soils was proposed. In the fixed system that exhibited higher sensitivity than the portable one, the absorbance intensity of benzene, toluene, ethylbenzene, and xylene increased in proportion to the concentration of the contaminants. The portable system, however, was suitable for screening purpose, while it exhibited faster response. There was no interference from water, which helps the applicability of the proposed systems to the actual fields.     

Little Egrets (Egretta Garzetta) and Trace-Metal Contamination in Wetlands of China

The rapidly developing Asian countries may face threatening environmental contamination, that however remains largely unassessed. We studied persistent trace elements in three wetlands, Poyang Lake, relatively unpolluted, and Tai Lake, and Pearl River Delta, selected as hotspots of pollution in Central China. We adopted as indicator the Little Egret, a widespread colonial waterbird, and during 1999 and 2000 we collected and analysed the same samples as for a parallel study we conducted in Pakistan, e.g. eggs, body feathers of chicks, prey spontaneously regurgitated by the chicks, and sediments at the areas most used by foraging egrets. The levels of trace-metals at our three study areas were similar, or within the range, of those found in the few other studies for East Asia, with few exceptions. The concentrations of the various elements were below the threshold that may affect the survival or reproduction of the birds, and even the highest concentrations relative to background, i.e. Se in eggs, and Hg in feathers at Pearl Delta, do not pose toxic hazards. In sediments, the levels of trace elements were lower than the critical levels assumed for contaminated soil, except for alarming high levels of As at Poyang. These results do not confirm our expectation, that Poyang was relatively uncontaminated, while Tai and Pearl were polluted. Although trace metal concentration differed significantly among the three study areas, these differences were minor and were not consistent among elements and samples. The bioaccumulation ratios from sediments through prey, feather and egg, were consistent with our previous findings for Pakistan. Only Hg exhibited high bioaccumulation, while Se and Zn had low accumulation, and the other elements no accumulation. This reasserts that feathers of predators such as egrets, may be more sensitive indicators of environmental contamination for the elements subject to bioaccumulation, whereas the sediments or the organisms low in the food chain are better indicators for the other elements.     

基于复合生态系统理论的长沙湘江滨水区景观资源评价与优化

近年来,随着我国经济的飞速发展、社会经济的转型,以及人们环境意识的提高,滨水区开发已成为我国城市开发建设的热点。城市滨水区景观规划设计研究对于合理、充分利用城市滨水区景观资源,塑造特色鲜明的城市形象,提高城市生态环境质量,促进城市滨水区开发有着重要意义。从复合生态系统理论的角度,在湘江滨水区景观资源调查、景观资源分类的基础上,运用灰色聚类法对湘江滨水区景观资源进行定量评价,提出景观资源优化思路,探讨滨水区景观规划设计的途径。认为现代城市大规模滨水区更新改造和开发大背景下的城市滨水区景观规划设计,应尊重城市地域性特点、文化内涵和风土人情,并与传统的滨水活动有机结合,保护和突出城市历史格局和风貌特色。     

Effective communication about complex environmental issues: Perceived quality of information about carbon dioxide capture and storage (CCS) depends on stakeholder collaboration

This experimental research addresses the effectiveness of communication about complex environmental issues, depending on whether the same information is provided by multiple collaborating or by individual organizations (i.e., stakeholders). The information provided pertains to carbon dioxide capture and storage (CCS) technology, as an example of a complex environmental issue. In Studies 1 (N = 75) and 2 (N = 66) we found that participants perceived factual information from collaborating stakeholders to be of higher quality than when the same information was provided by individual stakeholders. As predicted, the expectation of diverse perspectives being represented in the collaborative information mediated this effect. In addition, in Study 3 (N = 79) the perceived dissimilarity of collaborating stakeholders was shown to be an important precondition for the collaboration effect observed in Studies 1 and 2. Finally, these studies indicate that occasional collaboration between different stakeholders does not necessarily harm the perceived credibility of each individual stakeholder.     

沼气农业复合生态系统能值分析

以沼气为纽带的农业综合利用系统对农村和偏远地区可持续发展具有重要意义。本文基于能值流图和指标体系,构建了沼气农业复合生态系统的综合评价框架,并以国家沼气农业示范区广西恭城县为案例,分析养殖-沼气-种植"三位一体"典型沼气农业复合系统的能值投入产出量及其结构,利用能值系统结构功能指标对该系统进行经济生态多元分析,评估其投资率、产出率、环境压力以及可持续性等系统综合表现,并与国内外其他农业系统进行比较分析。系统投入结果表明,恭城县沼气农业复合系统总投入中人类经济反馈在系统中所占比例最大,可更新环境资源次之,其中又以肥料、农药和劳工与管理的投入最大;系统产出表明,目前仍以种植业和养殖业为主导,水产业相对薄弱,而新兴的沼气产业因其低耗高产的特点,发展势头良好;而能值系统结构功能指标表明该农业系统整体具有环境负荷低、产出效率高、可持续性强等优势。依照能值分析各项结果,本文对沼气农业系统优化配置和进一步推广应用提出了参考建议。     

Attitudes of rural population in emergency exposure situations

People growing crops in kitchen gardens eat locally self-produced food and are the subject of growing attention as the potential for a more sustainable development. A survey was carried out in two provinces in northern Italy to gather information on the consumption of local horticultural products, peoples’ expectations of authorities in the case of a nuclear accident and peoples’ behaviour in the absence of official information. Results show that up to 70% of the owners of kitchen gardens possess diets comprised of more than 60% of self-produced vegetables and can be regarded as particular groups of population. In the case of a dispersion of radioactive material, the local population would take advantage of official information on preventive measures to protect farms and local crops from contamination. Results of the survey show differences in the attitude of the population due to age, gender and past experience.     

Policy and Science Implications of the Framing and Qualities of Uncertainty in Risks: Toxic and Beneficial Fish from the Baltic Sea

Policy and research issues in the framing and qualities of uncertainties in risks are analyzed, based on the assessments of dioxin-like compounds (DLCs) and other ingredients in Baltic Sea fish, a high-profile case of governance. Risks are framed broadly, to then focus on dioxins and beneficial fatty acids, fish consumption, human health, and science-management links. Hierarchies of uncertainty (data, model, decision rule, and epistemic) and ambiguity (of values) are used to identify issues of scientific and policy contestation and opportunities for resolving them. The associated complexity of risks is illustrated by risk–benefit analyses of fish consumption and by evaluations of guideline values, highlighting value contents and policy factors in presumably scientific decision criteria, and arguments used in multi-dimensional risk and benefit comparisons. These comparisons pose challenges to narrow assessments centered, for e.g., on toxicants or on food benefits, and to more many-sided and balanced risk communication and management. It is shown that structured and contextualized treatment of uncertainties and ambiguities in a reflexive approach can inform balances between wide and narrow focus, detail and generality, and evidence and precaution.     

Increased Bioavailability of Mercury in the Lagoons of Lomé, Togo: The Possible Role of Dredging

Surface sediments of the lagoons of Lomé, Togo, were analyzed for mercury, methylmercury, and trace elements. Concentrations were greater than typical for natural lagoon sediments, and with greater variability within the Eastern lagoon compared to the Western one. The Eastern lagoon is larger and has been dredged in the past, while the Western lagoon, which also receives major waste inputs, has not been dredged and shows less tidal flushing. Accordingly, one naturally believes that the Eastern lagoon is cleaner and probably safe to use due to its natural resources, including fishes to eat. Unexpectedly, we describe here that mercury methylation was greater in the Eastern lagoon, indicating increased bioavailability of mercury, as probably facilitated by past dredging that decreased solid-phase retention of inorganic mercury. Urbanization has historically been more developed in the southern part of the lagoons, which is still reflected in contamination levels of sediment despite dredging, probably because sources of contamination are still more important there today. Such urban contamination emphasizes the need to regulate waste discharges and possible airborne contamination in growing cities of developing countries, and implements environmental and public health monitoring, especially in relation to misbelieves systematically associated with the cleansing effect of dredging activity.     

Adsorption of As(III) on chitosan-Fe-crosslinked complex (Ch-Fe)

It was reported the adsorption of As(III) on the surface of the chitosan-Fe-crosslinked complex. Theoretical correlation of the experimental equilibrium adsorption data for As(III)/Ch-Fe system is best explained by the non-linearized form Langmuir-Freundlich isotherm model. At optimum conditions, pH 9.0, the maximum adsorption capacity, calculated using the Langmuir-Freundlich isotherm model was 13.4 mg g⁻¹. The adsorption kinetics of As(III) onto Ch-Fe are described by the pseudo-first-order kinetic equation. The results of the Mössbauer spectroscopy showed that there is no redox process on the surface of the adsorbent.     

基于产业链的区域环境污染物排放的产业贡献

区域经济增长与环境质量之间的关系研究是目前学者们探讨的重要学术议题之一.其中较多的是对EKC曲线的验证,近几年部分学者从国民经济各部门中的产业自身特征、产业结构、技术进步、FDI效应等方面考察产业发展对污染物排放的影响.然而以上研究议题中学者均没有讨论污染物的发生主体-各产业部门与排污的直接关系.故本文将从宏观尺度下的综合水平测度区域经济发展与环境质量关系、中观尺度下的产业属性特征与排污关系的研究视角转移至分析具体产业部门的污染物排放效应,同时将产业置于产业链的结构形式中,研究产业链上产业发展与污染物排放的关系.发现:第一,通过借助复杂网络思想的社区划分方法,将山东省39个产业部门分为3个社团.其中社团I主要由制造业部门组成,共有18个产业部门,社团II包括了15个部门,主要是第三产业,杜团III由6个产业部门组成且内部异质性高.第二,选择其中以制造业为主的社团I,并在社团I内识别出一条彼此间联系最为紧密的产业链,包括农林牧渔业、食品制造及烟草加工业、化学工业、纺织工业、服装皮革羽绒及其制品业、通用/专用设备制造业和交通运输设备制造业.以一种定量的方法获取了通过价值流传递而串在一起的产业链条.该产业链的经济规模、污染物规模在山东省均有重要地位.第三,采用岭回归分析方法,构建了6个制造业与产业链工业废水、固体废弃物排放的关系模型,6个制造业中对工业废水、固体废弃物排放相对贡献度最大的部门分别为服装皮革羽绒及其制品业、食品制造及烟草加工业.这是由于上游产业排污的链式传递效应与产业自身污染物排放效应的共同叠加作用.