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.     

Estimation of the environmental risk posed by landfills using chemical, microbiological and ecotoxicological testing of leachates

The leachates from 22 municipal solid waste (MSW) landfill sites in Southern Poland were characterized by evaluation of chemical, microbiological and ecotoxicological parameters. Chemical analyses were mainly focused on the identification of the priority hazardous substances according to Directive on Priority Substances, 2008/105/EC (a daughter directive of the WFD) in leachates. As showed, only five substances (Cd, Hg, hexachlorobutadiene, pentachlorobenzene and PAHs) were detected in the leachates. The compounds tested were absent or present at very low concentrations. Among them, only PAHs were found in all samples in the range from 0.057 to 77.2 μg L⁻¹. The leachates were contaminated with bacteria, including aerobic, psychrophilic and mesophilic bacteria, coliform and fecal coliforms, and spore-forming-bacteria, including Clostridium perfringens, and with filamentous fungi. From the analysis of specific microorganism groups (indicators of environmental pollution by pathogenic or opportunistic pathogenic organisms) it can be concluded that the landfill leachates showed sanitary and epidemiological hazard. In the ecotoxicological study, a battery of tests comprised of 5 bioassays, i.e. Microtox®, Spirotox, Rotoxkit F™, Thamnotoxkit F™ and Daphtoxkit F™ magna was applied. The leachate samples were classified as toxic in 13.6%, highly toxic in 54.6% and very highly toxic in 31.8%. The Spirotox test was the most sensitive bioassay used. The percentage of class weight score was very high - above 60%; these samples could definitely be considered seriously hazardous and acutely toxic to the fauna and microflora.No correlations were found between the toxicity values and chemical parameters. The toxicity of leachate samples cannot be explained by low levels of the priority pollutants. It seems that other kinds of xenobiotics present in the samples at subacute levels gave the high aggregate toxic effect.The chemical, ecotoxicological and microbiological parameters of the landfill leachates should be analyzed together to assess the environmental risk posed by landfill emissions.     

Development of a hybrid microbial fuel cell (MFC) and fuel cell (FC) system for improved cathodic efficiency and sustainability: the M2FC reactor

In an effort to improve the efficiency and sustainability of microbial fuel cell (MFC) technology, a novel MFC reactor, the M2FC, was constructed by combining a ferric-based MFC with a ferrous-based fuel cell (FC). In this M2FC reactor, ferric ion, the catholyte in the MFC component, is regenerated by the FC system with the generation of additional electricity. When the MFC component was operated separately, the electricity generation was maintained for only 98 h due to the depletion of ferric ion in the catholyte. In combination with the fuel cell, however, the production of power was sustained because ferric ion was continually replenished from ferrous ion in the FC component. Moreover, the regeneration process of ferric ion by the FC produced additional energy. The M2FC reactor yielded a power density of up to 2 W m⁻² (or time-averaged value of approximately 650 mW m⁻²), density up to 20 times (or approximately six times based on time-averaged value) higher than the corresponding MFC system.     

Comparing the sensitivity of soil invertebrates to pesticides with that of Eisenia fetida

The sole routine testing of the standard earthworm Eisenia fetida for the terrestrial risk assessment of pesticides has been under much debate since other soil invertebrates may be more sensitive than this standard test species. However, the very low availability of laboratory toxicity data for taxa other than E. fetida has greatly hampered sensitivity comparisons. In the present study, the relative tolerance (T_rel) approach was used to enable comparing toxicity thresholds obtained from the US-EPA ECOTOX database, for main terrestrial taxonomic groups and pesticidal types of action (insecticides, fungicides, herbicides, and other) separately. Analyses confirmed previously reported lower and higher sensitivity of collembolans to fungicides and insecticides, respectively. However, various other discrepancies in susceptibility relative to E. fetida were encountered as indicated by species sensitivity distributions and/or calculated 95% confidence intervals of T_rel values. Arachnids and isopods were found to be more sensitive to insecticides, and nematodes to fungicides, as compared to E. fetida. Implications of study findings for the terrestrial risk assessment of pesticides are discussed.     

2种再生水深度处理工艺对有毒有机污染物去除效果的评价研究

采用固相萃取(SPE)技术和气相色谱/质谱联用(GC/MS)的方法对2个再生水厂的进水和不同深度处理工艺出水中的有毒有机污染物进行了定性和定量分析,讨论了这2种不同再生水深度处理工艺对有毒有机污染物的去除效果.结果表明,厌氧/缺氧/好氧(A2/O)+连续微滤技术(CMF)+加氯消毒处理工艺和水解酸化+膜生物反应器(MB...     

大宝山矿区水体和沉积物中重金属的污染评价

分别于丰水期和枯水期对广东省大宝山矿区铁龙拦泥坝至凉桥河段水体中溶解态的重金属进行了调查,应用EPA推荐的健康风险评价模型发现,水体中非致癌物通过饮水途径所导致平均个人年风险排列顺序是Cu〉Pb〉Zn,最大值的平均个人年风险在丰水期和枯水期的平均值分别是2.14×10-7 a-1和4.13×10-7 a-1,小于国际防辐射委员会（ICRP）推荐的最大可接受平均个人年风险5.0×10-5a-1。致癌物Cd的平均个人年风险在丰水期和枯水期的平均值分别是3.52×10-4 a-1和4.53×10-4 a-1,大于ICRP推荐的最大可接受值,同时也大于非致癌物3～4个数量级。另外,通过对枯水期沉积物的重金属总量分析,发现凉桥槽对坑支流受水体pH的影响,导致其沉积物重金属的浓度最高。根据Long和Macdonald利用生物效应数据库法建立的沉积物质量基准,发现除冷水泾外,其他采样点的平均效应中值指数（mERMQ）值都大于1.5,可见沉积物中的重金属会对当地底栖生物产生毒害作用。     

退化河流滨岸带生态系统的修复及评价研究进展

退化河流滨岸带生态系统修复及其评价是目前国内外学者研究的热点,也是修复生态学、流域生态学等学科研究的重要内容之一。河流滨岸带生态修复工作的开展必须建立在掌握滨岸带结构及其生态功能的基础上。河流滨岸带生态系统退化成因和驱动机制研究是进行滨岸带生态修复工作的前提;生态系统修复是滨岸带研究的重点和关键,必须遵循自然法则,以修复生态功能为最终目标;河流滨岸带生态系统的修复过程和效果应该建立适宜的评价方法和管理策略来确定。加强河流滨岸带退化机制的理论研究及3S技术的应用,从景观和流域尺度开展滨岸带生态修复的研究和实践工作,着重进行平原河网地区河流滨岸带生态修复的研究和实践工作等将是中国今后相关研究的重点。     

An evaluation of legislative measures on electrical and electronic waste in the People's Republic of China

With the increasing number of recycling mishaps in connection with waste electronic and electrical equipment (WEEE) in the People's Republic of China, it is imperative that the handling and recycling of WEEE be sufficiently regulated in China. Regulations covering three major issues, namely, take-back issues, controls on hazardous substances in WEEE and the assurance of good environmental management in WEEE plants, were promulgated between 2006 and 2008. The evaluation in this country report shows that few of these regulatory measures have performed satisfactorily in terms of enforcement, of public acceptance and of environmental concerns. In brief, the take-back requirements and the associated financial responsibilities are only vaguely defined; the control on hazardous substances and the so-called "environmental expiry date" requirements cannot be properly enforced, and the resources needed to ensure the satisfactory enforcement of the environmental abatement and pollution control requirements in WEEE plants are overwhelming. In addition, the use of a "multiple enforcement body" approach to the control of hazardous substances in WEEE is an indication that the Chinese government lacks the determination to properly enforce the relevant legal requirements.     

Environmental assessment of garden waste management in the Municipality of Aarhus, Denmark

An environmental assessment of six scenarios for handling of garden waste in the Municipality of Aarhus (Denmark) was performed from a life cycle perspective by means of the LCA-model EASEWASTE. In the first (baseline) scenario, the current garden waste management system based on windrow composting was assessed, while in the other five scenarios alternative solutions including incineration and home composting of fractions of the garden waste were evaluated. The environmental profile (normalised to Person Equivalent, PE) of the current garden waste management in Aarhus is in the order of −6 to 8 mPE Mg⁻¹ ww for the non-toxic categories and up to 100 mPE Mg⁻¹ ww for the toxic categories. The potential impacts on non-toxic categories are much smaller than what is found for other fractions of municipal solid waste. Incineration (up to 35% of the garden waste) and home composting (up to 18% of the garden waste) seem from an environmental point of view suitable for diverting waste away from the composting facility in order to increase its capacity. In particular the incineration of woody parts of the garden waste improved the environmental profile of the garden waste management significantly.     

Engineered nanomaterials in rivers--exposure scenarios for Switzerland at high spatial and temporal resolution

Probabilistic material flow analysis and graph theory were combined to calculate predicted environmental concentrations (PECs) of engineered nanomaterials (ENMs) in Swiss rivers: 543 river sections were used to assess the geographical variability of nano-TiO₂, nano-ZnO and nano-Ag, and flow measurements over a 20-year period at 21 locations served to evaluate temporal variation. A conservative scenario assuming no ENM removal and an optimistic scenario covering complete ENM transformation/deposition were considered. ENM concentrations varied by a factor 5 due to uncertain ENM emissions (15%-85% quantiles of ENM emissions) and up to a factor of 10 due to temporal river flow variations (15%-85% quantiles of flow). The results indicate highly variable local PECs and a location- and time-dependent risk evaluation. Nano-TiO₂ median PECs ranged from 11 to 1′623 ng L⁻¹ (conservative scenario) and from 2 to 1′618 ng L⁻¹ (optimistic scenario). The equivalent values for nano-ZnO and nano-Ag were by factors of 14 and 240 smaller.