内蒙古乌梁素海入湖水质超标风险率分析

以内蒙古乌梁素海入流水体为研究对象,考虑湖泊水质的随机性和灰色不确定性,以灰色概率统计理论为基础,引入灰色-随机风险率方法,通过计算并分析2006年、2007年和2008年入湖断面各水质参数存在的超标风险性,反映不同水质参数的污染强度和污染历时的变化过程。结果表明,入湖水体总氮总磷浓度超标风险率呈现逐年上升的趋势;总氮浓度超过Ⅴ类标准值的上限风险率达96.4%,下限风险率达87.7%;总磷浓度超过Ⅴ类标准值的上限风险率达96.2%,下限风险率达86.9%;BOD5浓度超过Ⅴ类标准值的平均风险率达55%;COD浓度超过Ⅴ类标准值的平均风险率达85%。乌梁素海入湖水体污染程度已十分严重,源头水污染防治已刻不容缓。     

高投入菜地土壤磷素环境与农学阈值研究进展

维持适宜的土壤有效磷水平对保障蔬菜产量和水体安全具有十分重要的作用.而当前蔬菜种植体系磷肥投入的显著特征是高量、高频次,导致大量磷素累积在土壤中会增加磷素移动性从而引发高环境风险.一般认为菜地磷的环境阈值高于农田,但菜地的灌水和磷肥投入均远高于农田,因此磷流失程度仍高于农田.综合文献调研结果发现,我国不同地区的菜地土壤...     

Estimating the Risk of a Crop Epidemic From Coincident Spatio-temporal Processes

Fusarium Head Blight (FHB), or “scab,” is a very destructive disease that affects wheat crops. Recent research has resulted in accurate weather-driven models that estimate the probability of an FHB epidemic based on experiments. However, these predictions ignore two crucial aspects of FHB epidemics: (1) An epidemic is very unlikely to occur unless the plants are flowering, and (2) FHB spreads by its spores, resulting in spatial and temporal dependence in risk. We develop a new approach that combines existing weather-based probabilities with information on flowering dates from survey data, while simultaneously accounting for spatial and temporal dependence. Our model combines two space-time processes, one associated with pure weather-based FHB risks and the other associated with flowering date probabilities. To allow for scalability, we model spatiotemporal dependence via a process convolutions approach. Our sample-based approach produces a realistic assessment of areas that are persistently at high risk (where the probability of an epidemic is elevated for extended time periods), along with associated estimates of uncertainty. We conclude with the application of our approach to a case study from North Dakota.     

我国环境法基本制度探析

环境法基本制度是环境法体系的重要组成部分,对于我国环境法律规范的贯彻实施具有很重要的作用。环境法基本制度对环境污染的防治和环境资源的保护具有重大的指导意义,对法律关系的参加者直接具有约束力。对于环境法基本制度的研究不仅有利于环境法理论的完善和创新,而且能科学地为环境资源保护和污染防治的实践操作提供一个理论平台。但是目前对于环境法的基本制度的认识在我国立法和学术界之间尚未有统一的界定。试从我国现有的环境法基本制度的认识出发,结合中国市场经济和可持续发展的要求以及环境法本身的特点来探讨我国环境法的基本制度。     

啶氧菌酯环境归趋与生态风险研究进展

啶氧菌酯是一种对生态系统存在安全风险的甲氧基丙烯酸酯类杀菌剂,从环境归趋,生态毒理的角度出发,综述了啶氧菌酯在土壤、水中、农作物中的归趋,阐述了啶氧菌酯对蚯蚓、蜜蜂和水生非靶标生物急/慢性毒性,和对组织、酶活、蛋白、基因等方面的影响进行了归纳,并讨论了啶氧菌酯未来的生态毒理学研究方向。以期为进一步研究啶氧菌酯对非靶标生物毒性效应和作用机理,并制定相关策略以减少其生态风险提供依据。     

黄河中游侵蚀产沙环境要素临界与交互作用研究进展

目前黄河中游产沙的峰值区(多沙粗沙区)的范围已明确界定。但是，产沙峰值区的形成与地理环境要素(自然、人类活动)变化的响应机制是什么，影响产沙峰值区环境要素的综合作用和主导环境因素又是什么，还有待于深入研究。在前人研究的基础上，论述了黄河中游的环境因子和人类活动对流域侵蚀产沙影响研究的最新进展，根据研究中存在的问题及结合黄土高原正在开展的退耕还林的生物工程建设，指出加强流域产沙与环境要素临界特征与交互作用研究的重要性，揭示自然、人类活动在流域产沙的综合影响与交互作用，探讨在人类活动影响下植被的恢复前景与综合治理的减沙效益，是近期需要开展的主要研究方向。     

黄土高原侵蚀产沙的地貌临界

从地貌学的角度,较为深入地研究了黄土高原侵蚀产沙的几个临界问题:坡地系统的产沙临界、河道系统的产沙临界、以及地貌发育阶段的临界问题等,对地貌临界在黄土高原侵蚀产沙中应用作了进一步的探讨。结果表明,在黄土高原地貌发育阶段的不同临界范围内,其产沙量是不同的,因此,研究地貌临界不仅蕴涵着比较深刻的哲学和科学理论意义,而且具有一定的实践意义。     

Environmental Risk Assessment of Emerging Contaminants Using Degradation Data

The degradation behavior of an emerging contaminant is a key factor in its environmental risk assessment. Existing risk assessment methods based on EC degradation data commonly neglect the time-varying volatility of the degradation, the possible correlations in degradation between different ECs, and the estimation errors. To fill the gaps, this paper proposes an EC risk assessment framework based on the Wiener process. We first focus on degradation data from competitive experiments, which are adopted to evaluate a useful risk indicator, i.e., the bimolecular rate constant of a degradation reaction. A two-dimensional Wiener process model is developed to capture the degradation behaviors of the target EC and a reference contaminant in the experiment. Point and interval estimations of desired quantities, including the rate constant and the degradation half-life, are developed. We further extend the model to the multivariate case, which is applicable to waste water treatment where multiple ECs degrade in a mixed solution. A risk indicator for the mixed solution is proposed, based on which a minimal treatment time can be determined. Both point and interval estimation procedures of the risk indicator and the minimal treatment time are proposed. Two EC degradation datasets are used to demonstrate the proposed methodologies.   Supplementary materials accompanying this paper appear on-line.     

Synthesis: Thresholds in conservation and management

This paper is a brief overview of some of the key issues which have emerged from the preceding set of papers on ecological thresholds. These include:

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Whether threshold relationships are common and widespread.

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The potential for large variations in the use and application of the threshold concept to lead to adverse conservation outcomes, particularly when overly simplistic levels of vegetation cover are specified by policy makers and land managers.

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The inherent multi-variate nature of landscape processes and responses of individual species and assemblages that creates variability in datasets. This may lead to a limited ability to make accurate predictions from threshold relationships, even when those relationships are highly statistically significant.

We believe that although the threshold concept is an appealing one and there is some empirical evidence to support it in some landscapes, it is not free of problems and a concerted research effort on the topic is needed. This is particularly important if it is to have value for robustly underpinning applied landscape management practices without unintentionally having negative impacts on rates of species loss or the loss of particular species.     

我国Bt棉花商业化的环境影响与风险管理策略

Bt转基因棉花于1997年在我国商业化种植，到2006年种植面积已达棉花总面积的70％。环境影响监测表明，Bt棉花有效地控制了棉铃虫和红铃虫的发生和为害，但盲蝽蟓类害虫演化上升成为棉田的主要害虫。抗性分析显示，虽然棉铃虫自然种群对Bt棉花抗性基因频率没有明显的变化，但Bt棉花髙强度种植地区的棉铃虫耐受性正逐年提高，已成为影响Bt棉花持续利用的主要因素。基于Bt棉花环境风险和影响因子的综合分析，本文讨论了Bt棉花环境风险的管理策略。     

Environmental Risk Assessment for Pesticides in the Atmosphere; The Results of an International Workshop

The Health Council of the Netherlands organised an international workshop on the fate of pesticides in the atmosphere and possible approaches for their regulatory environmental risk assessment. Approximately forty experts discussed what is currently known about the atmospheric fate of pesticides and major gaps in our understanding were identified. They favoured a tiered approach for assessing the environmental risks of atmospheric dispersion of these chemicals. In the first tier a pesticide's potential for emission during application, as well as its volatilisation potential should be assessed. Estimates of the former should be based on the application method and the formulation, estimates of the latter on a compound's solubility in water, saturated vapour pressure and octanol/water partition coefficient. Where a pesticide's potential for becoming airborne exceeds critical values, it should be subjected to a more rigorous second tier evaluation which considers its toxicity to organisms in non-target areas. This evaluation can be achieved by calculating and comparing a predicted environmental concentration (PEC) and a predicted no-effect concentration (PNEC). By applying an extra uncertainty factor the PNEC can be provisionally derived from standard toxicity data that is already required for the registration of pesticides. Depending on the distance between the source and the reception area, the PEC can be estimated for remote areas using simple dispersion, trajectory type models and for nearby areas using common dispersion models and standard scenarios of pesticide use. A pesticide's atmospheric transport potential is based on factors such as its reaction rate with OH radicals. It should be used to discriminate between those compounds for which only the risks to nearby ecosystems have to be assessed, and those for which the risks to remote ecosystems also have to be determined. The participants were of the opinion that this approach is, in principle, scientifically feasible, although the remaining uncertainties are substantial. Further field and laboratory research is necessary to gain more reliable estimates of the physico-chemical properties of pesticides, to validate and improve environmental fate models and to validate the applicability of standard toxicity data. This will increase both the accuracy of and our confidence in the outcome of the risk assessment.     

黄河兰州段多环芳烃类有机污染物健康风险评价

近年来黄河兰州段的多环芳烃污染日渐严重。为研究黄河兰州段水体中多环芳烃类有机污染物对人体产生的潜在健康危害风险,根据黄河兰州段2004年11个采样点水质监测数据,应用美国环境保护局（USEPA）的健康风险评价方法对黄河兰州段多环芳烃类有机污染物通过饮水和皮肤接触途径进入人体的健康风险进行了初步评价。结果表明：黄河兰州段多环芳烃类有机污染物的非致癌风险指数值均小于1,其中萘的非致癌风险指数值在10^-3数量级,偏高于其他污染物。苯并（a）芘的致癌风险指数值在10^-4数量级以下。从位于西固八盘峡的1号采样点（S1）采集的水样中萘的非致癌风险指数值偏高。在所有采样点中,西固八盘峡的1号采样点（S1）污染较重,具有较高的健康风险。与国内其他地区相比,黄河兰州段萘的非致癌风险亦较高。常规的自来水处理工艺不能有效地去除源水中微量PAHs等有机污染物,因此地面水特别是饮用源水PAHs污染具有较大的健康风险。     

基于环境地球化学基线的农用地重金属累积特征及其潜在生态危害风险研究

为探明浙江东部某市周边农用地土壤重金属累积特征及潜在生态危害风险,系统采集研究区表土样品,测定重金属元素(As、Cd、Cr、Cu、Hg、Ni、Pb、Zn)和惰性元素(Li、Eu、Sc、Sm)含量。通过元素相关性分析,筛选出合适的标准因子,按标准化方法建立了研究区土壤重金属As、Cd、Cr、Cu、Hg、Ni、Pb和Zn环境地球化学基线,获得基线值分别为11.13、0.38、57.48、43.86、0.30、21.55、51.91和132.7mg·kg~(-1)。在应用单因子方法评价土壤重金属污染程度基础上,以环境地球化学基线值作为标准因子,采用富集因子方法判别因受人类活动影响的重金属污染点位,并对土壤重金属累积潜在的生态环境风险进行了评价。结果表明,研究区表层土壤普遍存在不同程度的重金属污染,以轻微至轻度污染级别为主,其中Cd和As存在少量重度污染点位,比例分别为3.00%和0.19%。研究区重金属富集主要受工矿企业活动影响,浓集中心集中在金属矿山和印染企业周边,具有沿水系向低地势平原区迁移趋势。研究区范围Cd和Hg具有潜在的较高生态风险。利用GIS系统,将各样点重金属土壤污染程度、富集因子(EF)和潜在生态危害评价结果,在研究区农用地土地利用现状图斑上进行空间叠加,可实现从地理空间上的土壤重金属污染范围界定、重金属人为成因污染判别和潜在生态危害风险空间预警。     

太湖流域典型农田土壤磷库演变特征及环境风险预测

水体磷污染及其产生的富营养化等生态效应已成为流域性突出问题,其主要来源之一为农田磷流失。磷流失主要受土壤磷形态及有效性等因素影响,而土壤磷库又具有很强的空间分异特征。因此,聚焦水体富营养化较为突出的太湖流域,选取典型水旱轮作农田土壤为研究对象,基于系统随机布点法采集农田土壤样本319份,植株样本83株,分析土壤磷库演变规律并预测其环境风险。研究结果表明：与全国第二次土壤普查及2009年前期调查结果相比,该区域土壤全磷与有效磷(Olsen-P)含量均显著提高。根据水稻土Olsen-P的临界意义,该区域93.1%的农田土壤有效磷含量超过10 mg·kg^–1,土壤基本不缺磷;有效磷高于20 mg·kg^–1占总土壤样本的65.2%,说明大部分农田土壤磷库处于盈余状态。进一步基于磷素生物有效性的分级方法(biologically based P,BBP)对土壤磷的生物有效性进行分析,发现氯化钙磷(CaCl₂-P)、柠檬酸磷(Citrate-P)、酶提取磷(Enzyme-P)以及盐酸磷(HCl-P)与Olsen-P均呈极显著正相关(...     

化工厂污染区复垦后的土壤和蔬菜重金属含量与风险评价

以湖南省某化工厂重金属污染土壤复垦区为研究区域,采集复垦区和对照区的表层土壤(0~20 cm)与当季蔬菜(莴笋、大蒜、紫苏、白菜、薤白和艾蒿),分析了样品中五种重金属含量(Cd、Zn、Cu、Pb、Cr),然后对复垦后土壤环境进行安全性评价。结果表明:原厂区内、排污口及二次污染区土壤重金属Cd明显高于其他区域,客土处理土壤明显低于原土Cd含量,但含量依然超标,单因子污染指数为1.65~5.42,土壤重金属综合污染指数为1.22~3.95;根茎类蔬菜中Cd含量超过限量标准,含量最高的为薤白,超过标准90%,影响居民健康;土壤和蔬菜中Zn、Cu、Pb、Cr元素均达标。翻耕与客土复垦有一定效果,但是复垦土壤仍然不适合种植农作物。     

有机酸对红壤磷素潜在环境风险的影响

从两个方面初步探讨了有机酸对红壤磷素潜在环境风险的影响,一是有机酸对红壤固磷能力的影响,二是有机酸对红壤固定磷向液相释放的影响。研究结果表明不同类型有机酸在这两个方面的影响是不同的,以柠檬酸为代表的二羧酸可以显著减少红壤对磷的固定量,大大提高了土壤向水体释放磷的能力,增大了土磷的潜在环境风险;而以草酸为代表的三羧酸则可以不同程度上增加土壤的固磷能力,且可使已经存在于液相中的磷再次被吸附,进而减缓或消除土磷了的潜在环境风险。     

基于AHP-Topsis的南通市环境灾害风险评价

从环境灾害风险的脆弱性、暴露性与恢复能力3个方面,构建了江苏省南通市环境灾害风险评价的指标体系.基于Topsis方法,应用AHP方法赋权,对南通环境灾害风险的区域差异进行了分析.结果表明,南通市7个不同区域的环境灾害风险差异较大,海安风险最小,而如皋风险最大,风险由小到大的顺序依次为:海安＜海门＜通州区＜南通市区＜如东＜启东＜如皋.环境风险的主要原因在于工业化与城市化影响下工业“三废”对环境的潜在影响,以及环保投入的力度等.因此,南通市应减少人为环境影响,增加环保投入,以降低环境灾害风险.     

生物质炭中多环芳烃的潜在环境风险研究进展

作为土壤改良剂和环境污染修复材料,生物质炭在近年来得以广泛应用。生物质炭制备过程中会产生一定量的多环芳烃(PAHs),对其潜在环境负面效应和风险尚缺乏应有的认识。本文总结了生物质炭中PAHs的形成机理、影响因素(包括原材料、裂解温度、裂解升温速率和保留时间等)、总量和生物有效含量及其分析方法,旨在为生物质炭在环境中的安全应用提供理论依据和技术参考。     

紫色土磷素流失的环境风险评估-土壤磷的“临界值”

采用室内培养的方法,研究了3种类型的紫色土旱地和淹水土壤磷素流失的环境阈值。结果表明:无论是淹水土壤或旱地生境,3种紫色土Olsen-P与CaCl2-P之间都存在一个"临界值",酸性、中性和钙质紫色土磷素淋失临界点的Olsen-P含量分别为67.2、85.8和113.8 mg kg-1。淹水土壤磷素环境敏感值在酸性、中性和钙质紫色土上,Olsen-P含量分别为49.2、77.9和92.1 mg kg-1。3种紫色土在淹水还原条件下土壤磷环境敏感临界值比旱地低,淹水还原条件提高了紫色土磷向水体释放的风险。淹水土壤Olsen-P含量与田表水TP、DP浓度之间存在"临界值",酸性、中性和钙质土临界值处土壤Olsen-P含量分别为(65±1.41)mg kg-1(、96.7±2.7)mg kg-1和(105.5±1.1)mg kg-1。土壤0.01 mol L-1 CaCl2-P与田表水TP、DP之间呈极显著的线性关系。可以利用这些指标对紫色土区域土壤磷环境风险进行评价,并确定区域磷肥的最佳管理策略。