土壤污染的生态毒理诊断研究进展

土壤生态毒理学是污染土壤生态风险评价以及土壤污染控制的理论依据,土壤环境中有毒物质的生态毒理效应及其分子机制的研究是土壤生态毒理学的核心内容.土壤污染生态毒理诊断集合了土壤污染的全部信息,提供了土壤的整体毒性效应.因此,开展土壤污染生态毒理诊断研究有重要的理论意义和现实意义.本文在参考国内外土壤污染生态毒理诊断研究成果的基础上,介绍了常用土壤污染生态毒理效应诊断方法和指标,并探讨了不同方法的利弊.传统毒理诊断方法往往只能表征胁迫的程度,不能解释损伤和响应发生分子机理.污染土壤毒性评估的生物标记物和土壤污染分子诊断技术,可深入探讨外源胁迫下生物的解毒机制.本文对其进行了较为系统的介绍,并对未来的研究趋势进行展望.     

土壤环境污染的生态毒理学诊断方法研究进展

土壤污染诊断是土壤环境清洁过程中必不可少的重要环节。单纯依靠化学方法进行污染诊断,不能表征土壤环境的整体质量特征。因此,需要发展污染生态毒理学诊断方法。本文阐述了污染土壤的生态毒理诊断研究的特殊性和重要性,扼要概述了建立土壤污染生态毒理学诊断方法的考虑及准则,对污染土壤的生态毒理诊断国内外研究现状进行综述,并提出今后的研究方向。     

光和噪声污染胁迫下城市生态斑块鸟类风险评价

为应对城市生态斑块光污染、噪声污染范围快速扩张和强度增加对鸟类带来的生态风险,探讨了将微观鸟类风险阈值与宏观光污染、噪声污染分布数据结合进行生态风险评价的全链条研究方法,具体包括：探究微观层面光、声污染胁迫下鸟类生态风险阈值,分别获得光污染对黄雀和栗鹀寤寐节律及声污染对画眉鸟退避行为的生态风险阈值,并提出由实验室环境中获得的鸟类光污染强度风险阈值推算室外夜间混合光环境中鸟类光污染强度风险阈值的方法;同时获取宏观光、声环境分布数据,其中光环境分布数据基于Luojia 1-01和Jilin 1-7B夜光遥感影像获得,声环境分布数据通过软件模拟、实测校核、ArcGIS属性赋予等系列操作获得;结合微观鸟类风险阈值和宏观光、声环境分布数据开展生态风险评价,以典型城市生态斑块为实例分析光污染和噪声污染胁迫下鸟类生态风险分布特征;搭建生态风险评价平台并进行鸟类生态风险可视化展现。该生态风险评价方法可为城市宏观区域光、声污染生态风险的快速评价提供科学规范的研究和技术范例。     

污染生态化学:现状与展望

随着生态学和环境化学的发展和交叉,形成了一门新的学科－污染生态化学。目前,它的主要研究内容包括化学污染物的迁移转化及其微观生态化学过程、化学污染的生态效应与毒理及生态风险评价、全球变化的生态化学、生态系统中化学污染物的分析与监测和污染控制生态化学等５个方面。在知识创新的科学目标指导下,污染生态化学今后的工作必须加强从理论上进行突破,在对基础研究进行深入的同时,应该特别注意开展一些应用研究,从而实现     

生态风险评价方法述评

生态风险是由环境的自然变化或人类活动引起的生态系统组成、结构的改变而导致系统功能损失的可能性。生态风险评价是定量预测各种风险源对生态系统产生风险的或然性以及评估该风险可接受程度的方法体系,因而是生态环境风险管理与决策的定量依据。在介绍了生态风险概念的基础上,按照风险源性质的分类标准将生态风险划分为化学污染类风险源、生态事件类风险源、复合类风险源3类,并分别论述了3类生态风险对应评价方法的特点与发展的方向。另外,针对生态风险评价研究的现状,讨论了我国生态风险研究的优先领域,包括建立急性、慢性毒理数据库,构建外来生物入侵风险评价标准等,同时,建议将综合概率统计学、复杂系统理论与遥感技术等手段引入生态风险评价方法中,以进一步提高风险评价结果在生态风险管理中的有效性。     

生态毒理基因组学和生态毒理蛋白质组学研究进展

将基因组学和蛋白质组学知识整合到生态毒理学中形成了生态毒理基因组学和生态毒理蛋白质组学.通过生态毒理基因组学和生态毒理蛋白质组学的研究能够在基因组和蛋白质组水平更深入理解毒物的作用机制,寻找更敏感、有效的生物标记物,形成潜在的强有力的生态风险评价工具.介绍了生态毒理基因组学和生态毒理蛋白质组学的研究进展,以及DNA芯片技术和2D-凝胶电泳技术在持久性有毒污染物的生态毒理学研究中的应用.     

蚯蚓在环境安全研究中的应用

蚯蚓在环境污染的生态毒理学诊断方面具有重要生态学意义,这是蚯蚓在环境安全研究中应用的基础。本文概述了蚯蚓生态毒理诊断的一些试验方法,包括急性毒性试验法、田间生态毒性试验法、污染环境的生物检测法和微观生物指标检测法。在这基础上,就蚯蚓的环境安全生态指示研究进展进行了剖析与展望。还从蚯蚓处理生活垃圾与农业有机废弃物以及污水的蚯蚓过滤处理等应用方面,论述了蚯蚓在污染环境解毒过程中的重要生态作用及今后的发展方向。     

印度工业毒理研究中心简介

印度工业毒理中心建于1965年11月4日。位于印度Mahatma Gandhi Marg, Lucknow.所长为P. K. Ray博士。其主要任务是:①通过系统流行病学调查,评价工农业工作人员接触的工作环境对健康的影响;②对工农业和日常生活中所用的化学品开展安全评价;③开展化学污染物作用模式的研究,建立有关学科的研究手段;④建立适用的诊断方法,提出治疗和预防措施;⑤收集和分发有害化学品的资料。     

影响有机化学品快速生物降解性的分子结构参数研究进展

合成有机化学品污染日益严重, 生物降解性是影响其在环境中归趋的重要因素。快速生物降解测试是初级的生物降解测试, 可快速评价化合物的初级生物降解性能, 目前已广泛应用于化合物的生态风险评价, 在化合物的生物降解测试中具有非常重要的地位。文章首先综述了有机化学品的快速生物降解性在环境风险评价中的应用及应用中存在的问题。生物降解性主要取决于化合物的结构, 文章进一步探讨了可能影响有机化学品快速生物降解性的理化性质参数、空间拓扑参数、电性效应参数等分子结构参数, 并讨论了它们在有机化学品结构与快速生物降解性定量构效关系研究及快速生物降解性测试指导中的应用前景。     

持久性有机污染土壤的植物修复及其机理研究进展

随着人类对化学品的依赖程度越来越高,环境的有机污染状况也越来越严重.有机污染土壤的植物修复是指利用植物在生长过程中,吸收、降解、钝化有机污染物的一种原位处理污染土壤的方法,具有应用成本低、生态风险小、对环境副作用小等特点.本文综述了近年来国内外有机污染土壤的植物修复研究进展情况,重点介绍了多氯联苯、多环芳烃、农药和硝基芳香化合物等持久性有机污染物的植物修复,阐述了有机污染土壤植物修复的关键机制,并分析了该技术在实际工程应用中的局限性及应考虑的因素.最后,指出了今后该领域的重点研究方向.     

Environmental fate of the chemical mixtures: Crude oil,JP‐5, mineral spirits,and diesel fuel

Petroleum hydrocarbon mixtures in soils and groundwater present unique challenges in the estimation of potential human exposures and subsequent health risks. A major component of risk assessment affected by mixtures is the evaluation of environmental fate. The fate of petroleum mixtures may be evaluated by using either of three approaches: (1) the evaluation of the fate of indicator chemical(s), (2) the evaluation of the fate of the mixture as a whole with a surrogate, and (3) the evaluation of the fate of the hydrocarbon mixture as a whole. The limiting factor in the selection of an approach is the availability of information on specific chemical constituents in the mixture. The evaluation of environmental fate requires quantitative information regarding the distribution, mobility, and degradation/transformation as represented by various physicochemical properties. In addition to the availability of this information, the selection of the evaluation method should be consistent with the goals of the project, as each approach will produce different results. This presentation discusses the issues related to the identification and implementation of each of the approaches to the evaluation of the environmental fate of four petroleum mixtures (crude oil, JP‐5, mineral spirits, and diesel) for risk assessment purposes.     

Estimating the Toxicity of Pesticide Mixtures to Aquatic Organisms: A Review

A major difficulty in addressing chemical mixtures through legislation or regulations revolves around our limited understanding of their potential impacts. This review provides an overview of recent research on pesticide mixture toxicity to aquatic biota and the methods employed to predict toxic effects. The most common approaches are to assume concentration-addition or independent action of chemicals in a mixture. There are a number of cases in the literature of interactions between pesticides. However, models accounting for possible interactions between mixture components are used infrequently. Although results are limited, studies investigating the effects of pesticide mixtures have not demonstrated significant synergism at environmentally relevant concentrations. Based on the results of our review, we conclude that the concentration-addition model is a generally conservative and practical first-tier model for the ecological assessment of pesticide mixtures in aquatic systems.     

Chemical Mixtures: An Unsolvable Riddle?

It is difficult to overstate the complexity of assessing risks from chemical mixtures. For every valid reason to assess risks from mixtures, there appears an equally valid question as to whether it is possible to do so in a scientifically rigorous and relevant manner. Because so few data exist for mixtures, current mixture assessment methods must rely on untested assumptions and simplifications. That the accuracy of risk estimates improve with the number of chemicals assessed together as mixtures is a valid assumption only if assessment methods for mixtures are better than those based on individual chemicals. On the other hand, arbitrarily truncating a mixture assessment to make it manageable may lead to irrelevant risk estimates. Ideally, mixture assessments should be as broad as necessary to improve accuracy and reduce uncertainty over assessments that only use toxicity data for single chemicals. Further broadening the scope may be ill advised because of the tendency to increase rather than decrease uncertainty. Risk assessment methods that seek to be comprehensive at the expense of increased uncertainty can hardly be viewed as improvements. It would be prudent to verify that uncertainty can be reduced before burdening the risk assessment process with more complexity.     

Assessing Toxicity of Mixtures: The Search for Economical Study Designs

Toxicity screening and testing of chemical mixtures for interaction effects is a potentially onerous task due to the sheer volume of combinations that may be of interest. We propose an economical approach for assessing the interaction effects of chemical mixtures that is guided by risk-based considerations. We describe the statistical underpinnings of the approach and use examples from the published literature to illustrate concepts of local versus global mixture assessment. Our approach employs a sequential testing procedure to find the dose combinations that define the dose boundary for a specified acceptable risk level. The first test is conducted for a dose combination consisting of the acceptable doses of each individual chemical in the mixture. The outcome of this first test indicates the dose combination that should be tested next. Continuing in this manner, the boundary of dose combinations for the specified acceptable risk level can be approximated based on measurements for relatively few dose combinations. Dose combinations on one side of the boundary would have responses less than the response associated with the acceptable risk level, and dose combinations on the boundary would be acceptable levels of exposure for the mixture.     

Reliable predictive computational toxicology methods for mixture toxicity: toward the development of innovative integrated models for environmental risk assessment

A main objective in the field of mixture toxicity is to determine how well combined effects are predictable based on the known effects of mixture constituents. Conducting toxicity tests for all conceivable combinations of chemicals, to understand all mechanisms in the combined toxicity of environmental pollutants, is virtually unfeasible due to cost- and time-consuming procedures. Therefore, predictive tools for mixture toxicity are required to be developed within the applicable range of predictive toxicology. The concept of concentration addition (CA) model is often considered a general method for estimating mixture toxicity at the regulatory level. In the long run, however, the possibility of toxicological synergism between mixture components actually occurs, especially from the no-effect level or non-toxic substances. This is ignored under the CA concept, and needs to be examined and integrated into existing addition models at a scientific level, this paper reviews existing integrated models for estimating the toxicity of complex mixtures in literature. Current approaches to assess mixture toxicity and the need for new research concepts to overcome challenges which recent studies have confronted are discussed, particularly those involved in computational approaches to predict mixture toxicity in an environment risk assessment based on mixture components.     

Current Risk Assessment Approaches to Address Petroleum Hydrocarbon Mixtures in Soils

Products that exist as complex chemical mixtures, such as petroleum products, are used widely in commerce, and accidental releases of these products into the environment have led to thousands of contaminated sites nationwide. Developing sound estimates of potential health risks posed by these sites is challenging because of the composition of these products, their behavior in the environment, and the paucity of toxicological information available for many of the component compounds. In developing risk based cleanup goals for petroleum products and other complex commercial mixtures, the simplest approach is to assume that the entire mixture is comprised of the most toxic constituent, particularly when standards are unavailable for each of the components of the mixture. This approach often results in excessively conservative regulatory goals; thus, methods are needed which more accurately reflect the actual composition and aggregate toxicity of the mixture. Three approaches for the development of risk based soil cleanup goals for petroleum hydrocarbon mixtures are identified and illustrated using mineral spirits as an example. For the examples presented, estimates of the proportions of components in mineral spirits were based on virgin, unused product; however, detailed component analysis of weathered samples may permit the calculation of more precise, site specific cleanup goals.     

Concentration Addition,Independent Action and Generalized Concentration Addition Models for Mixture Effect Prediction of Sex Hormone Synthesis In Vitro

Humans are concomitantly exposed to numerous chemicals. An infinite number of combinations and doses thereof can be imagined. For toxicological risk assessment the mathematical prediction of mixture effects, using knowledge on single chemicals, is therefore desirable. We investigated pros and cons of the concentration addition (CA), independent action (IA) and generalized concentration addition (GCA) models. First we measured effects of single chemicals and mixtures thereof on steroid synthesis in H295R cells. Then single chemical data were applied to the models; predictions of mixture effects were calculated and compared to the experimental mixture data. Mixture 1 contained environmental chemicals adjusted in ratio according to human exposure levels. Mixture 2 was a potency adjusted mixture containing five pesticides. Prediction of testosterone effects coincided with the experimental Mixture 1 data. In contrast, antagonism was observed for effects of Mixture 2 on this hormone. The mixtures contained chemicals exerting only limited maximal effects. This hampered prediction by the CA and IA models, whereas the GCA model could be used to predict a full dose response curve. Regarding effects on progesterone and estradiol, some chemicals were having stimulatory effects whereas others had inhibitory effects. The three models were not applicable in this situation and no predictions could be performed. Finally, the expected contributions of single chemicals to the mixture effects were calculated. Prochloraz was the predominant but not sole driver of the mixtures, suggesting that one chemical alone was not responsible for the mixture effects. In conclusion, the GCA model seemed to be superior to the CA and IA models for the prediction of testosterone effects. A situation with chemicals exerting opposing effects, for which the models could not be applied, was identified. In addition, the data indicate that in non-potency adjusted mixtures the effects cannot always be accounted for by single chemicals.     

Soil ecotoxicology: state of the art and future directions

Developments in soil ecotoxicology started with observations on pesticide effects on soil invertebrates in the 1960s. To support the risk assessment of chemicals, in the 1980s and 1990s development of toxicity tests was the main issue, including single species tests and also more realistic test systems like model ecosystems and field tests focusing on structural and functional endpoints. In the mean time, awareness grew about issues like bioavailability and routes of exposure, while biochemical endpoints (biomarkers) were proposed as sensitive and potential early-warning tools. In recent years, interactions between different chemicals (mixture toxicity) and between chemical and other stressors attracted scientific interest. With the development of molecular biology, omics tools are gaining increasing interest, while the ecological relevance of exposure and effects is translating into concepts like (chemical) stress ecology, ecological vulnerability and trait-based approaches. This contribution addresses historical developments and focuses on current issues in soil ecotoxicology. It is concluded that soil ecotoxicological risk assessment would benefit from extending the available battery of toxicity tests by including e.g. isopods, by paying more attention to exposure, bioavailability and toxicokinetics, and by developing more insight into the ecology of soil organisms to support better understanding of exposure and long-term consequences of chemical exposure at the individual, population and community level. Ecotoxicogenomics tools may also be helpful in this, but will require considerable further research before they can be applied in the practice of soil ecotoxicological risk assessment.     

Multiplicity-adjusted inferences in risk assessment: benchmark analysis with quantal response data

A primary objective in quantitative risk or safety assessment is characterization of the severity and likelihood of an adverse effect caused by a chemical toxin or pharmaceutical agent. In many cases data are not available at low doses or low exposures to the agent, and inferences at those doses must be based on the high-dose data. A modern method for making low-dose inferences is known as benchmark analysis, where attention centers on the dose at which a fixed benchmark level of risk is achieved. Both upper confidence limits on the risk and lower confidence limits on the "benchmark dose" are of interest. In practice, a number of possible benchmark risks may be under study; if so, corrections must be applied to adjust the limits for multiplicity. In this short note, we discuss approaches for doing so with quantal response data.     

Effects of Picoxystrobin and 4-n-Nonylphenol on Soil Microbial Community Structure and Respiration Activity

There is widespread use of chemical amendments to meet the demands for increased productivity in agriculture. Potentially toxic compounds, single or in mixtures, are added to the soil medium on a regular basis, while the ecotoxicological risk assessment procedures mainly follow a chemical by chemical approach. Picoxystrobin is a fungicide that has caused concern due to studies showing potentially detrimental effects to soil fauna (earthworms), while negative effects on soil microbial activities (nitrification, respiration) are shown to be transient. Potential mixture situations with nonylphenol, a chemical frequently occurring as a contaminant in sewage sludge used for land application, infer a need to explore whether these chemicals in mixture could alter the potential effects of picoxystrobin on the soil microflora. The main objective of this study was to assess the effects of picoxystrobin and nonylphenol, as single chemicals and mixtures, on soil microbial community structure and respiration activity in an agricultural sandy loam. Effects of the chemicals were assessed through measurements of soil microbial respiration activity and soil bacterial and fungal community structure fingerprints, together with a degradation study of the chemicals, through a 70 d incubation period. Picoxystrobin caused a decrease in the respiration activity, while 4-n-nonylphenol caused an increase in respiration activity concurring with a rapid degradation of the substance. Community structure fingerprints were also affected, but these results could not be directly interpreted in terms of positive or negative effects, and were indicated to be transient. Treatment with the chemicals in mixture caused less evident changes and indicated antagonistic effects between the chemicals in soil. In conclusion, the results imply that the application of the fungicide picoxystrobin and nonylphenol from sewage sludge application to agricultural soil in environmentally relevant concentrations, as single chemicals or in mixture, will not cause irreversible effects on soil microbial respiration and community structure.