大气中持久性有机污染物的采样技术进展

大气是全球持久性有机污染物(persistent organic polutants,POPs)监测的重要环境介质,大气中POPs的采样技术是准确表征大气中POPs赋存水平的关键所在。近年来大气中POPs的采样技术发展很快。本文介绍了大气中POPs的两类采样方法:主动采样法(active air sampling,AAS)和被动采样法(passive air sampling,PAS),总结了新型吸附材料和新型采样器研发的成果,讨论了不同类型的采样方法的特点,对比分析了不同采样方法获得的POPs监测数据,并提出今后应用不同POPs大气采样技术在监测数据可对比性研究方面值得关注的问题。     

大气中持久性有机污染物在气相和颗粒相中的分配特征研究进展

大气中持久性有机污染物(POPs)的气(气相)-粒(颗粒相)分配是影响POPs在大气中分布、迁移和转化的一个重要因素,研究POPs的气-粒分配特征有助于提高POPs环境归趋预测的准确性,对区域范围内的大气POPs污染防治具有重要意义.本文简要介绍了两种经典的POPs气-粒分配理论及模型,总结了有关大气中几类典型POPs在气相和颗粒相中的分配特征研究的最新进展,讨论了不同种类POPs气-粒分配的一些差异性特征和可能的影响因素,并提出了大气中新型POPs气-粒分配特征研究中亟待解决的问题.     

持久性有机污染物在大气与植物间交换过程研究进展

大气、植物间持久性有机物污染物(POPs)的交换行为是控制POPs进入食物链,及影响其全球范围内迁移、分布的重要环节.本文着重介绍了大气、植物间POPs交换过程方面的研究现状;总结了其影响因素,主要包括POPs本身的理化性质(lgKOA)、植物特性(叶片表面形态、脂质含量、表皮的可渗透性)以及环境温度;提出了目前大气、植物间POPs交换过程研究中存在的部分问题,以及今后可能的发展方向.     

偏远高山湖泊沉积物中持久性有机污染物的沉积记录研究

持久性有机污染物(POPs)因具有半挥发性,可随大气长距离传输迁移到偏远的高山地区,对当地生态环境造成潜在威胁,因而POPs在这些地区的归趋及行为受到广泛关注.偏远高山地区环境中的POPs主要来源于大气沉降过程,湖芯能较好地保存大气污染物的沉降信息以及年代信息,被称为"天然档案室",常被用于研究污染物的沉降历史和演变规律.本文首先介绍了几种常用于湖芯定年的放射性核素定年方法,然后综述了不同区域高山湖芯中POPs的时空变化趋势以及影响因素,最后针对偏远高山沉积物研究存在的不足对未来研究提出了几点建议.     

植物--实时富集大气持久性有机污染物的被动采样平台

对植物富集大气持久性有机污染物(POPs)的机理及其在大气POPs污染监测中的应用,主要是地衣、苔藓、树叶、树皮作为大气POPs的被动采样器在大气POPs监测中的应用做了介绍,指出树木“时间隧道”作为实时记录大气历史污染状况的又一“新标本”将在大气污染“历史监测”中发挥重要作用．     

青藏高原纳木错流域持久性有机污染物的多介质迁移与归趋模拟

南亚排放的持久性有机污染物(POPs)可随大气传输到青藏高原,然而POPs在高原多介质间的迁移与分配尚不清晰。本研究利用三级逸度模型对4种POPs(六六六α-HCH,滴滴涕p,p'-DDT,菲Phe和苯并芘Ba P)在纳木错流域的迁移与归趋进行了模拟。结果表明,大气沉降是该区域污染物的主要输入过程,而降解损失则是主要的输出途径。就最终归趋而言,土壤是POPs在纳木错流域的重要储库,其存储了大于50%的POPs。此外,湖水和沉积物分别对α-HCH和PAHs具有较强的存储能力。灵敏度分析的结果表明,环境温度、大气中POPs的浓度及其理化性质是影响POPs在环境中分布的关键参数。本研究明确了纳木错流域不同POPs的迁移方向和归趋特征,这将为青藏高原生态安全评估提供科学依据。     

苔藓和地衣在指示偏远地区大气持久性有机污染物中的应用

持久性有机污染物(POPs)因具有半挥发性和持久性,可随大气迁移到偏远的高山地区甚至人迹罕至的两极地区,对当地生态环境带来严重威胁,因而受到大量关注.苔藓和地衣在偏远高山地区分布广泛,通常被用作高山地区大气POPs分析的天然被动采样器.本文首先介绍了苔藓/地衣用于指示POPs污染的特点,然后分别阐述了苔藓/地衣在指示偏远地区POPs时间变化和空间分布两方面的应用,最后本文对苔藓/地衣用于指示大气POPs污染所存在的问题提出了几点建议,并分析了未来研究的发展趋势.     

ASE 快速溶剂萃取仪提取持久性有机污染物（POPs）的应用（一）

持久性有机污染物（POPs）是指具有高毒性、生物蓄积型和半挥发性、在环境中持久存在且能在大气中长距离迁移并沉积回地球的极地地区,对人类监控和环境造成严重危害的有机化学污染物,1997年,联合国环境规划署决定对12种POPs物质立即采取行动减少或消除它们的产生.这12种有机污染物包括9种有机氯杀虫剂：滴滴涕、六氯苯、氯丹、     

鸟类对持久性有机污染物的定向传输作用研究进展

传统意义上认为,持久性有机污染物（POPs）的传输途径主要有两种形式,一种是通过挥发之后进入大气,然后通过长距离大气传输、蚱蜢效应、高山冷凝效应等方式进行传输;另一种是进入水体中,通过水流的搬运作用传输,从而进入湖泊、河流生态系统,甚至可以通过洋流的长距离输送到达北极等高纬地区．另外,海鸟、候鸟和留鸟可以对POPs进行...     

墨西哥在一个区域合作的框架之内成功消除氯丹

一组众所周知的化学药品已被划分为持久性有机污染物（POPs），它们的性质包括高毒性、在环境中保留时间长、在大气中可长距离传播和能在脂肪组织中累积．与持久性有机污染物直接接触可以导致急性效应、持久性有机污染物用作农药的事故，例如，已经有使农业劳动者致死或重病的例子。     

Relationship between heavy metal concentrations of herbaceous plants and soils at four Pb-Zn mining sites in Yunnan, China

This paper studied the relationship between heavy metal concentrations of herbaceous plants and soils at four Pb-Zn mining sites in Yunnan, China. 50 herbaceous plant samples of 9 plant species from 4 families and 50 soil samples were collected and then ana1yzed for the tota1 concentrations of Pb, Cd, and Zn. The results showed that the average concentrations of Pb, Cd, and Zn in soil samples were 3772.83, 168.81, and 5385.65 mg/kg, respectively. The average concentrations of Pb, Cd, and Zn were 395.68, 28.14, and 1664.20 mg/kg in the shoots, and 924.12, 57.25, and 1778.75 mg/kg in the roots, respectively. Heterospecific plants at the same site and conspecific plants at various sites had different average levels of Pb, Cd, and Zn, both in the shoots and the roots. Enrichment coefficients of Pb, Cd, and Zn were greater than 1 in 2, 3, and 9 herbaceous plant samples, respectively. Translocation factors of Pb, Cd, and Zn were greater than 1 in 10, 17, and 25 herbaceous plant samples, respectively. In all 50 samples, the concentrations of Pb, Cd, and Zn between the shoots and the roots, the shoots, and the soils, and the roots and the soils had significant positive relationships.     

Recognizing reflexivity among conservation practitioners

When deciding how to conserve biodiversity, practitioners navigate diverse missions, sometimes conflicting approaches, and uncertain trade-offs. These choices are based not only on evidence, funders’ priorities, stakeholders’ interests, and policies, but also on practitioners’ personal experiences, backgrounds, and values. Calls for greater reflexivity—an individual or group's ability to examine themselves in relation to their actions and interactions with others—have appeared in the conservation science literature. But what role does reflexivity play in conservation practice? We explored how self-reflection can shape how individuals and groups conserve nature. To provide examples of reflexivity in conservation practice, we conducted a year-long series of workshop discussions and online exchanges. During these, we examined cases from the peer-reviewed and gray literature, our own experiences, and conversations with 10 experts. Reflexivity among practitioners spanned individual and collective levels and informal and formal settings. Reflexivity also encompassed diverse themes, including practitioners’ values, emotional struggles, social identities, training, cultural backgrounds, and experiences of success and failure. Reflexive processes also have limitations, dangers, and costs. Informal and institutionalized reflexivity requires allocation of limited time and resources, can be hard to put into practice, and alone cannot solve conservation challenges. Yet, when intentionally undertaken, reflexive processes might be integrated into adaptive management cycles at multiple points, helping conservation practitioners better reach their goals. Reflexivity could also play a more transformative role in conservation by motivating practitioners to reevaluate their goals and methods entirely. Reflexivity might help the conservation movement imagine and thus work toward a better world for wildlife, people, and the conservation sector itself.     

AQUATOX: Modeling environmental fate and ecological effects in aquatic ecosystems

AQUATOX combines aquatic ecosystem, chemical fate, and ecotoxicological constructs to obtain a truly integrative fate and effects model. It is a general, mechanistic ecological risk assessment model intended to be used to evaluate past, present, and future direct and indirect effects from various stressors including nutrients, organic wastes, sediments, toxic organic chemicals, flow, and temperature in aquatic ecosystems. The model has a very flexible structure and provides multiple analytical tools useful for evaluating ecological effects, including uncertainty analysis, nominal range sensitivity analysis, comparison of perturbed and control simulations, and graphing and tabulation of predicted concentrations, rates, and photosynthetic limitations. It can represent a full aquatic food web, including multiple genera and guilds of periphyton, phytoplankton, submersed aquatic vegetation, invertebrates, and fish and associated organic toxicants. It can model up to 20 organic chemicals simultaneously. (It does not model metals.) Modeled processes for organic toxicants include chemodynamics of neutral and ionized organic chemicals, bioaccumulation as a function of sorption and bioenergetics, biotransformation to daughter products, and sublethal and lethal toxicity. It has an extensive library of default biotic, chemical, and toxicological parameters and incorporates the ICE regression equations for estimating toxicity in numerous organisms. The model has been implemented for streams, small rivers, ponds, lakes, reservoirs, and estuaries. It is an integral part of the BASINS system with linkage to the watershed models HSPF and SWAT.     

Ecotypes diversity in autumn olive (Elaeagnus umbellata Thunb): A single plant with multiple micronutrient genes

Elaeagnus umbellata, a member of the Elaeagnaceae family, is native to Pakistan, China, India, Korea, and Japan. It is found commonly at altitudes ranging from 1200 to 2100 m and thrives on eroded and degraded land due to its ability to fix nitrogen. The plant also grows under variable pH (4-8) and drought, and is used locally as fuel wood, fencing, fodder, basket making, and shelterbelts. The fruit of the plant is well known for its essential nutrients and medicinal compounds such as vitamins, minerals, essential fatty acids, carotenoids (lycopene), soluble solids, and sugars. Medicinally, it is widely believed to protect against myocardial infections, pulmonary infections, and various forms of cancers. Ten ecotypes from variable microclimatic conditions were investigated for their morphological, molecular and biochemical diversity improvement and commercialization purposes. Comparisons and disabilities indicated significant variability in terms of morphological (plant height, number of branches, thorn size and number, leaf area, fruit size, 100 fruit weight, and yield), molecular (SDS-PAGE), and micro- and macronutrient (vitamin C, Fe, mg, P, Na, K, essential oils, and sugar) bases among the ecotypes. This variability will be helpful in developing commercial varieties of the plant utilizing the conventional techniques of selection and hybridization for economic activities. The plant has ample quantities of multiple micronutrients, thus indicating their expression through a powerful promoter at one place (fruit mesocarp). Efforts to identify and isolate the micronutrient genes (vitamin A, C, E, and Fe), the deficiency of which causes malnutrition and disabilities within the population of developing countries. Micronutrient genes have also been initiated for their characterization and future transformation into staple food crops for stable bio-fortification.     

Geochemistry of the barkinite liptobiolith (Late Permian) from the Jinshan Mine,Anhui Province,China

This paper discusses the geochemistry and mineralogy of the barkinite liptobiolith of the Late Permian age from the Jinshan Mine, Guangde County, Anhui Province, China. Samples were examined using inductively coupled plasma-mass spectroscopy, X-ray fluorescence, cold-vapor atomic absorption spectrometry, ion-selective electrode, sequential chemical extraction, scanning electron microscopy equipped with energy-dispersive X-ray, and optical microscopy. The coal is a medium-ash and high-sulfur resource. Minerals in the coal are composed of kaolinite, pyrite, calcite, and quartz. Pyrite and calcite are derived from seawater during peat accumulation. Quartz in the coal is of authigenic origin. Part of the kaolinite is from a land-source region, and part occurs as cell-fillings and is of authigenic origin. The results also indicate that the barkinite liptobiolith contains some toxic elements in high concentrations. Elements including Li, Be, Si, Sc, Ti, V, Cr, Fe, Ga, Se, Y, Zr, Mo, the rare earth elements (REEs), W, Hg, Tl, Pb, Th, and U in the coals are enriched in the barkinite liptobiolith. Results of sequential chemical extraction showed that Li, Sc, Ti, Cr, Y, Zr, REEs, and Th in the coal mainly occur as silicates, while Be and W are related to organic matter. Pyrite is the dominant source of S, Mo, Hg, Tl, and Pb. Gallium only occurs in silicate, and U and V occur both in organic and silicate associations.     

Multi-level complexity in the use of plant allelochemicals by aposematic insects

Summary As recognized by Miriam Rothschild as early as the 1960s and repeatedly emphasized in her papers, the use, misuse, or non-use of plant allelochemicals by insects is extremely variable and difficult to predict, at many levels of time, space, and biological organization. Although certain patterns that reoccur have been important in the development of ecological theory, the optimization of cost-benefit equations involving two or three trophic levels, each with large numbers of individuals, populations, and species in erratic and complex interactions, produces unexpected and fascinating scenarios. The development of rapid colorimetric and chromatographic analyses for several types of plant allelochemicals, notably certain groups of alkaloids, cardiac and cyanogenic glycosides, phenolics, terpenes, and glucosinolates, has permitted a detailed investigation of the variation and flow of these substances in natural organisms and ecosystems. The results of these analyses, in our hands mostly for pyrrolizidine alkaloids (PAs), do not suggest a straightforward classical choice by the aposematic insect to simply sequester or synthesize its defences. Rather, they reveal a confusing variety of diffuse and complex patterns that become increasingly closer to chaos as they are multiplied across structures, species, sexes, stages, sites, seasons, and selective regimes. We present a model reflecting results of analyses at this chemoecological interface. Depending upon an initial option, involving the recognition (or not) of a plant allelochemical, the herbivore will face thereafter options to ingest it (or not), and then to tolerate and absorb (or detoxify and excrete), modify (or not), passively, actively or selectively accumulate, turn over (or not), distribute (or concentrate), and use this compound in a variety of growth, defense, or reproductive functions. The herbivore can also quantitatively or qualitatively regulate the intensity or dispersion of its attack on the plant tissues, in order to modify feedback loops of selection on the plant and its chemicals which exist in most of the earlier steps, or those with its predators and parasites that occur in the later ones. Options that lead to mutualism through positive feedback loops will tend to accumulate and become rapidly fixed by natural selection. Additional variations and anomalies such as automimicry, chemical mimicry, sexual dimorphism and communication, selective sequestration and passing-up of allelochemicals, special glands and structures, and synergism effects, are among the secondary complications of this model that have occupied much thought, time, experimental labor, and polemical space in chemical ecology journals and meetings. Examination of the tendencies and results at various points in the model can be used to explain these features and to make further predictions, plan experiments, and devise activity-based bioassays and new chemical analyses. These may lead some day to new and more robust visions of the major patterns of chemical transfer at this widespread and important natural interface.     

Untangling the proximate causes and underlying drivers of deforestation and forest degradation in Myanmar

Political transitions often trigger substantial environmental changes. In particular, deforestation can result from the complex interplay among the components of a system—actors, institutions, and existing policies—adapting to new opportunities. A dynamic conceptual map of system components is particularly useful for systems in which multiple actors, each with different worldviews and motivations, may be simultaneously trying to alter different facets of the system, unaware of the impacts on other components. In Myanmar, a global biodiversity hotspot with the largest forest area in mainland Southeast Asia, ongoing political and economic reforms are likely to change the dynamics of deforestation drivers. A fundamental conceptual map of these dynamics is therefore a prerequisite for interventions to reduce deforestation. We used a system‐dynamics approach and causal‐network analysis to determine the proximate causes and underlying drivers of forest loss and degradation in Myanmar from 1995 to 2016 and to articulate the linkages among them. Proximate causes included infrastructure development, timber extraction, and agricultural expansion. These were stimulated primarily by formal agricultural, logging, mining, and hydropower concessions and economic investment and social issues relating to civil war and land tenure. Reform of land laws, the link between natural resource extraction and civil war, and the allocation of agricultural concessions will influence the extent of future forest loss and degradation in Myanmar. The causal‐network analysis identified priority areas for policy interventions, for example, creating a public registry of land‐concession holders to deter corruption in concession allocation. We recommend application of this analytical approach to other countries, particularly those undergoing political transition, to inform policy interventions to reduce forest loss and degradation.     

高原深水湖泊程海氮磷形态分布特征及其与叶绿素a的相关性

湖泊水体氮、磷形态分布特征及其与藻类生长的关系是湖泊富营养化研究的重要方面。采用GPS定位,在程海湖设置了3个断面9个采样点,研究了氮、磷形态分布特征,并分析了各形态氮磷与叶绿素a的相关性。结果表明：总氮（TN）质量浓度为0.773 mg.L-1,总磷（TP）质量浓度为0.046 mg.L-1,叶绿素a质量浓度为0.024 mg.L-1。氮素的赋存形态特征是以溶解态总氮（DTN）占大部分,DTN中又以溶解态有机氮（DON）占绝大部分;磷素的存在特点是溶解态无机磷（DIP）含量比重较大。各形态氮、磷都有明显的季节性波动但区域性差异不明显,叶绿素a则有明显的季节节律和时空差异。叶绿素a很好地响应了总氮（TN）、总磷（TP）、溶解态总氮（DTN）、溶解态总磷（DTP）、颗粒态总氮（PTN）、颗粒态总磷（PTP）的变化。程海富营养化受氮和磷共同限制,控制富营养化必须同时削减氮和磷。     

Ecotypes diversity in autumn olive (Elaeagnus umbellata Thunb): A single plant with multiple micronutrient genes

Elaeagnus umbellata, a member of the Elaeagnaceae family, is native to Pakistan, China, India, Korea, and Japan. It is found commonly at altitudes ranging from 1200 to 2100 m and thrives on eroded and degraded land due to its ability to fix nitrogen. The plant also grows under variable pH (4–8) and drought, and is used locally as fuel wood, fencing, fodder, basket making, and shelterbelts. The fruit of the plant is well known for its essential nutrients and medicinal compounds such as vitamins, minerals, essential fatty acids, carotenoids (lycopene), soluble solids, and sugars. Medicinally, it is widely believed to protect against myocardial infections, pulmonary infections, and various forms of cancers. Ten ecotypes from variable microclimatic conditions were investigated for their morphological, molecular and biochemical diversity improvement and commercialization purposes. Comparisons and disabilities indicated significant variability in terms of morphological (plant height, number of branches, thorn size and number, leaf area, fruit size, 100 fruit weight, and yield), molecular (SDS-PAGE), and micro- and macronutrient (vitamin C, Fe, mg, P, Na, K, essential oils, and sugar) bases among the ecotypes. This variability will be helpful in developing commercial varieties of the plant utilizing the conventional techniques of selection and hybridization for economic activities. The plant has ample quantities of multiple micronutrients, thus indicating their expression through a powerful promoter at one place (fruit mesocarp). Efforts to identify and isolate the micronutrient genes (vitamin A, C, E, and Fe), the deficiency of which causes malnutrition and disabilities within the population of developing countries. Micronutrient genes have also been initiated for their characterization and future transformation into staple food crops for stable bio-fortification.