典型土壤持久性有机污染物空间分布特征及环境行为研究进展

持久性有机污染物(POPs)由于具有致癌性、致畸性和致突变效应的"三致性",近年来已经越来越受到人们的关注.本文综合分析了有机氯农药(OCPs)、多氯联苯(PCBs)、二英类(PCDD/Fs)、多环芳烃(PAHs)及多溴联苯醚(PBDEs)等几种典型土壤持久性有机污染物的空间分布特征.同时,对土壤POPs的挥发作用、吸附/解吸、迁移、生物降解、化学降解等环境行为进行了深入分析,并指出了这些环境行为的影响因素,包括POPs的物质属性、土壤理化性质及周围环境等共性影响因素及其它因素.此外,针对国内外研究现状中存在的问题,提出了相关建议,指出控制土壤POPs污染的根本手段在于管理措施的完善.     

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.     

北江沉积物中多溴联苯醚的含量水平和分布特征

多溴联苯醚(PBDEs)具有与多氯联苯(PCBs)相似的化学结构和环境行为,是一种典型的持久性有机污染物(POPs).本文研究了珠江第二大水系北江流域沉积物中PBDEs的含量水平、空间分布特征和可能来源.     

多溴联苯醚在中国的污染现状研究进展

多溴联苯醚(Polybrominated diphenyl ethers,PBDEs)作为"新POPs"逐渐受到环境科研工作者的重视.本文综合评述了PBDEs在我国各种环境介质、生物体以及人体中的污染现状.研究分析表明,PBDEs在我国的污染尚处于相对较低的水平,但在广东贵屿和浙江台州等电子垃圾拆解地PBDEs的污染较为严重.本文最后展望了我国PBDEs研究中需要加强的几个方面.     

多溴联苯醚在啮齿类动物体内的代谢动力学研究进展

多溴联苯醚(PBDEs)是一类持久性有机污染物(POPs),其作为一种广泛使用的溴化阻燃剂在环境中普遍存在.PBDEs对生物体和人体存在内分泌干扰等毒性危害,正受到人们越来越多的关注.然而目前PBDEs对人体造成的影响都是由动物实验(主要是啮齿类动物)外推而得,因此研究不同的PBDEs同系物在啮齿类动物体内的代谢动力学...     

环境中多溴联苯醚分析方法的研究进展

多溴联苯醚(PBDEs)是一类性能优异的阻燃剂,被广泛添加到工业产品和日常生活用品中.研究表明很多PBDEs单体具有持久性有机污染物(POPs)的特性,其中五溴和八溴联苯醚已被列入POPs清单.它们在环境中广泛存在,对环境和生态系统带来健康风险.本文概述了环境中PBDEs的前处理方法和仪器分析的研究进展,对不同的方法进行了综述和比较,并提出了PBDEs分析方法研究的发展趋势.     

森林土壤中持久性有机污染物环境行为及其影响研究进展

持久性有机污染物(persistent organic pollutants, POPs)因其高毒、持久、生物积累、远距离迁移的特性而广受关注.森林土壤含有丰富的有机质,是POPs天然的储存库,对POPs的全球迁移与分配产生重要影响.森林土壤中POPs来源途径不仅包括POPs的干湿沉降,还存在着POPs随落叶迁移至森林土壤的特征途径.森林土壤富集大量POPs,有必要对其在土壤中的环境行为及其环境影响进行总结,因此本文从土-气交换、储存和迁移、降解转化等方面对POPs在森林土壤中的典型环境行为进行综述,分析其对森林土壤根际环境、微生物和微型动物以及食物链传递的环境影响,最后对森林土壤中POPs未来研究方向提出几点建议.     

中国海洋环境中卤代阻燃剂的污染现状与研究进展

卤代阻燃剂(halogenated flame retardants,HFRs)是具有持久性有机污染物(persistent organic pollutants,POPs)特性的一类化合物,它们广泛存在于海洋环境中,由于其具有环境持久性、长距离迁移性和生物富集性,HFRs的研究在近几十年来受到了极大重视.本文搜集了HFRs在中国海洋中的污染特征,其中包括多溴联苯醚(polybrominated diphenyl ethers,PBDEs)、六溴环十二烷(hexabromocyclododecane,HBCDs)、十溴二苯乙烷(decabromodiphenyl ethane,DBDPE)以及其他非多溴联苯醚(non-PBDEs)类HFRs在不同海洋介质中的含量水平与分布特征,并对HFRs在海洋中的生物富集和放大效应进行了综述.文章总结了中国海洋中HFRs相关研究存在的问题,包括缺少对新兴HFRs的报道以及现有研究区域有限等,并对今后的研究提出了建议.     

持久性有机污染物在食物链中积累与放大研究进展

研究持久性有机污染物(Persistent organic pollutants,POPs)在食物链中的积累与放大是进行环境风险评估和有效污染控制的生态学基础.本文综述了POPs的基本特征,POPs在食物链中的生物积累与放大的机制、影响因素以及POPs在食物链中积累与放大的模型等的研究进展.国外学者对POPs在水生食物链的积累与放大方面研究较多,并提出了较为完善的预测模型,而有关POPs在陆生食物链中的生物积累与放大的研究报道较少.大部分学者并未对完整食物链进行过系统而完整的研究.与国外相比,国内学者对POPs在水生陆生食物链中的生物积累、生物放大和预测模型探讨较少.目前POPs对环境和人体健康危害越来越严重,开展对POPs在食物链中积累、放大及相关预测模型更深入更完整的研究,已成为当前生态学和环境科学研究的重点课题和前沿领域.     

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。     

Reviewing the relevance of dioxin and PCB sources for food from animal origin and the need for their inventory,control and management

Background

In the past, cases of PCDD/F and PCB contamination exceeding limits in food from animal origin (eggs, meat or milk) were mainly caused by industrially produced feed. But in the last decade, exceedances of EU limit values were discovered more frequently for PCDD/Fs or dioxin-like(dl)-PCBs from free range chicken, sheep, and beef, often in the absence of any known contamination source.

Results

The German Environment Agency initiated a project to elucidate the entry of PCBs and PCDD/Fs in food related to environmental contamination. This paper summarizes the most important findings. Food products from farm animals sensitive to dioxin/PCB exposure—suckling calves and laying hens housed outdoor—can exceed EU maximum levels at soil concentrations that have previously been considered as safe. Maximum permitted levels can already be exceeded in beef/veal when soil is contaminated around 5 ng PCB-TEQ/kg dry matter (dm). For eggs/broiler, this can occur at a concentration of PCDD/Fs in soil below 5 ng PCDD/F–PCB-TEQ/kg dm. Egg consumers—especially young children—can easily exceed health-based guidance values (TDI). The soil–chicken egg exposure pathway is probably the most sensitive route for human exposure to both dl-PCBs and PCDD/Fs from soil and needs to be considered for soil guidelines. The study also found that calves from suckler cow herds are most prone to the impacts of dl-PCB contamination due to the excretion/accumulation via milk. PCB (and PCDD/F) intake for free-range cattle stems from feed and soil. Daily dl-PCB intake for suckler cow herds must in average be less than 2 ng PCB-TEQ/day. This translates to a maximum concentration in grass of 0.2 ng PCB-TEQ/kg dm which is less than 1/6 of the current EU maximum permitted level. This review compiles sources for PCDD/Fs and PCBs relevant to environmental contamination in respect to food safety. It also includes considerations on assessment of emerging POPs.

Conclusions

The major sources of PCDD/F and dl-PCB contamination of food of animal origin in Germany are (1) soils contaminated from past PCB and PCDD/F releases; (2) PCBs emitted from buildings and constructions; (3) PCBs present at farms. Impacted areas need to be assessed with respect to potential contamination of food-producing animals. Livestock management techniques can reduce exposure to PCDD/Fs and PCBs. Further research and regulatory action are needed to overcome gaps. Control and reduction measures are recommended for emission sources and new listed and emerging POPs to ensure food safety.

     

Too much of a good thing: on stoichiometrically balanced diets and maximal growth

Nutritional imbalances are of great interest in the ecological stoichiometry literature, in which researchers have focused almost exclusively on cases where nutrients are available in low amounts relative to energy (carbon), and animal growth is impaired due to insufficient nutrient intake. Little attention has been given to situations where food elemental content is higher than the level that satisfies animal requirements. However, most animals are strongly homeostatic with respect to the elemental composition of their body; hence they must excrete the excess of elements that are not in short supply. To date, stoichiometric theory has assumed that excretion of superfluous elements does not come with a cost and, thus, that consumption of food with surplus nutrients does not impair performance. Here we challenge this assumption, based on a compilation of several examples involving food phosphorus content that show that the performance of a wide variety of animals decreases when supplied with food containing high concentrations of (potentially) limiting nutrients. We discuss possible mechanisms for this phenomenon, and suggest that animals most vulnerable to effects of high food nutrient content are those that normally feed on low- quality (low-nutrient: C) food, and have a relatively low body nutrient content themselves, such as herbivores and detritivores.     

Food sharing by sibling vs nonsibling spiny mice (Acomys cahirinus)

Summary In comparison to paired unfamiliar unrelated age-mates, pairs of familiar littermate (sibling) spiny mice (Acomys cahirinus) were more active in exploring a novel environment containing limited food resources and engaged in a greater degree of cooperative feeding or food sharing. When animals born in successive litters were tested, however, familiar siblings did not differ from unfamiliar nonsiblings on measures of food sharing even though subsequent data indicate that such siblings could recognize one another. Young animals were found to feed for longer periods of time than their older cagemate regardless of whether the latter animal was a familiar sibling or an unfamiliar nonsibling.     

Fungal toxicity with special reference to mycotoxins

Mycotoxins are fungal secondary metabolites formed by consecutive series of enzyme-catalysed reactions from a few biochemically simple intermediates of primary metabolism. These mycotoxins can enter the human and animal food chain by direct or indirect contamination. Mycotoxins are equally harmful to animal and human beings. Realizing the importance of mycotoxins to the health of man and animals there have been concentrated efforts to develop highly sensitive analytical methods for detection and proper determination of mycotoxins in food, mixed feeds and feed ingredients, animal tissue, blood, urine and milk. Most of the mycotoxins are identified and most current research on it is concentrated on increasing sensitivity accuracy and reproducibility and above all to decrease the time of determination. A detailed review of mycotoxin and their detection is summarised in the paper.     

Polybrominated diphenyl ether (PBDE) levels in the blood of pure vegetarians (vegans)

Intake of many persistent organic pollutants (POPs) including dioxins, dibenzofurans and PCBs is almost exclusively from gastrointestinal ingestion of animal fats in the diet. With polybrominated diphenyl ether (PBDE) brominated flame retardants (BFRs), no consensus exists at present as to the extent of intake from food, from indoor dust or other routes of intake. Vegans, or pure vegetarians, were previously found to have low body burden of dioxins and dibenzofurans in blood. Data reported here for the first time show a trend towards lower PBDE levels with longer time periods without ingestion of food of animal origin in 8 adult residents of the United States. A stronger relationship between lower PBDE levels and time without meat, specifically, is consistent with substantial PBDE intake from meat relative to fish or dairy products in Americans. These vegans had somewhat lower PBDE levels with a range 12.4–127 and a median 23.9?ppb than published reports of US general population samples which had a range of 4–366 and median of 26?ppb. Our findings suggest that food of animal origin may be a major but not the sole contributor to human body burden of PBDEs.     

Sulfur isotopic variations in soft tissues of five benthic animals from the reductive,tidal-flat sediments in northern Kyushu,Japan

The sulfur nutrition of five benthic animals living in or on reductive, tidal-flat sediments has been studied by using the sulfur isotopic signatures of their soft tissues. The mean '³⁴S values (+6.1‰ to +13.8‰, relative to the Cañyon Diablo troilite reference) of these animals' tissues are lower than those of many common marine animals, which have values close to those of seawater sulfate-sulfur (+21‰). This indicates that these animals use a ³⁴S-depleted sulfur source, which may be derived from bacterial sulfide in the sediments (less than -20‰). The animals that inhabit such sediments are adapted to an anoxic environment, where toxic hydrogen sulfide prevails. Due to the sulfide-rich habitat, benthic animals are expected to assimilate hydrogen sulfide directly during detoxification, or to prefer a diet which has a low '³⁴S signature. Variations in '³⁴S values of the sampled molluscs were fairly small, whereas migratory shrimp and fish tended to have larger variations, implying that migratory animals feed on diverse prey, while the molluscs feed on a common food, or their assimilative capacity for sulfide-sulfur does not vary among individuals. A gastropod inhabiting the surface of the reductive sediment showed a distinctively low '³⁴S value (+5.8‰ to +6.4‰), indicating that the animal fed on detritus from reeds and halophytes with low '³⁴S values (-19.1‰ to -2.1‰). This study suggests that some benthic animals incorporate sulfide-sulfur for their nutrition and that sulfur isotope composition can be a useful indicator in the analysis of the food habitat of animals.     

Nebenprodukte der Lebensmittelverarbeitung als Futtermittel

The use of byproducts of the food industry as feedstuffs for animals has become a significant conflict for agriculture. Public regulations concerning the improvement of nutrient recycling and economic production with less financial support, on one hand, and the avoidance of all risks for human and animal health, on the other hand, are seen to affect agriculture practice. In this paper, information is presented about the quantities and quality of byproducts of the food industry used as feedstuffs. Also the nutritional and economical value of meat meal is discussed including ecological aspects. Other use or the disposal of products high in their nutritional value should, in the future, be no alternatives to the use as feed for animals, when risks are carefully controlled, because of the necessity for a sustainable agriculture and economy.     

Aufnahmepfade von POPs in Biota

POPs (persistent organic pollutants) associated with aquatic sediments can pose a risk to aquatic food chains, since they can be re-introduced to the food web. One major pathway is the bioaccumulation of POPs by endobenthic, sedimentingesting invertebrates (especially tubificid oligochaetes). These worms serve as food for benthivorous fish, which thereby ingest the sediment-borne chemicals and may accumulate contaminant concentrations far higher than from water exposure alone, and consequently transfer them to organisms of higher trophic levels. In order to evaluate such a potential biomagnification, a laboratory test was developed. It consisted of a two-step food chain including the sediment dwelling freshwater oligochaete Tubifex tubifex (Müller) and the three-spined stickleback (Gasterosteus aculeatus, Linné), a small teleost fish which often feeds primarily on benthic invertebrates. Artificial sediment and reconstituted water were used. To examine the influence of benthic prey on the bioaccumulation of a POP in the predator, fish were exposed to ¹⁴C-labelled hexachlorobenzene via spiked water, spiked sediment, pre-contaminated prey organisms, and to combinations of these exposure routes. Summarising the results of these experiments, it could be shown that the exposure to HCB via different routes resulted in a significantly higher accumulation in fish than an exposure to single pathways. It was concluded that the major uptake routes for fish were the overlying water and the food, whereas the contribution of spiked sediment itself was relatively small. HCB was biomagnified in the rested laboratory food chain. Therefore, concerning secondary poisoning, the environmental risk assessment of POPs like HCB should not be based on existing bioaccumulation tests alone, since they focus only on exposure via the water pathway. Instead, the influence of food and sediment as exposure routes should be considered as well, using comprehensive food chain modelling and/or laboratory studies.     

Advances on Toxicological Mechanism of AhR Pathway and Early Biomonitoring of Persistent Organic Pollutants (POPs)in Aquatic Animals

过去30年,随着工农业的不断发展,由持久性有机污染物(POPs)导致的癌症患者不断增加.目前POPs已广泛存在于水生态系统中,对水生动物的生长发育、种群繁衍、群落结构等产生重要影响.虽然POPs对水生动物的毒理机制非常复杂,但研究表明其毒理机制主要通过芳香烃受体通道(Ah Rpathway)来进行调控.为全面理解水生动物AhR通道中每一个基因在毒理调控过程中的作用,论文从水生动物芳香烃通道的角度详细阐述了POPs的毒理机制,同时对水生动物中POPs的早期监测进行了讨论,最后提出了未来POPs毒理机制研究的发展方向.