Rapid incorporation and short-term distribution of a nonylphenol isomer and the herbicide MCPA in soil-derived organo-clay complexes

Organo-clay complexes in soil are a major sink for xenobiotics and, thus, often enhance their persistence dramatically. However, the knowledge on environmental processes of non-extractable residue formation on a short time scale is very restricted. Therefore, this study examined the distribution of 4-(3,5-dimethylhept-3-yl)phenol (NP) and 4-chloro-2-methylphenoxyacetic acid (MCPA) in soil over a short time period of 48 h and in different soil sub-fractions. The overall proportion of organo-clay-associated bound residues was not only abundant but also in the same range for both substances (MCPA: 8%; NP: 11% of applied ¹⁴C-radioactivity). However, a more detailed view revealed two different distribution patterns: a higher proportion of clay-associated NP was accompanied by a lower content of bound residues, whereas a smaller fraction of clay-associated MCPA was characterized by a higher proportion of non-extractable residues. Further on, a selective accumulation of bound residues among clay-associated humic fractions was observed. NP residues were linked predominantly to humic acids, whereas MCPA residues tended to be incorporated more into fulvic acids. It was evident that the overall distribution was influenced primarily by the physico-chemical properties of the contaminants. This study demonstrates in detail a rapid initial incorporation accompanied by a specific distribution into soil sub-fractions for selected xenobiotics in soil and points to a complex interaction of clay-associated organic matter with low molecular weight compounds.     

土壤中结合残留态农药的生态环境效应

土壤中农药结合残留态的形成，导致其活性暂时降低，但并未从土壤中消失，在特定的环境条件下又重新释放到环境中并表现出较高的生物有效性，从而威胁农产品质量安全与环境质量。文章论述了土壤中结合残留态农药的定义、形成过程及影响因素、老化和释放过程及机制。土壤中结合残留态农药主要通过吸附过程、化学反应及物理镶嵌等作用而形成，其形成过程受农药的结构和化学特性、土壤理化性质、环境条件和农艺措施的影响。老化是化合物和土壤组分紧密结合，减少被普通提取方法提取出来的数量，降低了化合物的生物有效性。同时老化的物质在土壤环境条件改变的情况下又重新释放到土壤溶液中或进行矿化，此过程可以通过物理一化学机制或生物化学作用而发生。重新释放到环境中的结合残留态农药又表现出较高的生物有效性，可能被植物、动物或微生物所吸收，并沿食物链富集和放大或进入水体污染水产品和造成水质恶化，从而威胁人体健康。文章还分析了土壤结合残留态农药可能带来的环境问题，提出了此问题今后研究的方向。     

First evidence for a stereoselective incorporation of nonylphenol diastereomers in soil-derived organo-clay complexes

Environmental processes can affect the stereochemical properties of organic pollutants. In particular, biotic processes like microbial transformations or membrane penetration alter the ratios of enantiomers as well as diastereomers. These effects have been intensively used not only in environmental studies but also in medicine, toxicology, pharmacy, and agricultural sciences. However, in order to identify unambiguously biotic-initiated alteration of organic compounds, the knowledge on the stereoselective effect of all relevant processes is mandatory. Therefore, here we report the first evidence for a stereospecific formation of non-extractable residues of a xeniobiotic in a highly relevant soil subfraction, the organo-clay complexes. In this study, soils were spiked with labeled and unlabeled nonylphenol isomer, and incubation experiments were performed to study its long-term incorporation behavior into soil-derived organo-clay complexes under abiotic and biotic conditions. Besides the extractable particle-associated proportion especially the humic fractions comprising the bound residues have been analyzed by GC/MS. Our results from biotic experiments revealed alterations of the diastereomeric composition of the contaminant in the different soil humic subfractions. A depletion of the first eluting diastereomer as expressed by diastereomeric ratios around 0.6 has been observed for the extractable fraction, whereas the non-extractable proportion was enriched in the first diastereomer (diasteremoric ratio around 1.0). On the contrary, the diastereomeric ratios remained unaffected during the abiotic experiments (diasteremoric ratio around 0.8). These systematic observations give clear evidence that the process of microbial-assisted incorporation of nonylphenol into soil organo-clay complexes is a stereoselective process. To our knowledge, this is the first report on a stereoselective incorporation process of organic substances forming non-extractable residues. Consequently, the formation of non-extractable residues has to be considered in environmental studies dealing with stereoselective analysis of organic pollutants in soils to study their microbial transformation.     

四溴双酚A在土壤中的降解转化及残留研究进展

四溴双酚A (tetrabromobisphenol A,TBBPA)是全球生产量最大的溴代阻燃剂,广泛应用于电子产品和塑料等高分子材料的生产中.由于高的亲脂性及环境稳定性,TBBPA在土壤中易于累积.土壤作为污染物主要的汇之一,污染物在土壤中的环境过程和归趋对正确评价污染物的环境风险至关重要.本文综述了土壤中TBBPA在不同氧化还原条件(无氧条件,连续无氧-有氧条件和有氧条件)下、植物(芦苇和水稻)或蚯蚓(Metaphire guillelmi和Eisenia fetida)存在时的降解、矿化、代谢路径、不可提取态残留(non-extractable residues,NERs)形成和稳定性,以及相关微观机理.TBBPA在无氧条件下脱溴降解为双酚A,并稳定地存在于无氧土壤中.有氧土壤中的TBBPA经过甲基化、本位取代,以及烷基链断裂生成多种代谢产物.植物和蚯蚓会改变土壤中TBBPA的归趋,具体表现为明显降低TBBPA矿化,增加甲基化(形成更多甲基醚类代谢产物),减少NERs形成.TBBPA及其代谢产物可以和土壤中有机质以酯键和醚键的方式形成NERs.土壤氧化还原状态的改变会使NERs释放TBBPA及其代谢产物,但水稻根系分泌物添加到土壤中对NERs的释放没有显著影响.未来需要进一步研究TBBPA在土壤中转化的微生物学机制、土壤中NERs的形成机制、在生物体内的转化体制、以及土壤中不同形态NERs和生物体内NERs的稳定性和生物效应等,为全面准确评估TBBPA的环境风险提供科学依据.     

Remobilization of selected metal ions from Nile sediment (Egypt) according to sequential extraction and metal–EDTA complex

River sediments are basic components of our environment, providing nutrients for living organisms and serving as sinks for deleterious chemical species. The metal contents may be remobilized and released back into waters with changes in environmental conditions, thus affecting living organisms and human activities. This paper aims to determine the effect of a synthetic anthropogenic chelating agent (EDTA) as industrial discharges on the remobilization of several metals (Cu, Zn, Cd, and Pb) in River Nile sediments (at Aswan and Mansoura cities) under different concentrations and pH values, and to investigate the influence of metal–EDTA complexes on this remobilization. For these purposes, sequential extraction and experiments on the effect of pH and metal EDTA complex were carried out on the two representative sediment samples south and north of the River Nile in Egypt. The results of sequential extraction show that most of metal contents present in the residual form (Cu, 11.36–72.34%; Pb, 29.64–66.67%; and Zn, 43.76–50.09% at Aswan and Mansoura, respectively). Non-residual fractions which may be available for the remobilization by EDTA represented anthropogenic (industrial, agriculture, and domestic discharges) and lithiopogenic (metals bound to Fe and Mn oxides) sources. A clear increase was detected for Cu and Zn remobilization from the increase in EDTA concentrations, in contrast, Cd independent of the EDTA concentration and slight influence on Pb content. The remobilization of metals as a function of pH exhibited. The metals were greatly remobilized under the complexing action of EDTA, showing that some of these elements were adsorbed on the sediments. The remobilization rate of metals was dependent upon the added metal–EDTA complex (with the exchange rate being in the order Ca–EDTA>Zn–EDTA>Cd–EDTA>Cu–EDTA>Pb–EDTA), due to the stability constant of the metal–EDTA complex. The results of these experiments showed that heavy metals are greatly remobilized under the complexing action of EDTA when it is present in excess, so all precautions should be taken to prevent any wastewater containing EDTA or any chelating agents discharging directly or indirectly via the River Nile stream because most EDTA remains in the aquatic phase. The ability of this portion to remobilize metals from sediments should be taken into account.     

Blue-winged warblers (Vermivora pinus) “recognize” dialects in type II but not type I songs

Summary Male blue-winged warblers (Vermivora pinus) sing two distinctly different song types (I and II). Type II songs from eastern New York and western Massachusetts, USA, are different (Fig. 1), and during playback experiments males respond stronger to local than to foreign songs (Fig. 2). Type I songs are more stereotyped geographically (Fig. 1), and males do not differentiate between local and foreign Type I songs (Fig. 3). Differing degrees of intra- and inter-sexual selection on these two forms may have promoted variability in Type II songs and stereotypy in Type I songs among locations.     

Grundwasserbelastung durch Rüstungsaltlast-Emissionen

Groundwater analyses in the area of the former munitions depository (World War II) ?Dethlinger Teich“ near Munster/Niedersachsen were evaluated. Results from 50 different chemical substances showed that arsenic compounds are the main contaminating chemicals. A new method has been developed to distinguish between morganically- and organically bound compounds. This differentiation is required for risk assessment and evaluation. Also, the relationship of chemical structure and physiological effects in organo arsenic compounds is described.     

Bt作物杀虫蛋白在农田土壤中残留动态的研究进展

综述了转Bt作物释放的杀虫蛋白在农田土壤中的残留动态．重点阐述了：①土壤中Bt毒素蛋白的检测方法；②Bt毒素在土壤中残留、富集与降解动态；③Bt毒素蛋白与土壤中具有表面活性颗粒的吸附结合规律；④土壤中Bt毒素的杀虫活性．国内外研究结果表明，转基因植物释放到土壤中的Bt毒素蛋白迅速与土壤中具有表面活性的颗粒吸附并紧密结合，降低生物降解，但结合后的Bt毒素结构没有改变，致使毒素蛋白在土壤中长期滞留并保持其杀虫活性，可能会对土壤中非靶标生物造成不良影响．因此深入、系统地研究和评价转Bt作物释放的Bt毒素对土壤生态系统的风险迫在眉睫．参50     

危险化学品泄漏入海区域风险评估方法研究

我国的危险化学品区域风险评估研究工作起步较晚,针对危险化学品泄漏入海的方法研究较少。现有区域风险评估方法中评估对象多为单一风险因素,存在着未全面考虑研究区域内其他风险源和敏感资源等综合影响的不足。在结合国内外研究进展现状的基础上,强化与相关技术方法的衔接,建立了综合考虑危险化学品危险性和区域风险承受力等因素的危险化学品泄漏入海区域风险评估方法工作,并选择天津市XX企业开展方法案例应用。本研究能够为科学合理划分危险化学品泄漏区域海洋环境风险等级提供技术支撑,为开展危险化学品泄漏入海风险防范和修复评估等工作提供决策依据。     

Bewertungsmaßstäbe zur Beurteilung von Schadstoffbelastungen in Böden anhand der Bioverfügbarkeit

Until now, assessment of contaminated sites is based on variable protection goals, whereby total contents and in part mobile contents are considered. Due to interactions of pollutants in soil and bound residues, total contents do not reflect the actual risk. In contrast an investigation based on availability/bioavailability of contaminants would enable a harmonization of the protection-goal-based evaluation and a closer-to-reality risk assessment for the individual location.     

Tumor-like formations on the shells of Japanese scallops Patinopecten yessoensis (Jay)

Three types of tumor-like formations on the shell of commercial Japanese scallop Patinopecten (= Mizuhopecten) yessoensis were identified. The first type of tumor-like formation (Type I) is a brown prominent knob on the inner shell surface. This is the result of penetration of aggregations of the polychaete worms of genus Polydora into the scallop cavity usually through the upper valve of scallop and subsequent covering of their boreholes by shell calcite carbonate. The second type (Type II) is tumor-like lamination of the shell with the inclusion of organic matter between calcite layers on the inner surface of the upper and lower valves. These laminations have no outlet to the outer shell surface. The third type of scallop shell tumor-like lesion (Type III) mainly built up on the inner surface of the lower valve. It is a cone-shaped lump, which seemed to consist of aggregated coarse-grained sand. It has no outlet to the outer shell surface. Tumors of the different types are not equally distributed. Type I tumors are the most common, followed by Type II and Type III. Other kinds of tumor-like lesions on the inner shell surface are not found in the species studied. On the outer surface of scallop shell tumor-like formations were not found. The shell tumor-like lesions occurred significantly more frequently on scallops that are inhabiting muddy bottom sediments than sand. A positive relationship was found between scallop age and occurrence of shell lesions. The tumor-like formations of all types adversely influence scallops. The shell height and total, soft tissue and adductor muscle weights were lower for scallops with tumor-like formations on the shell than for healthy individuals.     

PSM in Böden:

The fate of pesticides in soil is incompletely described by the analytical determination of applied pesticides because a differentiation between the processes degradation and sorption which determine pesticide concentration in soils is not possible. By analyzing corresponding metabolites, degradation can be confirmed. Detailed mass balances considering the mineralization and formation of non-extractable residues are set up in closed model systems applying radiotracer techniques. This complex laboratory data can only be transferred to field conditions by mathematical modeling.     

OECD鱼类生物蓄积测试的优化策略研究

作为化学品风险管理中的重要环境行为参数,生物蓄积性不仅是分类、标签、评价和控制环境风险的基本指标,也是鉴别化学物质持久性和环境危害性的重要标准。2012年OECD颁布了新的生物蓄积测试方法,由此给生物蓄积优化策略带来了全新的挑战,原有的判别优化策略的方法需要作出新的发展与调整。针对新生物蓄积测试方法引发的优化策略挑战,通过层次研究及文献分析,归纳了基于OECD新305生物蓄积测试标准的优化测试策略,为优化、简化测试及化学品安全管理提供了科学基础。     

Origin and development of the amoebocytes of Nicolea zostericola (Polychaeta: Terebellidae) with a discussion of their possible role in oogenesis

Three types of amoebocytes are present at different stages in the life history of Nicolea zostericola (Grube, 1860): a granular amoebocyte or spindle cell and 2 agranular amoebocytes, designated Type I and Type II. The agranular amoebocytes originate from specific sites on the lateral parietal peritoneum of the coelomic cavity in all the thoracic and a few abdominal segments. The origin of the granular amoebocyte is unknown. In juvenile worms the Type I amoebocyte enters the coelomic fluid and accumulates lipid and glycogen, presumably derived from reserves stored in the parietal peritoneum. Near the beginning of the vitellogenic phase of oogenesis, the Type I amoebocyte disappears and a Type II form is produced by the peritoneum. Type II cells differ cytologically from the Type I form by containing extensive rough ER (endoplasmic reticulum), Golgi complexes and free ribosomes; they appear to synthesize protein for export. At the end of vitellogenesis and near spawning, amoebocytes undergo alterations which include the migration of the nucleus to a central position, the formation of stacks and whirls of rough ER cisternae, and the appearance of vacuoles throughout the cytoplasm. It is suggested that the agranular amoebocytes obtain nutrients from food reserves stored in the parietal peritoneum and transfer them to the oocytes for use in yolk synthesis. The function of the granular amoebocytes is unknown.Contribution No.37 from the Marine Science Institute, Northeastern University, Nahant, Massachusetts, USA.Contribution No. 50, Harbor Branch Foundation, Inc.     

The metabolism and distribution of [14C‐phenyl]‐ethyl parathion in a tropical soil under field conditions

The persistence, distribution and metabolism of [^l4C‐phenyl]‐ethyl parathion applied to soil columns in an agricultural farm were investigated under tropical field conditions. Volatilization, soil microbial activity, moisture levels and pH were found to influence the persistence, distribution and metabolism of this pesticide in the soil. There was rapid distribution of the pesticide in the soil matrix with time resulting in high levels of bound residues which reduced the overall rate of disappearance of parathion residues from the soil. The soil was slightly acidic but the metabolites, paraoxon, p‐nitrophenol and p‐aminophenol were detected in the soil extracts 7 days after pesticide application. After 72 days, 43.7% of the applied pesticide remained in soil composed of 18.9% extractable and 24.8% bound residues. A mechanism for the metabolism of ethyl parathion in this soil is given.     

根际环境对除草剂扑草净环境归趋的影响评价

植物保护产品（PPP）需要经过严格的监管评估，以确保它们不会对环境造成不可接受的风险。阐明化学品在土壤中的命运和行为是环境风险评估的一个组成部分。土壤中PPP活性物质降解首先在实验室研究中进行评估（通常遵循OECD 307实验导则）。但指导性实验室研究中的条件与农业使用中的条件相差甚远，而目前还没有评估作物根系的贡献。在这里，我们将代表三种不同作物类型的有效植物根系整合到OECD 307实验设计中，以评估它们对除草剂PPP降解的影响。在所有三种种植体系中，母本残留的下降速度和不可提取残留的形成速度都显著加快。这导致50%降解时间（DT50）在黑麦草和辣椒的存在下降低约一半，在红三叶的存在下减少约三分之一。这些发现表明植物及其相关的根系网络对PPP降解有显著影响。基于这些数据，需要将植物根系纳入更高层次的研究，在标准化实验室研究设计中增加更大的环境现实性，进而有助于改进环境风险评估过程。     

Light-dependency of nitrate uptake by phytoplankton over the spring bloom in Auke Bay,Alaska

The effect of light intensity on nitrate uptake by natural populations of phytoplankton was examined by ¹⁵N traceruptake experiments during the spring (March–May 1987) in Auke Bay, Alaska. The data were fit to a rectangular hyperbolic model which included a term for dark uptake. Three types of curves described nitrate uptake as a function of light intensity. The first (Type I) had a low half-saturation light intensity (K _I), low chlorophyll-specific uptakes rates, no dark uptake and occasional photoinhibition. These were observed during a period of biomass decrease, accompanied by low daily light and strong wind, prior to the major bloom. The second type (Type II) had relatively high K _I, high chlorophyll-specific uptake rates, and no dark uptake. Type II curves were observed during most of the period prior to nitrate depletion in the surface waters. Types I and II both appeared prior to nitrate depletion in the water and reflected variations in the light history of the phytoplankton population. The third type (Type III) occurred in nitrate-deplete conditions, when nitrate uptake was less dependent on light intensity (i.e., high rates of dark uptake and lower K _I). Decreased light-dependency during this period was coupled with physiological nitrogen deficiency in the population. Comparing these parameters to those of photosynthetic carbon fixation, K _Ivalues of nitrate uptake were generally higher than those of photosynthesis prior to nitrate depletion, and lower during nutrient-deplete conditions.     

超临界流体萃取在研究土壤和沉积物结合态残留中的应用

许多有机污染物在土壤和沉积物中形成持久稳定的结合态残留；结合态残留对土壤和沉积物的解毒过程、污染物长期分配行为、生物可用性和生物毒性都具有重要影响。为了揭示结合态残留的形成机制及其对污染物环境行为和毒理学参数的影响，从土壤或沉积物中提取出不同结合状态的有机污染物就显得非常重要。超临界流体萃取(SFE)可以实现选择性萃取，从而得到有关污染物一基体间相互作用的信息。文章介绍了SFE应用类型、超临界流体种类以及影响SFE萃取率的因素，对SFE模拟有机污染物长期吸附／解吸行为和生物可用性研究进行了论述，并认为SFE势必发展成为土壤或沉积物中结合态残留形成机理研究、土壤修复和生态风险评价的一种强有力的技术。     

Dark survival strategies in marine phytoplankton assessed by cytometric measurement of metabolic activity with fluorescein diacetate

Cytometric quantification of cellular fluorescence upon cleavage of fluorescein diacetate (FDA) is presented as a sensitive and rapid technique to assess phytoplankton metabolic activity during exposure to prolonged darkness of 10 to 12 d. Two distinct types of metabolic response to darkness are distinguished: Type I cells (Brachiomonas submarina, Pavlova lutheri, Chrysochromulina hirta) adapt to prolonged darkness by reducing their metabolism to a lower level of activity (∼10% of initial in P. lutheri, C. hirta, ∼0.5% in B. submarina) within few days, whereas Type II cells (Prymnesium parvum, Bacteriastrum sp., unidentified pennate diatom) continue with unchanged activity. Type I cells were able to maintain their initial cell abundance and commenced rapid cell growth upon re-illumination after 12 d of darkness. Among Type II cells, diatoms were able to maintain cell abundance and growth capacity as well, whereas P. parvum was not. Type I cells are expected to exhibit competitive advantages in environments with frequent or long dark periods. Bacterivory further supports dark survival in C. hirta. Received: 10 May 1999 / Accepted: 20 September 1999     

Colonization of Europe by two American genetic types or species of the genus Marenzelleria (Polychaeta: Spionidae). An electrophoretic analysis of allozymes

Allozyme electrophoresis was conducted in an attempt to identify the origin ofMarenzelleria sp. found in the North Sea and Baltic Sea. The analysis covered eight enzymes with ten loti from nine populations found on the North American Atlantic toast, these populations in the North Sea and five populations in the Baltic. The North Sea spionids correspond to the Type IMarenzelleria from North American coastal waters between Barnstable Harbor (Massachusetts) and Cape Henlopen (Delaware). Nei's genetic distance between these North American populations and those from the North Sea wasD = 0.010 to 0.020. TheMarenzelleria sp. found in the Baltic Sea very probably stems from North American populations of Type II found from the region of Chesapeake Bay (Trippe Bay) south to the Currituck Sound (North Carolina). The genetic distance between these North American populations and the Baltic populations isD = 0.000 to 0.001. The invaders appear to have lost little of their genetic variation while colonizing the North and Baltic Seas. Probably, both colonizing events tan be attributed to large numbers of individuals reaching Europe simultaneously on one or more occasions. In addition, aMarenzelleria Type III was found by electrophoresis among specimens from Currituck Sound (North Carolina), rohere it is sympatric withMarenzelleria Type II. Salinity is discussed as an important factor for the establishment ofMarenzelleria Type I in the North Sea and Type II in the Baltic Sea.