有机污染物对发光菌和鱼的毒性相关性研究

研究有机污染物对不同水生生物毒性的种间关系有助于探讨有机污染物对水生生物的毒性作用模式。本文应用1 470种有机化合物对发光菌的毒性数据和949种有机化合物对鱼的毒性数据,研究有机化合物对发光菌和鱼的种间毒性作用模式。结果表明,有机化合物对发光菌和鱼的毒性呈正相关,但种间相关性较差。通过计算毒性比率TR值表明多数类别有机化合物具有相似的种间毒性作用模式。基线和弱惰性化合物对发光菌和鱼的毒性均与辛醇水分配系数log Kow具有良好的线性关系,这说明基线和弱惰性化合物在发光菌和鱼体内的残余量CBR值均为一个常数。这些化合物对发光菌和鱼具有相似的毒性作用模式和生物吸收过程。另外,一些亲水性化合物的log TR值具有较大的种间差异,即对发光菌和鱼的毒性效应具有较大的种间差异,表明亲水性化合物对发光菌为反应型化合物,而对鱼为麻醉型化合物。有机化合物对发光菌和鱼的毒性种间相关性通过引入疏水性参数得到了一定的改善,这表明这些亲水性化合物毒性效应的种间差异有一部分归因于有机化合物在发光菌和鱼体内的生物富集不同,而不是由于与生物分子的反应性不同。这些亲水性化合物相对于鱼的腮和皮肤更容易通过发光菌的细胞膜,与生物分子发生化学反应,从而具有较高的毒性效应。Log Kow大于7的化合物对发光菌和鱼均具有较低的毒性,说明有机化合物在生物体内的富集能力对有机化合物剩余毒性的判别起着重要作用。     

氯代多环芳烃的污染现状及毒性研究进展

氯代多环芳烃(chlorinated polycyclic aromatic hydrocarbons,Cl-PAHs)是一种多环芳烃的氯代衍生物,具有与二噁英相似的毒性效应,并且在各种环境介质中广泛存在。Cl-PAHs已成为一种新型有机污染物,对生态环境和人体健康造成潜在的威胁。本文从Cl-PAHs的来源、污染现状、毒性效应与人体健康风险评价等几个方面对国内外有关Cl-PAHs的研究现状和最新进展进行了系统综述。     

Levels and congener distributions of PCDDs,PCDFs and dioxin-like PCBs in environmental and human samples: a review

The term “dioxins” is often used in a confusing way. In toxicological considerations—and also in the present report—the term is used to designate the PCDDs, the PCDFs and the coplanar (“dioxin-like”) PCBs, since these classes of compounds show the same type of toxicity. Because of the large number of congeners, relevant individual congeners are assigned with a toxic equivalency factor (TEF) that relate their toxicity to that of tetrachlorodibenzo-p-dioxin (TCDD) (2,3,7,8-TCDD) and are to be evaluated as dioxins. Each concentration of an individual congener in a mixture is multiplied with its TEF, and the resulting TCDD equivalents are added up and expressed as WHO-endorsed toxic equivalents (WHO-TEQ). Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are mainly the by-products of industrial processes (such as metallurgical processing, bleaching of paper pulp, and the manufacturing of some herbicides and pesticides) but they can also result from natural processes like volcanic eruptions and forest fires. Waste incineration, particularly if combustion is incomplete, is among the largest contributors to the release of PCDDs and PCDFs into the environment. Due to their persistence, PCDDs, PCDFs and PCBs are part of the so-called persistent organic pollutants group of compounds that also include some chlorinated pesticides. Since they have a high lipophilicity and resist transformation, they bio-accumulate in animal and human adipose tissues. Consumption of food is considered as the major source of non-occupational human exposure to PCDD/Fs with foodstuffs from animal origin accounting for more than 90% of the human body burden. With meat, dairy, and fish products being the main contributors. The aim of the present review was to summarize experimental data regarding dioxin emissions from contaminated and uncontaminated biological and environmental samples, from the available literature. The information will be presented chronologically with respect to distribution in human milk, serum; food, water, air, soils and sediments.     

Assessment of toxicity of two nitroaromatic compounds in the freshwater fish Cyprinus carpio

This study was conducted to evaluate the toxicological response of p-nitrotoluene and p-nitroaniline to the key fish species, Cyprinus carpio. A freshwater fish bioassay based on the 96 h LC ₅₀ was used to estimate the single and joint toxicity of the two chemicals. The toxicity of p-nitrotoluene was greater than that of p-nitroaniline based on 96 h LC ₅₀ values of 40.74 mg·L^?1 and 48.99 mg·L^?1, respectively. Both compounds had moderate toxicity toward Cyprinus carpio, and this toxicity increased with the exposure duration and concentration. Binary mixtures of the compounds were more toxic than the individual compounds at 96 h, and they acted upon partial addition. When the exposure time was longer, the toxicity increased for mixtures of compounds with the same concentration or toxicity. The results of this study suggest that exposure to a combination of these chemicals would result in a higher environmental risk in aquatic systems than exposure to either compound alone. Further research is needed to investigate the combined effects and sublethal toxicity of p-nitrotoluene and p-nitroaniline, since they are both still used in China.     

农药类化合物对大型溞的毒性作用模式:与基线毒性化合物比较研究

农药在控制有害生物的同时,对水生生态系统产生较大的毒性效应。本文通过实验获得了25种基线化合物对大型溞的急性毒性数据,并与57种农药类化合物对大型溞的急性毒性数据进行比较研究,同时根据体外浓度LC_(50)、生物富集因子BCF和体内临界浓度CBR的关系,计算了这些化合物在大型溞体内的临界浓度,研究了农药类化合物对大型溞的毒性作用机理。结果表明,基线化合物在大型溞体内的临界浓度log1/CBR值在一个很窄的范围波动,而农药类化合物在大型溞体内的临界浓度log1/CBR值范围广且较高。这说明多数农药类化合物对大型溞为反应性毒性作用模式。其中,除草剂对大型溞的毒性显著低于杀菌剂和杀虫剂对大型溞的毒性。这可能是因为除草剂主要通过干扰植物光合作用、植物激素或植物分子合成发挥毒性效应,从而导致其对大型溞的生理系统难以发生反应性毒性效应。而杀虫剂和杀菌剂主要通过干扰生物神经系统、生殖系统、呼吸作用或大分子合成发挥毒性效应,因此易与大型溞生理系统发生生物化学反应,从而具有较高的毒性效应。本文分别建立了除草剂、杀菌剂和杀虫剂对大型溞的急性毒性QSAR模型。除草剂对大型溞的急性毒性机理较简单,其毒性与化合物疏水性程度和离子化程度有关;而杀菌剂对大型溞的急性毒性主要与化合物的标准生成热和极性表面积有关;杀虫剂对大型溞的急性毒性作用机理较复杂,它们对大型溞的毒性效应与其和生物分子之间的氢键和范德华力有关。     

含氯苯酚类化合物结构表征与毒性预测

将有机化合物中的不同非氢原子及非氢原子之间的关系参数化得到新的结构描述符,运用该描述符对部分含氯苯酚类化合物分子结构进行了参数化表征。采用偏最小二乘回归(PLS)方法构建了化合物结构与毒性(-lg IC50)之间的关系模型,模型的建模相关系数(R2)为0.948,"留一法"交互检验的相关系数(Q2)为0.922,标准偏差(SD)为0.184。结果表明结构描述符能较好地表征化合物分子结构特征,所建模型稳定性好、预测能力强,对于酚类化合物QSAR研究具有一定的参考价值。     

利用前线分子轨道能预测有机物生物毒性的方法

本文以线性自由能理论为基础提出了一种利用分子轨道能预测有机物生物毒性的方法，并利用这种方法建立了预测氯代芳烃化合物发光菌毒性的定量相关方程。     

In vitro evaluation of atmospheric particulate matter and sedimentation particles using yeast bioassay system.

Little information on the evaluation of airborne particulate matter (APM) and sedimentation particles from subway stations is available. The thermal metamorphism of train wheels generating toxic particles in subway stations is a possibility. In this study, the toxicity and physiological effects of particles from subway stations were evaluated using a yeast bioassay system. Estrogenic and antiestrogenic activities of APM in APM extracts from subway stations were determined. No estrogenic activity was found in the APM fractions and their S9-activated APM samples. Sedimentation dust samples also showed no estrogen activity. In contrast, extracts from sedimentation dust samples showed antiestrogen activity. Marked yeast toxicity was observed in the samples extracted from sedimentation dust. Potent yeast toxicity was also found in the S9-activated extracts from sedimentation dust. The results suggest that sedimentation dust from a semiclosed area of a subway system has antiestrogen activity, although both the origin and generation system of this activity are uncertain. These pollutants in sedimentation dust may change to a more toxic form in vivo by S9 activation.     

Acute toxicity of 30 pharmaceutically active compounds to freshwater planarians,Dugesia japonica

Pharmaceutically active compounds are produced worldwide and consumed in large quantities, so these chemicals are frequently detected in limnic environments posing potential ecological risks. Thirty pharmaceutically active compounds were selected for examination of their acute toxicity for freshwater planarians (Dugesia japonica). Among the 30 compounds tested, diclofenac, mefenamic acid, naproxen, propranolol HCl, and diphenhydramine HCl had a 48-h nominal LC₅₀ below10 mg L^?1, and for 18 chemicals, it exceeded 100 mg L^?1. The 96-h nominal LC₅₀ was below 10 mg L^?1 for diclofenac, mefenamic acid, naproxen, propranolol HCl, diltiazem HCl, diphenhydramine HCl, hydroxyzine HCl, and triprolidine HCl, and for 15 chemicals, it exceeded 100 mg L^?1. Among different therapeutic groups, analgesics were most toxic to planarians, and antibiotics were least toxic. Antihistamines and beta blockers varied in their acute toxicity to planarians. At the current environmental levels, none of the tested pharmaceutically active compounds may have acutely harmful impacts on aquatic invertebrates. To answer the question whether chronic, long-term exposure to pharmaceutically active compounds may entail ecological risks for aquatic ecosystems, further investigations with different end points in multiple species tests are needed.     

Screening for acute ocular toxicity of commercialized products of cartap,an insecticide,and correlation to blood concentrations in rabbits

Cartap is an insecticide known to produce contraction and damage to mouse and rabbit diaphragms, and plays a pivotal role in respiratory paralysis and mortality in rabbits. The aim of this study was conducted to screen for the toxic properties and blood concentrations of commercialized cartap products in New Zealand White (NZW) rabbits. Five granular formulations (GRs) with different concentrations (4, 6, 6.5, 6.66 or 10%) and seven water-soluble powders (SPs, 50%) of commercialized cartap products were chosen to study toxicity following ocular instillation. Furthermore, ocular instillation (5, 12.5, 25 or 50 mg kg^?1) and oral administration (25 mg kg^?1) of the technical material (TC) cartap was also performed to compare blood concentration changes in rabbits. There was no death or eye irritation with all GR products; however, soluble powder (SP) products produced severe toxicity and mortality in rabbits. The blood concentration of TC cartap in rabbits started to increase from 2 min and reached peak levels at 7–9 min after ocular instillation in a dose-related pattern. For comparison of the blood distribution of cartap via different administration routes, oral exposure exhibited a higher absorption of cartap than ocular instillation. It was suggested that the commercialized GR products of cartap were safe but 50% SP products were highly toxic to rabbits following ocular exposure. This study provides valuable data to screen for potential acute toxicity of cartap to farmers and animals in the field.     

Heavy metals and marine diatoms: Influence of dissolved organic compounds on toxicity and selection for metal tolerance among four species

Experiments were conducted to determine whether diatom clones isolated from waters (Corio Bay or Hobson's Bay, Australia) chronically contaminated with heavy metals were more metal-resistant than clones of the same species isolated from cleaner waters (Bass Strait). Four species (2 clones per species) and 3 metals (Cu, Zn, Cd) were examined. The growth response of each clone to metal additions was assessed in both Corio Bay water and Bass Strait water. Generally, Cu was readily chelated and the most toxic metal and Cd the least chelated and least toxic. Toxicity of Cu to growth was found to be directly related to cellular Cu levels, which in turn were mediated by dissolved organic compounds in seawater. Corio Bay water had a greater metal-complexing capacity than Bass Strait water, and metal additions generally proved more toxic to each clone when in Bass Strait water. Ultraviolet irradiation eliminated differences between the water types. Relative to Bass Strait clones, no trend of enhanced metal tolerance was noted among the Corio Bay and Hobson's Bay clones; on the contrary the Corio Bay and Hobson's Bay cells were generally less to lerant of metals than were their Bass Strait counterparts, being particularly affected when in Bass Strait water. The results suggest that metal additions to waters rich in dissolved organic compounds would likely have less effect (in terms of direct toxicity and as a selective agent for metal tolerance) on resident phytoplankters than similar additions to waters low in organics.Publication No. 274 in the Ministry for Conservation, Environmental Studies Series     

含氯苯酚类化合物结构表征与毒性预测

将有机化合物中的不同非氢原子及非氢原子之间的关系参数化得到新的结构描述符，运用该描述符对部分含氯苯酚类化合物分子结构进行了参数化表征。采用偏最小二乘回归(PLS)方法构建了化合物结构与毒性(-lgIC₅₀)之间的关系模型，模型的建模相关系数(R²)为0.948，“留一法”交互检验的相关系数(Q²)为0.922，标准偏差(SD)为0.184。结果表明结构描述符能较好地表征化合物分子结构特征，所建模型稳定性好、预测能力强，对于酚类化合物QSAR研究具有一定的参考价值。     

Assessing the toxicity of chemical compounds associated with marine land-based fish farms: The use of mini-scale microalgal toxicity tests

Many chemicals that are currently used in aquaculture have not been evaluated with regard to their specific effects on the aquatic environment. In the present study, the toxic effects of several chemicals associated with land-based marine fish farming activities were assessed using two species of marine microalgae (Phaeodactylum tricornutum and Isochrysis galbana). Mini-scale toxicity tests were performed with six antibiotics (amoxicillin, ampicillin, flumequine, oxytetracycline, streptomycin and sulfadiazine) and two disinfectants (formaldehyde and hypochlorite). Amoxicillin and streptomycin did not exert toxic effects. Sulfadiazine was the most toxic chemical; the EC₅₀ values were 0.11 mg/L and 1.44 mg/L for P. tricornutum and I. galbana respectively. As expected, the disinfectants displayed high toxicity, and P. tricornutum was particularly sensitive to these compounds. Although the differences in microalgal sensitivity depended on the chemical considered, both species were highly sensitive to most of the compounds tested. We recommend the inclusion of mini-scale microalgal toxicity tests in environmental risk assessment (ERA) and environmental monitoring plans because they are cost-effective and rapid.     

White blood cell sister chromatid exchange among a sample of Thai subjects exposed to lead: Lead-induced genotoxicity

Epidemiological and experimental studies indicated that inorganic lead compounds are associated with increased risks of tumorigenesis. This study was aimed at determination for sister chromatid exchange (SCE), a marker for genotoxicity with correlation to lead blood levels in Thai exposed subjects. A total of 32 police (all males) were included into this study. The average (mean ± SD) blood lead in these police was 2.1 ± 1 µmol L^?1. The average SCE among the police with high blood lead was significant higher than those with low metal exposure. Data suggest that cytogenetic response to Pb is significantly different between the subjects with high versus low lead exposure. High exposure to lead seems related to high chromosome aberrations.     

Hazardous halogenated substances formed during combustion processes

The results of the emissions from combustion processes and/or from fire accidents show the risk to man and his environment and thus the need for strict legislation and critical analysis of unwanted compounds. These substances or their thermolysis products are often due to incomplete combustion or may result from the interaction of various substances.

In the following we report the formation of octachlorostyrene (OCS) and of high‐toxic substances such as polybrominated dioxins (PBrDD's), dibenzofurans (PBrDF's) by the combustion.

In order to determine a possible source of the non‐manufactured compound OCS, we conducted several model experiments in a combustion chamber at various temperatures from 400 °C to 800 °C. The thermolysis of chlorinated solvents like chloroform or of chlorinated aromatice like pentachlorobenzene produced—among other chlorinated substances—OCS as one of the major products.

Analogous combustion experiments with polyester plastics containing decabromodiphenylether as flame retardant and antimony trioxide as Synergist led to PBrDD's and PBrDF's. Here antimony trioxide seems to play an important role because in absence of this oxide, PBrDD's and PBrDF's were not found in our experimental conditions.     

Toxic phytoplankton blooms in the southwestern Gulf of Maine: testing hypotheses of physical control using historical data

Blooms of the toxic dinoflagellate Alexandrium tamarense Lebour have been nearly annual features along the coasts of southern Maine, New Hampshire and Massachusetts, USA, since 1972. In 1990 two hypotheses which have been used to explain the initiation of these blooms in the southwestern portion of the Gulf of Maine were tested using historical records of shellfish toxicity, wind, and river flow. The first hypothesis states that the blooms were initiated or advected to shore by wind-driven coastal upwelling. The second states that established blooms were advected from north to south alongshore in a coastally trapped buoyant plume of water. Of the eleven years examined (1979 to 1989), we found seven cases inconsistent with the wind-driven upwelling hypothesis, and only one case (1985) which contradicts the plume-advection hypothesis. 1985 was an unusual year in many respects, and we suggest that some other mechanism was responsible for the toxic outbreaks. In addition, the wind-driven upwelling hypothesis could not explain the observed north-to-south temporal progression of toxicity each year. The plume-advection hypothesis was found to best explain the datails of the timing and spread of shellfish toxicity in Gulf of Maine waters to the south of Penobscot Bay, Maine. These include the variable north-to-south progression with time, the presence of a toxin-free zone south of Cape Ann, Massachusetts, the sporadic nature of toxic outbreaks south of Massachusetts Bay, and the apparently rare occurrence of high toxicity levels well offshore on Nantucket Shoals and Georges Bank.     

Relevance of wound-activated compounds produced by diatoms as toxins and infochemicals for benthic invertebrates

Plants evolve the production of wound-activated compounds (WACs) to reduce grazing pressure. In addition, several plant-produced WACs are recognized by various invertebrates, playing the role of infochemicals. Due to co-evolutionary processes, some invertebrates recognize plant infochemicals and use them to identify possible prey, detect the presence of predators or identify algae containing various classes of toxic metabolites. Different metabolites present in the same algae can play the role of toxins, infochemicals or both simultaneously. We investigated the infochemical activity of compounds extracted from three diatoms epiphytes of the seagrass Posidonia oceanica, by conducting choice experiments on invertebrates living in the same community or in close proximity. Furthermore, the specific toxicity of the extracts obtained from the same algae was tested on sea urchin embryos using a standard bioassay procedure, to detect the presence of toxins. The comparison of the two effects demonstrated that invertebrates are subjected to diatom wound-activated toxicants when these algae are not associated with their own habitat, but they are able to recognize volatile infochemicals derived from diatoms associated with their habitats. The specific toxicity of WACs was shown to be inversely correlated to the perceptive ability of invertebrates towards volatile compounds liberated by the same algae. Hence, when the recognition of specific algae by a given invertebrate species evolves, their detrimental effects on the receiving organism may be lost.     

Individual and combined toxicity of some petroleum aromatics to the marine amphipod Elasmopus pectenicrus

Toxicity of 4 components of petroleum oils to the marine amphipod Elasmopus pectenicrus (Bate) has been assessed. Two ephemeral aromatic hydrocarbons, naphthalene (A) and 1, 2, 4-trimethylbenzene (B) were more toxic than two persistent aromatics, o-cresol (C) and o-toluidine (D). The acute toxicity concentrations obtained for individual aromatic compounds were always greater than the actual concentrations found in the water-soluble fractions (WSF) of fuel oils. Results from mixtures of 2 or more components indicated that the LC₅₀ levels were primarily determined by the more toxic substances, A and B. Naphthalene and 1, 2, 4-trimethylbenzene became more toxic to the E. pectenicrus when present in a mixture of more than 2 components, and the toxicity increased with increasing numbers of components present. Synergistic effects, therefore, possibly occur in the whole WSF. No antagonistic effects were observed among the 4 petroleum aromatics.University of Texas, Marine Science Institute Contribution No. 290     

利用厌氧颗粒污泥处理氯代有毒有机物

用能进行还原脱氯的微生物富集物接种，在小型试验装置内成功地培养出了具有还原脱氯功能的颗粒污泥。五氯苯酚能被这种颗粒污染完全脱氯并进一步分解为甲烷和二氧化碳。四氯乙烯和其他氯代乙烯能被颗粒污还原脱氯为乙烯。这种脱氯的颗粒污泥可用来处理含有五氯苯酚和氯乙烯类的废水和地下水。     

Industrial organic contaminants: identification,toxicity and fate in the environment

Industrialization and urbanization in the more economically developed countries and also in emerging and developing nations have led to an intensive and still increasing use of water resources. The involved chemical contamination led to a deterioration of aquatic systems in many areas. Industries are important pollution sources and the discharged wastewaters may contain very diverse and potentially harmful organic compound groups. We therefore present here a comprehensive review of the current state of knowledge of organic contaminants from industrial wastewaters. The available studies proved the heterogenic chemical composition of industrial wastewaters, even from the same industry branches, and the presence of heterogenic organic contaminant mixtures from industrial sources in aquatic systems. We conclude that our knowledge of the chemical composition of industrial wastewaters and the occurrence of industrial organic contaminants in the environment is as yet very limited. A combination of chemical and toxicological methods enabled the identification of toxic organic constituents in industrial wastewaters. Chemical evaluations of industrial contamination linked to surveys of environmental impacts could relate toxic effects of field samples to the presence of specific contaminants. Exposure experiments in the field proved the bioaccumulation and toxicity of several industrial compounds. Ecological surveys in industrial areas combined with a comprehensive chemical characterization and toxicity evaluation are so far missing. Some of the identified organic contaminants are related to characteristic industrial production processes, and their presence in water, sediment or biota indicates the input of specific industrial wastewaters. Accordingly, these compounds can be used as industrial markers. We suggest the proceeding application of the marker concept, as markers are useful to verify the input of specific industrial wastewaters to aquatic systems and to investigate the spatial distribution of the emission. Such information helps to disentangle different emission sources for the subsequent investigation of potential impacts in the environment.