Acute toxicity of industrial endocrine-disrupting chemicals,natural and synthetic sex hormones to the freshwater planarian,Dugesia japonica

Many chemicals commonly occurring in surface water are found to be hormonally active. Fourteen compounds including four sex hormones, three synthetic hormones, one non-steroidal anti-androgen, and six industrial endocrine-disrupting chemicals were selected to examine their acute toxicities on the freshwater planarian, Dugesia japonica. Among all test chemicals, diethylstilbestrol had the highest toxicity. Relatively, the toxicities of the synthetic hormones were higher than the natural ones. Among the six industrial endocrine-disrupting chemicals tested, bisphenol A was the most toxic, with a 48-h LC₅₀ of 8.3 mg L^?1. Overall, the natural or synthetic hormones, other than estrone and estriol, were more acutely toxic to planarians than the industrial endocrine disruptors tested. The acute toxicities of the test chemicals to Dugesia japonica were in the same order of magnitude as those to Daphnia magna based on available published data. Despite this study used non-environmentally relevant levels, such kinds of chemicals do not exist singly in the aquatic environment, but typically act in synergistic and/or additive ways in the complex environmental mixtures, and the total estrogen equivalents are much higher than a single chemical. This study stands as a starting point for other acute and chronic assays, namely using mixtures.     

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.     

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。     

Chemical composition of dietary species of marine unicellular algae and rotifers with emphasis on fatty acids

The lipid profiles of a few species of marine unicellular algae and yeast were studied with emphasis on fatty acids as part of a search for the nutritional value of plankton to the diet of marine fish larvae commonly used in marine hatcheries. The general proximate chemistry of rotifers was closely related to the proximate chemistry of the diet organism, exhibiting a higher content of protein and carbohydrate and a lower content of lipid. Major lipids in all algae, yeast and rotifers comprised mono-, di- and tri-glycerides and polar lipids. The algae Chaetoceros gracilis Schutt, Isochrysis galbana Parke and their respective algaefed rotifers exhibited higher amounts of neutral lipids, consisting mainly of cyclic and branched polyunsaturated components. Fatty acid composition of the algae was species-specific, with the highest ratio of polyethylenic to saturated and monoethylenic acid in I. galbana and Phaeodactylum tricornutum Bohlin, and the highest content (15%) of n-3 highly unsaturated fatty acids in Nannochloropsis salina and P. tricornutum. A closely mirrored distribution of the fatty acids, but with a lower amount of n-3 highly unsaturated fatty acids, was present in the respective algae-fed rotifers. Comparison of the fatty acid spectrum of Artemia sp. and Euterpina acutifrons grown in the laboratory on I. galbana with zooplankton samples of E. acutifrons and Oitona nana collected from the sea showed a higher concentration of docosahexaenoic acid (22:6 n-3) in the naturally collected sample. The results indicate that the efficacy of the food algae C. gracilis and I. galbana in increasing the survival of fish larvae in marine hatcheries is not obvious on the sole basis of fatty acid composition.     

Nitrate toxicity toPenaeus monodon protozoea

Increased levels of nitrate occur in natural waters due to pollution, and in aquaculture systems from nitrification and addition of microalgal cultures for feeding. Static bioassays showed that significant mortality of larvalPenaeus monodon (Fabricius) occurred within 40 h at nitrate concentrations as low as 1 mg NO ₃ ^- l^–1. Sublethal effects of this concentration resulted in changes to ganglionic neuropiles and muscles. At higher concentrations (10 and 100 mg NO ₃ ^- l^–1), additional tissues were affected including the hypodermis, midgut and proventriculus. This is the first report of toxicity to a marine organism of nitrate at concentrations normally present in enclosed seawater and mariculture systems. The results are discussed in terms of management of culture systems and of natural marine ecosystems containing elevated levels of nitrate.     

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.     

The influence of suspension density and temperature on the filtration rate of Hiatella arctica

The rate of filtering Phaeodactylum tricornutum and Isochrysis galbana was measured in Hiatella arctica (L.) by the indirect suspension depletion method monitored by optical density measurement. The filtration rate of H. arctica was found to be 1.412×10^–2 l/h/g wet weight at a temperature of 15°C when fed with P. tricornutum, at average cell concentrations up to 3.5×10⁶ cells/ml. The filtration rate dropped almost to zero when the concentration of P. tricornutum reached 11×10⁶ cells/ml. The filtration rate of I. galbana diminished at a much lower cell concentration of 1×10⁶ cells/ml, and almost ceased at 3 to 4×10⁶ cells/ml. In mixed cultures of I. galbana and P. tricornutum, the filtration rate ratio was 0.37 to 1.00, and this was believed to be due to a proportion of the smaller former cells passing through the ostia. However, when resuspended in sea water, I. galbana cells were taken at a rate slightly less than P. tricornutum. The medium in which the I. galbana cells had been grown was inhibitory to the filtering activity of H. arctica, since, when cells of either alga were resuspended in the medium, the filtration rate was considerably reduced. No inhibitory factor existed in either of the original nutrient media. Hence, the importance of using low cell concentrations and of eliminating any inhibitory metabolic products when measuring filtration rates of bivalves is stressed. H. arctica shows a typical activity temperature eurve for a boreo-arctic species, with a steady rise from 0°C to a maximum between 15° and 17°C, and a sharp fall in activity to about zero at 25°C. The rates of filtration of various species at temperatures approaching the optimum were compared after allowance was made for fall in filtration rate with increasing body weight. The results suggested that the Mytilacea had the highest filtration rates and that H. arctica possesses one of the lowest filtration rates recorded.     

6种苯系物对球等鞭金藻和新月菱形藻的生长抑制

海洋环境中苯系物污染主要来源于海洋溢油事故以及沿海石油化工企业的废水排放。为探究苯系物对海洋微藻的毒性作用,选择球等鞭金藻和新月菱形藻作为受试生物,分别考察了苯、甲苯、乙基苯、邻-二甲苯、间-二甲苯和对-二甲苯6种苯系物对2种海洋微藻生长的影响。结果表明,在0.25~64.0 mg·L-1暴露浓度下,6种苯系物对2种微藻生长具有显著的抑制作用,随着暴露浓度的升高,抑制作用明显增强。苯、甲苯、乙基苯、邻-二甲苯、间-二甲苯、对-二甲苯对球等鞭金藻的24 h的半数效应浓度(24 h-EC50)分别为:17.07、12.88、7.58、0.55、0.36、0.27 mg·L-1;对新月菱形藻的24 h-EC50值分别为:1.03、0.68、0.46、0.40、0.42、0.38 mg·L-1。上述研究结果为确定苯系物海洋环境质量标准、保护海洋生态环境提供了基础数据。     

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     

基于形态修正的描述符构建可电离化合物对大型溞急性毒性的QSAR模型

在环境水体中,可电离有机化合物(IOCs)可解离为分子和离子形态。研究表明,IOCs离子形态的环境行为、毒性效应等都与其分子形态存在较大差异,因而在研究IOCs环境行为、毒性效应时不应忽略离子化的影响。在构建IOCs相关预测模型时如何表征离子化的影响是当前研究的重要内容之一。探讨了采用基于形态修正的描述符构建IOCs水生毒性预测模型的可行性。具体而言,采用逐步多元线性回归(MLR)方法,构建了可预测63种取代酚、取代苯甲酸和取代苯胺等IOCs对大型溞急性毒性的定量结构-活性关系(QSAR)模型。与仅采用分子形态描述符的模型相比,使用基于形态修正描述符的模型决定系数(R2)、去一法交叉验证系数(Q2LOO)、外部验证系数(Q2EXT)等参数从0.622～0.705提高到了0.840～0.875,表明基于形态修正描述符的模型具有更好的拟合优度、稳健性和预测能力。因此,在将来的研究中,可采用基于形态修正的描述符构建IOCs水生毒性效应预测模型。     

Responses of three mouse species to deterrent chemicals in the monarch butterfly. I. Taste and toxicity tests using artificial diets laced with digitoxin or monocrotaline

Summary Of three common mouse species at the Mexican overwintering sites of the monarch butterfly, onlyPeromyscus melanotis eats monarchs. We hypothesized thatP. aztecus andReithrodontomys sumichrasti reject monarchs because they are more sensitive to the bitter taste and/or toxic effects of the cardiac glycosides (CGs) and pyrrolizidine alkaloids (PAs) in the butterflies. Two-choice preference tests revealed no difference in taste avoidance thresholds to free base and N-oxide forms of the PA, monocrotaline, but very different avoidance thresholds to the CG, digitoxin. Avoidance thresholds forR. sumichrasti andP. aztecus were, in respective order, 1020 and 34 times less than that forP. melanotis. We also tested the toxic sensitivity of juvenile mice by chronically feeding diets containing digitoxin or monocrotaline at concentrations similar to those used in the preference tests. No species developed CG toxicity, but bothP. melanotis andP. aztecus developed moderate PA toxicity (R. sumichrasti was not tested for PA toxicity).P. aztecus grew more slowly and manyP. melanotis had hepatic metabolic lesions. Thus, the three mouse species responded very differently to the taste and toxic properties of CGs and PAs at ecologically relevant concentrations: 1) CGs were taste rejected by all species exceptP. melanotis, while PAs were not; and 2) PAs were toxic, while CGs were not.     

Effects of 9–10 dihydroanthracene and its biodegradation products on the marine diatom Phaeodactylum tricornutum

Growth, photosynthetic capacity and chlorophyll a content of the marine diatom Phaeodactylum tricornutum Bohlin were observed after exposure to the aromatic hydrocarbon 9–10 dihydroanthracene and its biodegradation products. Growth was inhibited after exposure to the aromatic hydrocarbon, whereas no inhibition occurred in the presence of the biodegradation products alone. The degradation products were found to enhance the chlorophyll a cellular content. Synergistic effects between dihydroanthracene and its biodegradation products increased the toxicity of this aromatic hydrocarbon.     

Monitoring toxicity of an azo dye methyl red and a heavy metal Cu,using plant and animal bioassays

Toxicities of an azo dye methyl red and a heavy metal copper (Cu) were quantified, using growth and mortality as end points, in four plant species and three animal species by subjecting them to short-term (4 days for animals, 10 days for plants) static bioassays. Lemna aequinoctialis Welwitch (EC₅₀: 7–16 ppm) was found to be the most sensitive species for methyl red, Ceratophyllum demersum L. (EC₅₀: 25 ppm) and Lactuca sativa L. (EC₅₀: 56 ppm) were intermediate, while Oryza sativa L. shows reduction in seedling vigor (9–27%) of <50%, being the least sensitive amongst the tested plant species. Methyl red toxicity is almost 3–5-fold higher in growing medium (pH = 5.8–6.0), even at high nutrient levels, while Cu toxicity is higher in nutrient-poor alkaline medium at alkaline pH (8.3–8.7; EC₅₀: Ceratophyllum = 104–200 ppb; Lemna = 100–170 ppb) compared to nutrient-rich acidic medium (pH = 5.4–5.7; EC₅₀: Ceratophyllum = 2600–3175 ppb; Lemna = 4350–4715 ppb). Rice tolerance (EC₅₀: 6500 ppb) was found to be higher than hydrophytes while lettuce was most tolerant to Cu. Fish sensitivity toward the test chemicals was almost parallel to Ceratophyllum and Lemna [Gambusia affinis Baird and Gerard (LC₅₀: 250 ppb for Cu) and Poecilia reticulata Peters (LC₅₀: 24 ppm for methyl red)]. Similar to the plants, dye toxicity increased markedly (LC₅₀: 7 ppm) in the acidic medium (pH = 6.0). Amongst the tested organisms, Daphnia was found to be most sensitive to methyl red (EC₅₀: 6 ppm) while its sensitivity to Cu (EC₅₀: 230 ppb) was similar to hydrophytes and fish. Initially, the combination of dye and Cu (at their sublethal concentrations) had additive effects in duckweed, while dye concentration ruled afterward. These results indicate that hydrophytes and animals are equally sensitive toward the test chemicals. Dye toxicity in hydrophytes and fish was pH dependent, while in the case of Cu, it is related to the nutrient status of the growth medium of plants.     

Particle retention and selection by larvae and spat of Ostrea edulis in algal suspensions

Grazing rates and electivity indices of larvae and spat of Ostrea edulis L. were, measured and examined in relation to certain physical parameters using a flow-through system. Retention and size-selection were determined for the major particle sizes present in cultures of Isochrysis galbana Parke, an alga used frequently as food for bivalves. Cultures of the algae Dunaliella tertiolecta Butcher and Phaeodactylum tricornutum Bohlin were used as sources of particle suspensions of various sizes and shapes, respectively. While increases in flow rate caused increased grazing, the mode of selection of I. galbana particles remained constant. Filtration rate, F _f was related to body size, W, by the general allometric equation R _f =aW ^b,while particle-size preference in suspensions of I. galbana by both larvae and spat of O. edulis was independent of W. Grazing rates increased with temperature to an optimum temperature, which was related to the acclimation temperature. Increases above this optimum caused a reduction in feeding activity. No significant change in particle size-preference in the I. galbana suspension with temperature was observed. Grazing rates and selection were dependent, however, on particle number and volume. Both larvae and spat displayed maximum retention at optimum particle concentrations which tended to decrease with increasing particle size. Variations in cell shape of P. tricornutum had no measurable effect on selectivity by O. edulis.     

Toxicity of copper to the marine amphipod Allorchestes compressa in the presence of water-and lipid-soluble ligands

Acute toxicity tests were carried out on the marine amphipod Allorchestes compressa Dana using copper sulphate and some organocopper complexes. For copper sulphate, 96 h LC₅₀ values of 0.11 and 0.5 mg Cu l^-1 were determined for the juveniles and the adults, respectively, juveniles being 4.5 times more sensitive to copper than adults. Organocopper complexes were tested on adults only. The three water-soluble ligands nitrilotriacetic acid, 8-hydroxyquinoline-5-sulphonic acid and tannic acid ameliorated copper toxicity by decreasing the concentration of free ionic copper, while lipid-soluble ligands such as oxine and potassium ethylxanthogenate increased copper toxicity, presumably as a result of the complexes diffusing through the cell membrane and participating in injurious reaction. The copper complex with 2,9-dimethyll, 10-phenanthroline was the most toxic complex tested. It is suggested that the presence of these ligands in the receiving water should be taken into consideration when establishing water-quality criteria.     

Temperature effects on the toxicity of four trace metals to adult spotted Babylonia snails (Babylonia areolata)

A study was conducted to determine the median lethal toxicity of four heavy metals on the marine gastropod Babylonia areolata. Median lethal toxicity tests were conducted to observe the sensitivity of this gastropod to metals and how variations in temperature might affect toxicity of test elements. Four heavy metals were used in the study. It was observed that the 96-hr LC₅₀ (in mg/L) for the different metals was found to be nickel (Ni) 33.53 (35.22–28.43), copper (Cu) 44.59 (46.43–41.53), cadmium (Cd) 21.53 (23.43–18.37), and zinc (Zn) 27.34 (28.81–24.24) at room temperature 24 °C. With temperature as a variable, median lethal concentration (LC₅₀) values were observed to increase from 22.41 mg/L at 10 °C to 27.34 mg/L at 28 °C and reduce to 18.43 mg/L at 30 °C and a further rise in toxicity was observed at 35 °C where LC₅₀ value was 12.7 mg/L as seen in the case of Zn. It was also observed that at 40 °C thermal and chemical toxicity overlapped as 100% mortality was observed in controls. This trend was noted in all metals for Babylonia areolata indicating that temperature played an important role in determining LC₅₀ values of toxicants.     

全氟辛烷磺酸盐(PFOS)替代品对中华蜜蜂的毒性

选用中国蜂种中华蜜蜂工蜂作为受试生物,建立其环境危害评价毒性测试方法,用所建立的方法对全氟辛烷磺酸盐(PFOS)替代品进行了接触急性毒性及经口急性毒性风险评价,并比较了"小烧杯法"和"饲喂管法"两种经口毒性方法的优缺点及对毒性结果的影响。研究结果表明,"小烧杯法"实验中C4织物三防整理剂对中华蜜蜂的24h-LC50为1435mg·L~(-1),48h-LC_(50)为284.67mg·L~(-1);其余替代品在限度实验均未出现蜜蜂死亡,4种PFOS替代品对中华蜜蜂的接触毒性及经口毒性均为低毒,但"小烧杯法"测得的经口毒性结果比"饲喂管法"高。     

不同微藻对典型行业废水急性毒性响应的敏感性研究

研究考察了不同行业废水对4种微藻24 h和72 h的急性毒性效应。以斜生栅藻(Scenedesmus obliquus)、蛋白核小球藻(Chlorella pyrenoidosa)、海水小球藻(Chlorella spp.)以及等鞭金藻(Isochrysis galbana)为指示生物,采用COD浓度较高的焦化厂实际生产废水和制药厂实际生产废水、COD浓度较低的印染厂生化处理后出水和城市污水处理厂进出水作为受试水体,以微藻的生长抑制率为测试指标,评价微藻对不同行业废水的急性毒性效应和敏感性。结果表明,不同行业废水对4种微藻的急性毒性效应有所不同:焦化废水对等鞭金藻的生长抑制作用最强,制药废水对斜生栅藻的毒性效应最为明显,印染废水及城市污水处理厂的进出水对海水小球藻的毒性较为显著,说明不同微藻对不同行业废水毒性的敏感性存在差异。上述研究结果为废水毒性评价中受试物种的选择提供了基础数据。     

3种农药及其复配剂对意大利工蜂的急性经口毒性

采用"小烧杯法"测定了3种农药及其复配剂对意大利工蜂的24 h、48 h急性经口毒性,根据我国《化学农药环境安全评价实验准则》中蜜蜂急性经口毒性划分等级可知,对意大利工蜂,35%精甲霜灵悬浮种衣剂属"低毒"级,25%噻虫嗪水分散粒剂属"高毒"级,25 g·L~(-1)咯菌腈悬浮种衣剂属"低毒",25%噻虫嗪-咯菌腈-精甲霜灵悬浮种衣剂也属"高毒"级。     

双酚A与其替代品对黑斑蛙急性毒性的比较

双酚F(BPF)和双酚S(BPS)作为双酚A(BPA)替代品广泛使用,然而有关BPF和BPS的毒性数据非常有限。采用系列浓度的BPA、BPF、BPS溶液,暴露黑斑蛙胚胎和蝌蚪96 h,通过半致死浓度(LC50)、最小生长抑制浓度(MCIG)和致畸率等指标比较3种化合物的急性毒性。结果显示:100 mg·L-1BPS未导致黑斑蛙胚胎及蝌蚪畸形和死亡。BPA和BPF对黑斑蛙胚胎的96h-LC50分别为7.68 mg·L-1和7.99 mg·L-1,MCIG分别为4.47 mg·L-1和4.77 mg·L-1,最大致畸率为33.33%;对蝌蚪的96 h-LC50分别为9.00 mg·L-1和9.52 mg·L-1。依据《化学农药环境安全评价准则》的毒性分级标准,判定BPA和BPF的毒性等级为中毒,BPS的毒性等级为低毒。表明BPF急性毒性与BPA相当,BPS急性毒性低于BPA。本研究数据可为BPF、BPS作为BPA替代品的生产和使用以及相应的环境管理提供毒理学参考。