离子液体与有机磷农药间的毒性相互作用

"绿色"溶剂离子液体(ILs)与其他污染物之间的毒性相互作用已有报道,但相关数据仍较为缺乏。以7种具有不同阴阳离子组成的ILs:溴化丁基吡啶(IL1)、氯化丁基-2,3-二甲基咪唑(IL2)、丁基-3-甲基咪唑翁磷酸盐(IL3)、丁基-3-甲基咪唑正辛基硫酸(IL4)、丁基-2,3-二甲基咪唑二乙二醇单甲醚硫酸盐(IL5)、辛基-3-甲基咪唑二乙基醚单甲磺硫酸(IL6)和氯化己基-3-甲基咪唑(IL7),与5种有机磷农药(OPs):敌敌畏(DIC)、乐果(DIM)、草甘膦(GLY)、久效磷(MON)和磷胺(PHO),作为混合物组分,以等效应浓度比射线法设计7种ILs分别与5种OPs等EC_(50)配比的35组二元混合物,应用微板毒性分析法(MTA)测定这些混合物对青海弧菌Q67的毒性,以浓度加和(CA)和独立作用(IA)为参考模型分析毒性相互作用。结果表明,不同的IL-OP混合物呈现的作用类型不同:如IL1-DIM、IL2-DIM、IL3-DIM、IL6-DIM、IL2-MON和IL7-DIM的混合物呈明显的拮抗作用;IL3-DIC和IL2-GLY的混合物呈明显的协同作用;IL5-DIM和IL4-MON的混合物在较高浓度区呈拮抗作用;而IL3-GLY和IL6-DIC的混合物在较高浓度区呈协同作用;其余的混合物则为加和作用。     

有机磷农药对蛋白核小球藻的毒性相互作用研究

水体中农药复合污染产生的毒性效应具有潜在风险。为系统考察有机磷农药(OPs)混合物对淡水生态系统中绿藻的联合毒性效应,以马拉硫磷(MIT)、敌敌畏(DDVP)、敌百虫(TRC)、乐果(DIT)和氧乐果(OMT)等5种OPs作为混合物组分,运用直接均分射线法设计9组二元混合物体系共45条混合物射线。利用96孔微板测定5种OPs及其二元混合物对蛋白核小球藻(C. pyrenoidosa)的生长抑制毒性,通过基于置信区间的组合指数法分析混合物的联合毒性及毒性相互作用。结果表明,以p EC50为毒性指标,5种OPs对C. pyrenoidosa的毒性大小顺序为:TRCMITDDVPOMTDIT,OPs对C. pyrenoidosa的毒性大小受其中心磷原子的电正性影响;因混合组分的不同,部分OPs混合物对C. pyrenoidosa的联合毒性依赖于组分浓度比; OPs混合物对C. pyrenoidosa的毒性相互作用以加和为主,部分发生拮抗作用,发生拮抗作用的混合体系具有低效应区域呈加和作用,高效应区域呈拮抗作用的规律;与MIT混合的体系均有发生拮抗作用,且依赖于MIT浓度,MIT浓度比例越高,拮抗作用越强,OPs混合物的毒性相互作用与组分浓度比相关; OPs混合物的毒性相互作用组分浓度比依赖性与其联合毒性的组分浓度比依赖性规律不相关。     

Understanding the role of nano-TiO2 on the toxicity of Pb on C. dubia through modeling–Is it additive or synergistic?

• A two-compartment model is able to quantify the effect of nano-TiO₂ on Pb toxicity. • Nano-TiO₂ reduces Pb tolerance level and increased the killing rate for C. dubia. • Thus, nano-TiO₂ synergistically enhances Pb toxicity. • Algae reduce Pb transfer rate to the body tissue and the killing rate. Nano-TiO₂ can remarkably increase lead (Pb) toxicity in aquatic organisms. However, the mechanism of this toxicity, additive or synergistic, is not well understood. To explore this mechanism, we inspected the role of nano-TiO₂ in the toxicity of Pb on Ceriodaphnia dubia (C. dubia), a model water flea species typically used for ecotoxicity studies. The effect of algae, a diet for aquatic organisms, on the effect of this binary mixture was also investigated. A two-compartment toxicokinetic (TK)-toxicodynamic (TD) modeling approach was used to quantify the Pb toxicity under these complex conditions and to develop critical parameters for understanding the mechanism of toxicity. This two-compartment modeling approach adequately described the Pb accumulation in the gut and in the rest of the body tissue under different nano-TiO₂ concentrations, with and without algae, and predicted the toxicity response of C. dubia. It indicated that increasing the nano-TiO₂ concentration reduced the Pb tolerance level and concurrently increased the killing rate constant of C. dubia. Therefore, nano-TiO₂ synergistically enhanced Pb toxicity. Algae remarkably reduced the toxicity of this binary mixture through reducing the Pb transfer rate to the body tissue and the killing rate, although it did not affect the Pb tolerance level. This two-compartment modeling approach is useful in understanding the role of nanoparticles when assessing the overall toxicity of nanoparticles and other toxic elements in the environment.     

Toxicity of the nerve agent tabun to Daphnia magna, a new experimental species in military toxicology

Daphnia magna, a freshwater microcrustacean, is currently tested as an alternative experimental species in research dealing with nerve agents poisonings treatment. Because of this, the toxicity of the nerve agent tabun (a cyanide-group containing organophosphate) to Daphnia had to be examined by estimating the EC₅₀ values. The immobilization of daphnids was chosen as the end-point. It was found that D. magna is sensitive to small amounts of tabun, even after 15 min exposure, and tabun toxicity increases with time. The estimated EC₅₀ values for 15, 30, 45, and 60 min exposure were as follows: 67.39, 38.10, 26.95, and 21.9 μg l^-1. In addition, the toxicity of media to which tabun was added 24 h before the start of experiments was examined. The results obtained indicate that daphnids can be used in experiments with nerve-agent intoxication treatment.     

十溴联苯醚(BDE-209)对土壤跳虫的急、慢性毒性效应

为揭示溴代阻燃剂对土壤生态系统的潜在危害,采用回避实验和繁殖实验评价了十溴联苯醚(BDE-209)对2种土壤跳虫Folsomia candida和Folsomia fimetaria的急/慢性毒性。48h的急性回避实验中,BDE-209对F.candida和F.fimetaria产生毒性效应的EC_(50)值分别为1.27和0.79mg·kg~(-1),LOEC值均小于0.5mg·kg~(-1)。慢性繁殖实验中,BDE-209对F.candida和F.fimetaria繁殖毒性的EC_(50)值分别为0.81和0.56mg·kg~(-1),LOEC值分别为<0.25和<0.5mg·kg~(-1)。研究表明,土壤BDE-209污染对跳虫的繁殖和环境行为有显著影响,且在较低暴露浓度下(0.25mg·kg~(-1))即对跳虫繁殖产生抑制效应;有性生殖的F.fimetaria比孤雌生殖的F.candida对BDE-209污染的毒性响应更为敏感。     

Additive und synergistische Kombinationswirkungen von Xenobiotika in subtoxischen Konzentrationen auf menschliche Fibroblasten

The toxic combination effects of xenobiotics of different substance classes were investigated in human fibroblasts. Subtoxic concentrations of 4-chloroaniline enhanced the toxicity of 2,4-dichlorophenoxyacetic acid (2,4-D, dimethylammonium salt) in an additive manner. A mixture of 4-chloroaniline, dicofol and 4-chlorophenol increased the toxicity of 2,4-D synergistically. The concentrations of the components used in the mixture were one third of their ?no observed effect concentrations” (NOEC). The combination of 4-chloroaniline, dicofol and 4-chlorophenol (without 2,4-D) at subtoxic concentrations also showed synergistic effects. The great differences in the lipophilicity of the combined substances might be the cause of the synergistic action.     

Combined process of biofiltration and ozone oxidation as an advanced treatment process for wastewater reuse

The effluent of a wastewater treatment plant was treated in a pilot plant for reclaimed water production through the denitrification biofilter (DNBF) process, ozonation (O₃), and biologic aerated filtration (BAF). The combined process demonstrated good removal performance of conventional pollutants, including concentrations of chemical oxygen demand (27.8 mg·L⁻¹) and total nitrogen (9.9 mg·L⁻¹) in the final effluent, which met the local discharge standards and water reuse purposes. Micropollutants (e.g., antibiotics and endocrine-disrupting chemicals) were also significantly removed during the proposed process. Ozonation exhibited high antibiotic removal efficiencies, especially for tetracycline (94%). However, micropollutant removal efficiency was negatively affected by the nitrite produced by DNBF. Acute toxicity variations of the combined process were estimated by utilizing luminescent bacteria. Inhibition rate increased from 9% to 15% during ozonation. Carbonyl compound concentrations (e.g., aldehydes and ketones) also increased by 58% as by-products, which consequently increased toxicity. However, toxicity eventually became as low as that of the influent because the by-products were effectively removed by BAF. The combined DNBF/O₃/BAF process is suitable for the advanced treatment of reclaimed water because it can thoroughly remove pollutants and toxicity.     

五氯酚钠对鲫鱼的急性毒性：悬浮颗粒物的影响

悬浮颗粒物在水生态系统中普遍存在,为了研究悬浮颗粒物对氯酚类化合物生物毒性的影响,以高岭土为模拟悬浮颗粒物,考察了不同浓度的悬浮颗粒物(0、25、50、100、250和500mg·L~(-1))存在条件下五氯酚钠(NaPCP)对鲫鱼(Carassius auratus)的毒性效应。等温吸附实验结果显示,悬浮颗粒物对水体中五氯酚钠的吸附作用不明显(P>0.05)。96h急性毒性实验结果显示,五氯酚钠对鲫鱼的96h-LC_(50)随颗粒物浓度([SS])的增加而减小,两者间的关系为LC_(50)=146.7exp(-[SS]/186.8)+121.7,r~2=0.99。等效线图法评价结果表明,悬浮颗粒物可增强五氯酚钠对鲫鱼的急性毒性,两者呈毒性增加作用。     

A multi-integrated approach on toxicity effects of engineered TiO2 nanoparticles

The new properties of engineered nanoparticles drive the need for new knowledge on the safety, fate, behavior and biologic effects of these particles on organisms and ecosystems. Titanium dioxide nanoparticles have been used extensively for a wide range of applications, e.g, self-cleaning surface coatings, solar cells, water treatment agents, topical sunscreens. Within this scenario increased environmental exposure can be expected but data on the ecotoxicological evaluation of nanoparticles are still scarce. The main purpose of this work was the evaluation of effects of TiO₂ nanoparticles in several organisms, covering different trophic levels, using a battery of aquatic assays. Using fish as a vertebrate model organism tissue histological and ultrastructural observations and the stress enzyme activity were also studied. TiO₂ nanoparticles (Aeroxide® P25), two phase composition of anatase (65%) and rutile (35%) with an average particle size value of 27.6±11 nm were used. Results on the EC₅₀ for the tested aquatic organisms showed toxicity for the bacteria, the algae and the crustacean, being the algae the most sensitive tested organism. The aquatic plant Lemna minor showed no effect on growth. The fish Carassius auratus showed no effect on a 21 day survival test, though at a biochemical level the cytosolic Glutathione-S-Transferase total activity, in intestines, showed a general significant decrease (p<0.05) after 14 days of exposure for all tested concentrations. The presence of TiO₂ nanoparticles aggregates were observed in the intestine lumen but their internalization by intestine cells could not be confirmed.     

Allelopathic inhibition on red tide microalgae by five macroalgal extracts

This study aims to identify effective antialgal allelochemicals from marine macroalgae that inhibit the growth of red tide microalgae. Practically, new algicidal agents were developed to control red tide. The growth inhibitory effects of 5 marine macroalgae Porphyra tenera, Laminaria japonica, Ulva pertusa, Enteromorpha clathrata, and Undaria pinnatifida on Skeletonema costatum were evaluated by adding crude seawater extracts of macroalgal dry tissue into the culture medium containing S. costatum. The half-effective concentrations at 120 h (EC_{50, 120 h}) of the seawater extracts were 0.6, 0.9, 1.0, 1.0, and 4.7 g/L for the five macroalgae above, respectively. E. clathrata, L. japonica and U. pertusa showed strong allelopathic effect on the growth of S. costatum. There have been no previous reports with regard to the allelopathic effects of the former two macroalgae so far. The possible allelochemicals of 21 compounds of the E. clathrata were detected using Gas chromatography-mass spectrometry (GC-MS) analysis. Unsaturated fatty acids, acrylic acid (C₃H₄O₂), and linolenic acid (C₁₈H₃₀O₂) were the most likely allelochemicals in E. clathrata.     

Biomarkers indicate mixture toxicities of fluorene and phenanthrene with endosulfan toward earthworm (<Emphasis Type="Italic">Eisenia fetida</Emphasis>)

α-Endosulfan and some polycyclic aromatic compounds (PAHs) are persistent in the environment and can reach crop products via contaminated agricultural soils. They may even be present as mixtures in the soil and induce mixture toxicity in soil organisms such as earthworms. In this study, the combined toxicities of PAHs with α-endosulfan were determined in Eisenia fetida adults using an artificial soil system. α-Endosulfan and five PAHs were tested for their acute toxicity toward E. fetida in artificial soils. Only α-endosulfan, fluorene, and phenanthrene showed acute toxicities, with LC₅₀ values of 9.7, 133.2, and 86.2 mg kg^?1, respectively. A mixture toxicity assay was conducted using α-endosulfan at LC₁₀ and fluorene or phenanthrene at LC₅₀ in the artificial soils. Upon exposure to the mixture of fluorene and α-endosulfan, earthworms were killed in increasing numbers owing to their synergistic effects, while no other mixture showed any additional toxicity toward the earthworms. Along with the acute toxicity results, the biochemical and molecular changes in the fluorene- and phenanthrene-treated earthworms with or without α-endosulfan treatment demonstrated that enhancement of glutathione S-transferase activity was dependent on the addition of PAH chemicals, and the HSP70 gene expression increased with the addition of α-endosulfan. Taken together, these findings contribute toward understanding the adverse effects of pollutants when present separately or in combination with other types of chemicals.     

己烯雌酚与四溴双酚A对小球藻生长效应的影响（Effects of Diethylstilbestrol and Tetrabromobisphenol A on Growth of Chlorella pyrenoidosa）

采用化学品对藻类毒性测试的标准试验方法,分别研究了己烯雌酚和四溴双酚A单组分对小球藻生长及光合色素含量的影响,并用相加指数法评价了己烯雌酚和四溴双酚A双组分对小球藻的联合毒性效应.结果表明,藻细胞密度和光合色素含量随己烯雌酚和四溴双酚A浓度增加而明显下降,且均表现出较好的浓度-效应关系,其对小球藻的96h-EC50值分别为0.0248mg·L-1和0.0455mg·L-1;两者对小球藻96h的联合毒性效应为拮抗作用.     

Long-term exposure to air pollution and cerebrovascular disease: findings from Beijing Health Management Cohort study

● This study explored the long-term association by double robust additive models. ● Individual exposure concentrations were assessed by integrating GAM, LUR and BPNN. ● PM_2.5, SO₂ and NO₂ are positively associated with cerebrovascular disease. ● CO could reduce the risk of cerebrovascular disease with the highest robustness. ● The elderly, women and people with normal BMI are at higher risk for air pollution. The relationship between air pollution and cerebrovascular disease has become a popular topic, yet research findings are highly heterogeneous. This study aims to investigate this association based on detailed individual health data and a precise evaluation of their exposure levels. The integrated models of generalized additive model, land use regression model and back propagation neural network were used to evaluate the exposure concentrations. And doubly robust additive model was conducted to explore the association between cerebrovascular disease and air pollution after adjusted for demographic characteristics, physical examination, disease information, geographic and socioeconomic status. A total of 25097 subjects were included in the Beijing Health Management Cohort from 2013 to 2018. With a 1 μg/m³ increase in the concentrations of PM_2.5, SO₂ and NO₂, the incidence risk of cerebrovascular disease increased by 1.02 (95% CI: 1.008–1.034), 1.06 (95% CI: 1.034–1.095) and 1.02 (95% CI: 1.010–1.029) respectively. Whereas CO exposure could decrease the risk, with an odds ratio of 0.38 (95% CI: 0.212–0.626). In the subgroup analysis, individuals under the age of 50 with normal BMI were at higher risk caused by PM_2.5, and SO₂ was considered more hazardous to women. Meanwhile, the protective effect of CO on women and those with normal BMI was stronger. Successful reduction of long-term exposure to PM_2.5, SO₂ and NO₂ would lead to substantial benefits for decrease the risk of cerebrovascular disease especially for the health of the susceptible individuals.     

An isobole-based statistical model and test for synergism/antagonism in binary mixture toxicity experiments

Synergism and antagonism are often defined in relation to the model of Concentration Addition (CA). Hence, it is vital for the conclusion of mixture toxicity studies to be able to test whether an observed deviation from CA reflects a true deviation or whether it is simply due to random variation. In this paper we consider a non-linear regression model for the classical ray designs for binary mixture experiments. The model combines dose–response curves for each mixture in the experiment with an isobole model, describing possible deviations from CA. The method allows us to test whether the chosen isobole model is reasonable for the data and to test the hypothesis of CA. Furthermore, it provides us with a measure of the degree of synergism/antagonism. The method is flexible since both the dose–response relationships and the isobole model can be chosen arbitrarily. We demonstrate the use of the method on datasets where combinations of pesticides are tested on a floating plant, Lemna minor, and an algae, Pseudokirchneriella subcapitata. Furthermore, we conduct a simulation study in order to explore the power with which a specific deviation from CA can be distinguished in different test-systems.     

Assessing combined toxic effects of tetracycline and P25 titanium dioxide nanoparticles using Allium cepa bioassay

• UVA pre-irradiation to TiO₂ NPs enhanced its toxicity toward plant A. cepa. • UVA TiO₂ NPs increased intracellular ROS, resulting in more cell damage. • Cell death enhanced cell permeability and increased uptake of NPs. • Being highly toxic (EC₅₀ = 0.097 µmol/L), TC did not increase ROS generation. • Even at a low dose, TC enhanced the toxic potential of TiO₂ NPs significantly. Usage of titanium dioxide nanoparticles (TiO₂ NPs) and tetracycline (TC) has increased significantly in the present era. This leads to their release and accumulation in the environment. Both the compounds, individually, can have adverse toxic effects on the plants. Their binary mixtures can increase this degree of damage. The present study aimed to evaluate the toxicity of both the contaminants in individual and binary mixtures in Allium cepa. Further, the toxicity of TiO₂ NPs upon UVA pre-irradiation was also measured. Results showed that UVA pre-irradiated NPs (UVA-TiO₂ NPs) had a significant decrease in cell viability than their non-irradiated counterparts (NI-TiO₂), denoting an increase in photocatalytic activity upon UVA pre-irradiation. Very low concentrations of TC (EC₁₀ = 0.016 µmol/L) mixed with TiO₂ NPs significantly increased the toxicity for both UVA-TiO₂ and NI-TiO₂ NPs. Intracellular ROS generation was significantly high for UVA-TiO₂ NPs. However, TC did not have any effects on ROS production. Both the compounds exhibited genotoxic potential in A. cepa. Different chromosomal abnormalities like anaphase bridges, telophase bridges, laggard chromosomes, binucleate cells, etc. were observed. The binary mixture of UVA-TiO₂ NPs and TC showed the highest chromosomal aberrations (64.0%±1.26%) than the mixture with NI-TiO₂ or the individual contaminants. This decreased significantly after recovery (46.8%±1.92%), denoting the self-repair processes. This study proved that UVA-TiO₂ NPs were more toxic and could be enhanced further when mixed with a sub-lethal concentration of TC. This work will help to assess the risk of both compounds in the environment.     

Washing out heavy metals from contaminated soils from an iron and steel smelting site

Washing is a promising method for separating contaminants bound to the particles of soil ex-situ by chemical mobilization. Laboratory batch washing experiments were conducted using deionized water and varying concentrations of oxalic acid, citric acid, tartaric acid, acetic acid, hydrochloric acid and ethylenediaminetetra acetic acid (EDTA) to assess the efficiency of using these chemicals as washing agents and to clean up heavy metals from two heavily polluted soils from an iron and streel smelting site. The toxicity reduction index and remediation costs were analyzed, and the results showed that the soils were polluted with Cd, Pb and Zn. Hydrochloric acid and EDTA were more efficient than the other washing agents in the remediation of the test soils. The maximum total toxicity reduction index showed that 0.5 mol·L^-1 hydrochloric acid could achieve the remediation with the lowest costs.     

3种新型污染物对发光菌的毒性作用研究

分析了3种常见的代表性新型污染物对发光菌的单一毒性和等毒性比例下的联合毒性,基于毒性单位法(TU)、相加指数法(AI)和混合毒性指数法(MTI)评价混合体系联合毒性作用类型。三氯生、五氯酚、双酚A对发光菌的半数效应浓度(EC_(50))分别为:0.045、0.035、0.74 mg·L~(-1)。不同的评价方法对3种新型污染物的联合效应评价结果具有较好的一致性,多元混合体系呈现为不同程度的拮抗作用,结合分子结构特征和不同取代基的相互作用,初步分析了联合毒性机理,进一步毒性作用机制还需要通过对生物生理生化响应等进行深入研究。新型污染物混合体系对发光菌的联合作用呈现以拮抗作用为主,表明此类污染物环境残留可导致相关化学品功效降低,引发微生物耐药性的产生和传播的风险。     

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.     

Inhibition character of crotonaldehyde manufacture wastewater on biological acidification

• The inhibition of the main organic pollutions in CMW was demonstrated. • Variations of AK and BK showed a high correlation with the SAA of Ac and n-Bu. • The inhibitory degree was in the order of Ac>n-Bu for individual toxicants. • Biodegradation products of the main toxicants were analyzed. This work aims to investigate the inhibitory effect of crotonaldehyde manufacture wastewater (CMW) on biological acidification. To reveal the inhibitory effect of wastewater to the anaerobic granular sludge (AnGS), variations of the specific acidogenic activity (SAA) and activities of key enzymes were investigated. The results indicated that the dosage of CMW causing a 50% effect concentration (EC₅₀) on the activity of total volatile fatty acids (TVFA) production was 380 mg COD/g VSS. The inhibitory effect of individual toxicants in CMW on the activity of TVFA production were in the order of crotonaldehyde>ethyl sorbate>(E,E)-2,4-hexadienal, and their inhibitory degrees on individual VFA products were acetic acid (Ac)>n-butyric acid (n-Bu), which could correspond to the variations in the activities of acetate kinase (AK) and butyrate kinase (BK). Furthermore, the combined effect of three toxicants on the activity of TVFA production was significantly higher than that of any individual toxicant, and the contribution of the relative toxicity to CMW was 77.27%. Additionally, the biodegradation products of the main toxicants indicated that the removal of crotonaldehyde and (E,E)-2,4-hexadienal was primarily due to the hydrogenation of alkene and aldehyde and the oxidation of aldehyde. Nevertheless, the removal of ethyl sorbate was primarily based on adsorption. In conclusion, biological acidification has a limited ability to treatment CMW, therefore, a further pretreatment technology should be used to remove the main toxicant of wastewater.