淮河水体取代苯类污染及其生态风险

测定了13种取代苯类污染物、阿特拉津和乙草胺在淮河4个监测断面水、水体沉积物，鲤鱼（Grass Carp）中的浓度，并计算了上述有机污染物的生物富集因子（BAF）和生物沉积物浓缩因子（BSAF）。同时通过在现场放置的三油酸酯半渗透膜采样器（SPMD）研究，发现上述污染物在SPMD中的浓度和在鲤鱼脂肪或沉积物有机质中的浓度之间有显著相关性，因此，提出利用SPMD得到的三油酸酯沉积物富集因子（TSAF）来代替BSAF，用于沉积物污染生态风险评价。在怕检测的污染物中，影响水体水质的主要是2，4－二硝基苯，六氯苯，阿特拉津，采样断面中蚌埠的生态风险最大。     

三唑酮对青鳉鱼和大型溞不同测试终点的毒性效应评价

以青鳉鱼和大型溞为代表性水生生物,研究三唑酮对其不同测试终点的慢性毒性效应.结果显示,以生存、生长、繁殖为测试终点,青鳉鱼的NOEC分别为76,60,5μg/L,基于大型溞蜕皮次数、生长和繁殖的NOEC分别为25,100,200μg/L.由此可见,青鳉鱼比大型溞对三唑酮的毒性更敏感.比较不同测试终点,青鳉鱼的繁殖类指标最敏感,其次是生长、生存;相比大型溞的繁殖以及幼溞的生长,其幼溞的蜕皮次数指标更为敏感.因此,低剂量长期暴露下三唑酮会对水生生物的繁殖能力造成一定的损伤,评价其水生态安全应全面考虑不同生物种群的不同测试终点,尤其是鱼类繁殖毒性效应.     

Soil microbial response to herbicides applied to glyphosate-resistant canola

Adoption of glyphosate-resistant canola (Brassica napus L.) has increased glyphosate applications to this crop, and concerns have been raised about unintended consequences of these multiple applications. A field trial was conducted to evaluate the effects of pre-seed and in-crop glyphosate and alternative herbicides on soil microbial community functional structure, diversity and biomass. Pre-seed treatments were 2,4-D, glyphosate and 2,4-D + glyphosate, and in-crop treatments were glyphosate applied once, glyphosate applied twice, ethalfluralin, ethalfluralin + sethoxydim + ethametsulfuron + clopyralid, and sethoxydim + ethametsulfuron. Rhizosphere and bulk soil was collected at flowering stage of canola and analyzed for bacterial community-level substrate utilization patterns and microbial biomass C (MBC). Where differences were significant, pre-seed application of both 2,4-D and glyphosate altered the functional structure and reduced the functional diversity of soil bacteria, but increased MBC. These effects were not necessarily concurrent. The reduction in functional diversity was due to reduction in evenness, which means that the soil where both pre-seed herbicides had been applied was dominated by only few functional groups. In 1 year, two in-crop applications of glyphosate also reduced the functional diversity of soil bacteria when applied after pre-seed 2,4-D, as did in-crop sethoxydim + ethametsulfuron following pre-seed glyphosate. Even though significant differences between herbicides were fewer than non-significant differences, i.e., there were no changes in soil microbial community structure, diversity or biomass in response to glyphosate or alternative herbicides applied to glyphosate-resistant canola in most cases, the observed changes in soil microbial communities could affect soil food webs and biological processes.     

Exposure to phthalates: germline dysfunction and aneuploidy

Epidemiological studies continue to reveal the enduring impact of exposures to environmental chemicals on human physiology, including our reproductive health. Phthalates, a well characterized class of endocrine disrupting chemicals and commonly utilized plasticizers, are among one of the many toxicants ubiquitously present in our environment. Phthalate exposure has been linked to increases in the rate of human aneuploidy, a phenomenon that is detected in 0.3% of livebirths resulting in genetic disorders including trisomy 21, approximately 4% of stillbirths, and over 35% of miscarriages. Here we review recent epidemiological and experimental studies that have examined the role that phthalates play in germline dysfunction, including increases in apoptosis, oxidative stress, DNA damage, and impaired genomic integrity, resulting in aneuploidy. We will further discuss subject variability, as it relates to diet and polymorphisms, and the sexual dimorphic effects of phthalate exposure, as it relates to sex-specific targets. Lastly, we discuss some of the conserved effects of phthalate exposure across humans, mammalian models and nonmammalian model organisms, highlighting the importance of using model organisms to our advantage for chemical risk assessment and unveiling potential mechanisms that underlie phthalate-induced reproductive health issues across species.     

海上泄漏事故中有机化学品的理化行为、生态危害与污染控制综述

近几十年来,危险化学品的海上运输量不断增加,带来日益严重的泄漏风险,并危及海洋生态安全。但是,历史事件可作为未来有效应对海洋化学品泄漏事故的重要参考资料。因此,本文在统计29起典型海上泄漏事故案例相关信息基础上,对涉及的40种有机化学品在海洋中的环境行为、生态危害以及污染控制措施进行评述。主要结论如下:①根据入海后的物理行为,所有化学品（除了甲苯异氰酸酯与水反应外）划分为10类,其中,以沉降类（S）最多（14种）,易使底栖生物受到较大暴露风险。具有易燃/易爆性、腐蚀性的有机化学品分别为27和21种;②综合考虑生物蓄积性、生物降解性、急性毒性和慢性毒性,筛选出林丹、莠去津等16种具有高海洋生态危害性的有机化学品;③大多数有机化学品缺少海洋生物慢性毒性数据,需要进行更多研究以便为应急响应提供充分依据。④针对海上泄漏事故的污染控制技术主要包括源强控制、海上有机化学品回收、自然分散稀释三类。今后应重视污染海域生态修复技术的研究。     

离子对烷基化法在2,4-D和2,4,5-T残留分析中的应用

有机阴离子可以和长碳链的季胺盐阳离子结合生成可溶于高介电常数有机溶剂的离子对.在此溶剂中,它可以和某些卤代烃发生复分解反应,生成季铵盐阳离子的卤化物及有机阴离子的相应烷基化物,故称离子对烷基化反应.此反应条件温和,转化率高,被广泛地应用于酸性及其它含活泼氢的有机化合物的烷基衍生物合成中.在这类有机物的分析中也得到应用.但尚未见应用于农药及其降解物残留分析中的报道. 2,4-D,2,4,5-T是典型的酸性有机农药,广泛用作农田除草剂.在二者的残留分析中,通常用CH_2N_2、BF_3CH_3OH、(CH_3)_2SO_4将它们烷基化,然后用气相色谱加以分析.近几年也有人用多卤素取代醇的BCl_3络合物或五氟苄基溴化物同Na_2CO_3作为     

Chemicals,man and the environment

The interaction of chemicals with biological organisms is as old as life itself. Chemical pollution is usually considered to be human interference with natural chemical cycles and the release of man-made, unnatural compounds. The article traces five areas of chemical pollution and health hazards: air pollution, water pollution, occupational exposure, pollution from agricultural practices and contamination of food. It is suggested that historic perspective can aid in rational and prudent evaluation of present-day pollution problems.     

Exposure to endocrine disrupting chemicals perturbs lipid metabolism and circadian rhythms

A growing body of evidence indicates that exposure to environmental chemicals can contribute to the etiology of obesity by inappropriately stimulating adipogenesis as well as perturbing lipid metabolism and energy balance. One potential mechanism by which chemical exposure can influence lipid metabolism is through disturbance of circadian rhythms, endogenously-driven cycles of roughly 24hr in length that coordinate biochemical, physiological, and behavioral processes in all organisms. Here we show for the first time that exposure to endocrine disrupting compounds (EDCs), including the pesticide tributyltin, two commercial flame retardants, and a UV-filter chemical found in sunscreens, can perturb both circadian clocks and lipid metabolism in vertebrates. Exposure of developing zebrafish to EDCs affects core clock activity and leads to a remarkable increase in lipid accumulation that is reminiscent of the effects observed for longdaysin, a known disruptor of circadian rhythms. Our data reveal a novel obesogenic mechanism of action for environmental chemicals, an observation which warrants further research. Because circadian clocks regulate a wide variety of physiological processes, identification of environmental chemicals capable of perturbing these systems may provide important insights into the development of environmentally-induced metabolic disease.     

久效磷对秀丽隐杆线虫运动、学习和觅食行为的影响

久效磷(MCP)是一种广谱类内吸附性有机磷农药和潜在的神经毒剂,能够对非靶生物产生神经毒性作用,而行为毒性是神经毒性的主要表现形式. 以运动、学习与觅食行为、乙酰胆碱酯酶活性为指标,研究了久效磷对非靶生物——秀丽隐杆线虫(Caenorhabditis elegans,下称线虫)行为的影响. 结果显示:经0.5、5.0和50.0 mg/L久效磷暴露后,各暴露组线虫头部摆动和身体弯曲频率均极显著降低,0.5 mg/L暴露组线虫向前摆动频率显著减少,5.0和50.0 mg/L暴露组线虫向前摆动频率极显著减少;5.0和50.0 mg/L暴露组线虫在NaCl存在和缺少食物条件下,对NaCl的趋向性极显著升高;与对照组相比,50.0 mg/L暴露组线虫菌落接触率在2、4、6、8 h时均显著降低,在24 h时极显著降低;各暴露组线虫的乙酰胆碱酯酶活性均受到极显著抑制. 表明久效磷能够导致线虫运动、学习与觅食行为的严重缺陷,乙酰胆碱酯酶活性抑制与久效磷对线虫运动行为的影响呈正相关,与其学习行为的影响呈负相关.      

纳米四氧化三铁对2,4-D的降解研究

采用纳米Fe3O4降解溶液中的2,4-D,考察了2,4-D初始浓度、纳米Fe3O4的投加量、溶液pH对2,4-D降解效率的影响,并探讨了2,4-D的降解机理。实验结果表明,Fe3O4对2,4-D有明显的降解作用,纳米Fe3O4的降解效果优于微米级Fe3O4,降解过程中溶液中的氯离子浓度随着2,4-D的降解而升高,Fe3O4对2,4-D的降解机理是还原脱氯。当2,4-D初始浓度在0～10mg/L、纳米Fe3O4投加量0～300mg/L的范围内,2,4-D降解率随初始浓度和纳米Fe3O4投加量的增加而增大。在2,4-D初始浓度为10mg/L、pH3.0、纳米Fe3O4投加量300mg/L时降解效率最高,48h内2,4-D的降解率可达40%。     

新烟碱类杀虫剂污染特征及其毒性效应

综述了新烟碱类杀虫剂在土壤、水体和大气中的赋存现状及其对无脊椎动物、脊椎动物和人类的毒性效应.新烟碱类杀虫剂普遍存在于多介质环境中,特别在农业种植区具有较高的残留浓度.新烟碱类杀虫剂对非靶标动物的影响主要表现在氧化应激、抑制活动能力、损伤DNA和生育功能;亦会对人类的生育、生殖、神经以及脏器功能带来风险.因此,今后亟需系统研究新烟碱类杀虫剂在多环境介质中的赋存及污染状况,深入探讨新烟碱类杀虫剂对非靶标生物的健康危害,以便全面了解此类杀虫剂对生态环境及非靶标生物造成的潜在风险.     

Probabilistic ecological risk assessment for three chlorophenols in surface waters of China

Individual and combined assessment of risks of adverse effects to aquatic ecosystems of three chlorophenols (CPs), including 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP), were conducted. A probabilistic approach based on the concentrations of CPs in surface waters of China was used to determine the likelihood of adverse effects. The potential risk of CPs in surface waters of China was determined to be of concern, especially PCP and mixtures of CPs. The risks of adverse effects were examined as the joint probabilities of exposure and response. The joint probability for PCP was 0.271 in the worst case and 0.111 in the median case, respectively. Based on the cumulative probability, 5% of aquatic organisms included in the assessment would be affected 21.36% of the time in the worst case and 5.99% of the time in median case, respectively. For the mixtures of CPs, the joint probability were 0.171 in the worst case and 0.503 in median case, respectively and 5% of species would be affected 49.83% of the time for the worst case and 12.72% in the median case, respectively. Risks of effects of the individual CPs, 2,4-DCP and 2,4,6-TCP were deemed to be acceptable with a overlapping probability of < 0.1 with 5% of species being affected less than 4% of the time.     

蛋白核小球藻(Chlorella pyrenoidosa)微板毒性分析方法优化

以蛋白核小球藻(Chlorella pyrenoidosa,CP)为指示生物,96孔微板为暴露载体,污染物对藻的72 h生长抑制率为毒性指标,通过系统地检测蛋白核小球藻的生长曲线和吸收光谱,确定藻细胞密度和683 nm波长处光密度(D₆₈₃)之间的线性关系,考察不同初始藻密度、照度、暴露时间和暴露体积对藻生长的影响,建立了蛋白核小球藻微板毒性分析方法(CP-MTA法).将CP-MTA法应用于重金属盐、除草剂、杀虫剂以及离子液体等8种化学品对蛋白核小球藻的生长抑制毒性测试,以pEC₅₀为毒性指标,毒性大小顺序为敌草快>CuSO₄·5H₂O≈CdCl₂·2.5H₂O>氯化1-甲基-3-辛基咪唑(［Omim］Cl)>草甘膦>氯化1-甲基-3-丁基咪唑(［Bmim］Cl)>敌敌畏>乐果,与文献结果一致.CP-MTA法由于以微板为反应载体,所需样品少,便于多次平行,数据重复性好.      

Persistence and mobility of 2,4-D in unsaturated soil zone under winter wheat crop in sub-tropical region of India

The present study was undertaken to determine the persistence and mobility of 2,4-dichlorophenoxy acetic acid (2,4-D) in unsaturated soil zone under real field conditions for the wheat crop in Roorkee, India. Three experimental plots were chosen in the agricultural field itself to represent the real field conditions in the study area and the potential movement and persistence of herbicide 2,4-D was investigated under three different irrigation treatments. The presence of herbicide along with soil water content was determined in soil at different depths at a temporal scale. The movement of the herbicide was also simulated numerically by solving the coupled soil water content movement and mass transport equations using HYDRUS-1D. The measured soil water content trends and the 2,4-D concentration profiles showed a good agreement with the numerically simulated results. The maximum effect of the herbicide was primarily retained up to 15 cm of the soil profile. The current existing dosage of 0.5 kg ha⁻¹ of pesticide was found to be safe to avoid soil contamination as no residue of 2,4-D was traced at the end of the wheat crop season in any of the plots. Higher concentrations of 2,4-D were also simulated numerically and the simulated results showed that the safe dosage of pesticide application would depend on irrigation treatments.     

Atrazine accumulation and toxic responses in maize Zea mays

Atrazine accumulation, oxidative stress, and defense response in maize seedlings exposed to extraneous atrazine were studied. Accumulation of atrazine in maize increased with increasing exposure concentration. The abscisic acid (ABA) content was positively correlated with the atrazine concentrations in maize roots and shoots (p < 0.05). Hydroxyl radical (·OH) in maize was determined in vivo with electron paramagnetic resonance spectroscopy. Its intensity was positively correlated with atrazine concentration in roots and shoots (p < 0.05), and higher level of ·OH generated in roots than in shoots corresponded to the major accumulation of atrazine in roots. Superoxide dismutase, peroxidase and catalase in roots were up-regulated by atrazine exposure at 1 mg/L compared to the control and malondialdehyde content in roots was enhanced when atrazine exposure concentration reached 10 mg/L. These results suggested the exposure and accumulation of atrazine caused oxidative toxicity and antioxidant response in maize.     

2,4-D完全抗原的合成及其免疫性能评价

以2,4-D为半抗原,BSA为载体蛋白,通过EDC的偶联反应条件优化试验,合成了多种结合比的完全抗原,制备了小分子环境污染物的多克隆抗体.结果表明,偶联反应优化步骤是2,4-D、BSA和EDC同时反应,4°C条件下反应18h.偶联反应可以在2,4-D的浓度为10.0～12.0 mg/mL的0.05mol/L的磷酸盐缓冲溶液中进行,反应缓冲体系pH控制在5.4～6.1之间.EDC的加入量低于12 mg时,采用2,4-D和多聚赖氨酸的偶联物为包被抗原.通过balb/c小鼠免疫试验评价结合比分别为6、12、18和25的完全抗原的免疫性能,结果表明结合比为12和18的完全抗原具有很好的免疫原性.其中以结合比为18的完全抗原免疫小鼠获得的抗血清对包被抗原载体的非特异性吸附低于阴性血清,2,4-D特异性血清含量高,适于作为完全抗原免疫小鼠进一步制备单克隆抗体.     

海河悬浮颗粒物影响阿特拉津对斑马鱼的急性毒性研究

悬浮颗粒物对有机污染物的吸附降低了其表观生物富集系数,这一过程是否同时能够减弱有机污染物对水生生物的毒性却少有报道.因此,本研究选取海河干流二道闸沉积物为悬浮颗粒物,以阿特拉津为目标污染物,斑马鱼为目标生物,进行急性毒性试验.结果表明,无悬浮颗粒物时,阿特拉津对斑马鱼的96 h半致死浓度(96h-LC50)为29.06 mg·L-1,95%置信区间为24.41~40.70 mg·L-1,悬浮颗粒物浓度为7500mg·L-1和15000 mg·L-1时这一指标分别为30.74 mg·L-1和39.51 mg·L-1,对应的95%置信区间分别为27.17~40.91 mg·L-1和30.43~126.93 mg·L-1.并且无悬浮颗粒物、7500 mg·L-1悬浮颗粒物、15000 mg·L-1悬浮颗粒物3组染毒系列中出现的最大无效应浓度分别为3、9和15 mg·L-1.研究表明,悬浮颗粒物的存在降低了阿特拉津对斑马鱼的急性毒性.     

The mechanism of different cyanobacterial responses to glyphosate

Glyphosate, the most extensively used herbicide globally, has raised ecotoxicological concerns because it can be transported into the aquatic environment and cause adverse effects on the aquatic system. However, the functional mechanism of glyphosate on cyanobacteria are not completely disentangled. In this study, we selected six common cyanobacteria to evaluate glyphosate effects on cyanobacterial growth in monoculture experiment. Results showed that the growth of five tested cyanobacterial species were promoted under different degrees, and only Pseudanabaena was inhibited by glyphosate. In the phylogenetic tree based on gene sequences of 5-enol-pyruvylshikimate-3-phosphate synthase (EPSPS), a target for glyphosate, we found that the position of Pseudanabaena is the closest to plant, which was sensitive to glyphosate, thereby explaining the inhibitory effect of Pseudanabaena following glyphosate exposure. The primary degraded metabolites or analogs did not induce cyanobacterial growth, laterally demonstrating that glyphosate was used as a source of phosphorus to accelerate cyanobacterial growth because phosphorus levels increased in the medium of glyphosate treatment. Overall, this study provides a better understanding of the influence of glyphosate on the composition of aquatic microbiota and explains the mechanism of cyanobacterial response to glyphosate.     

NC-PC锚定微量Fe活化PMS降解水中2,4-二氯苯氧乙酸

采用分步热分解法制备了NC-PC（三维多孔碳材料）锚定的微量Fe基催化剂,用于活化过一硫酸盐（PMS）氧化降解水中2,4-二氯苯氧乙酸（2,4-D）.采用透射电子显微镜（TEM）、高精度比表面积仪（BET）、X射线光电子能谱分析（XPS）和电感耦合等离子体发射光谱分析（ICP）对催化剂进行表征.考察了不同金属、制备方法、催化剂投加量、PMS投加量、初始pH值以及水中不同阴离子（Cl^-、NO₃^-、HCO₃^-）对2,4-D降解的影响.结果表明,通过热分解法合成的Fe-NC-PC对2,4-D具有更好的降解效果,当2,4-D初始浓度为0.1mmol/L,初始pH=3.4,催化剂投加量0.15g/L,PMS浓度0.7mmol/L时,反应20min内2,4-D的去除率可达91%.随着催化剂投加量、PMS投加量的提高,2,4-D的降解效果提高;随着初始pH值的提高,2,4-D的降解效率逐渐降低;水中不同阴离子（Cl^-、NO₃^-、HCO₃^-）和腐殖酸（HA）对2,4-D的降解有轻微的抑制作用.通过自由基淬灭实验、EPR测试以及XPS分析了反应的主要活性物种和反应机理,发现材料制备过程中形成的Fe-N_x是主要的反应活性位,能够有效的活化PMS降解水中2,4-D,¹O₂在2,4-D的降解过程中起到主要作用.     

两种微藻胞外分泌物与NO2-、NO3-对2，4-D光解的影响

在模拟太阳光照射下,利用旋转式光化学反应装置,研究了海水小球藻(Chlorella vulgaris)和新月菱形藻(Nitzschia closterium)的胞外分泌物(EOM),以及分别在NO-2或(和)NO-3共存条件下对2,4-二氯苯氧乙酸(2,4-D)光解的影响.实验结果表明,2,4-D在海水小球藻和新月菱形藻EOM及分别在NO-2、NO-3共存下的光解过程均符合准一级动力学反应.研究发现,2,4-D的光解速率随海水小球藻和新月菱形藻EOM浓度的增加而减小,表明这两种微藻EOM可抑制海水中2,4-D的光解.当在微藻EOM溶液中分别加入不同浓度的NO-2或NO-3后,微藻EOM对2,4-D光解的抑制作用减弱,且随着NO-2和NO-3浓度的增加,2,4-D光解速率明显增加.特别是当微藻EOM与NO-2或NO-3三者共存时,可进一步促进2,4-D的光解.