环境中双酚A污染现状及其对孤独症患儿神经免疫系统的毒性作用研究

孤独症(Autism spectrum disease,ASD)是一种小儿广泛性的发育障碍.尽管ASD病因目前尚无最终定论,普遍接受的观点是,ASD同时受到遗传和环境因素两方面的作用,而近年ASD发病率的爆发式增长已明显偏离了哈代-温伯格平衡,这提示环境污染很可能是导致发病率异常增快的罪魁祸首,是更值得我们关注的因素.针对该问题,综述了新型污染物双酚A在环境中的污染状况以及空气、水与日常食物中双酚A污染的水平,探讨了人体双酚A暴露的途径以及环境中双酚A污染对ASD患儿神经免疫系统的影响.提出了应加强对环境中双酚A污染的调查研究,开展人体双酚A暴露的潜在风险评估,为保证居民尤其是婴幼儿的健康提供科学依据.     

双酚-A和17β-雌二醇对人乳腺癌细胞生长的影响

通过MTT-细胞增殖活性测定法和双参数流式细胞光度术研究了双酚-A和17b-雌二醇对人乳腺癌细胞株MCF-7增殖、细胞周期以及核酸和蛋白合成的影响.结果表明,在310^-16～310^-8mol/L范围内,双酚-A和17b-雌二醇都能促进细胞增殖;在310^-14mol/L时,细胞增殖活性达到最高值.当作用浓度为310^-14mol/L时,细胞周期的S期比例增加,细胞总蛋白表达量明显增加.统计结果表明,双酚-A和17b-雌二醇对MCF-7细胞生长特性的雌激素效应非常相似.     

罐头食品又一污染源

据最新的调查表明,超级市场货架上的许多罐头食品含有少量的雌激素类污染物。这种被称为双酚A(BPA)的雌激素类污染物显然是从罐头盒内层涂布的塑料树脂溶滤出来的。由于最近的研究,开始将这种遍地都有的污染物与乳腺癌和生育异常的危险性增高联系起来,故对雌激素类污染物的暴露已越来越引起人们的关注。过去4年,内分泌学家已鉴定出能排出雌激素类成分的两类塑料树脂。     

双酚A类似物的雄性生殖毒性研究进展

聚焦BPA类似物对雄性动物的生殖毒性研究,分析双酚S、双酚F、双酚AF、双酚B和双酚E对哺乳类实验动物睾丸及组织结构、附睾重量及组织学结构、激素水平、精子参数等常规指标的影响,考察关于鱼类和两栖类动物的研究.研究发现,不管暴露剂量高低、暴露方式的差异或是动物种属的不同,所有BPA类似物的暴露都显示阳性结果,这与BPA雄性生殖毒性尚有争议的事实形成对比,暗示这些BPA类似物具有比BPA更明显的雄性生殖毒性.总体来看,目前的BPA类似物雄性生殖毒性的数据只局限在有限的几个实验室,且实验的质量控制难以评价.因此,BPA类似物的雄性生殖毒性的数据还需要更多实验室的验证,并且过程中需要严格控制动物实验的质量,以获得更加可靠且可重复的结果.     

二氧化钛光催化降解双酚AF研究

系统研究了双酚AF在二氧化钛溶液中的光催化降解行为。就溶解氧、二氧化钛投加量、氟离子浓度和双酚AF的初始浓度等因素对双酚AF降解的影响进行了详细讨论。研究重点是双酚AF的降解动力学以及在降解过程中所产生的氟离子浓度。当双酚AF的初始浓度是40μmol/L时,经过540 min的光催化降解,反应体系的总有机碳去除率超过97%,此时溶液中氟离子的浓度为0.98 mg/L。双酚AF在二氧化钛溶液中的降解符合Langmuir-Hinshelwood动力学模型,其降解动力学常数是1.21μmol/(L·min)。结果表明,二氧化钛光催化可以有效的去除双酚AF,并且不产生其它二次污染物。     

珠江三角洲地区大气污染对人群健康的影响

在珠江三角洲地区选取广州麓湖等16个典型站点,观测了珠江三角洲地区2006年大气污染物浓度.结果表明,珠江三角洲地区2006年PM10、PM2.5、SO2、NO2、O3年日均浓度分别达到75,56,57,53,44μg/m3.搜集国内PM10、PM2.5、SO2、NO2、O3暴露人群健康影响的流行病学研究资料,利用Meta分析方法获取我国人群大气污染物暴露对死亡健康结局影响的暴露-反应关系,并以珠江三角洲地区人群2006年大气污染物暴露浓度为基准,运用泊松回归模型评价珠江三角洲地区大气污染对人群的健康影响.     

基于人体健康风险的水污染事件污染物安全阈值研究

水污染事件急性人体健康风险评估是环境科学的一个新兴研究领域.在简要介绍污染物急性风险评估方法的基础上,建立了水污染事件特征污染物安全阈值的计算模型.根据水污染事件特征污染物安全阈值计算方法,对我国2000～2010年间发生的主要水污染事件特征污染物的急性暴露安全阈值进行研究.结果表明不同水污染事件特征污染物的急性暴露安全阈值:氰化钠、镉、甲醛、氨氮、甲苯、硝基苯、微囊藻毒素-LR分别为0.1、0.6、8、20、6、0.07、0.004 mg.L-1.比较了急慢性安全阈值计算方法,其差异性在于污染物毒理学范围不同、饮用水暴露比例不同、暴露敏感人群不同.     

溴代阻燃剂TBBPA最新研究进展

四溴双酚A是使用量较大的一种溴代阻燃剂,具有生物毒性,是最近十几年的热门研究污染物。对最近三年(2013—2015年)来四溴双酚A的最新研究进展进行了综述,主要从环境中分布、检测分析研究,毒性、毒理研究,降解、去除技术研究等3方面进行阐述,总结了研究中存在的问题与新的发展方向。     

我国近岸海域优先控制有机污染物的筛选

针对当前我国海洋环境中有机污染现状和监测评价的需求,本文借鉴国内外研究经验,以我国近岸海域有机污染物的环境分布浓度、污染物的急慢性毒性和理化性质为评价赋值指标,建立了基于环境暴露指数和环境效应指数为基础的优先控制有机污染物定量筛选方法.利用本筛选方法,尝试性的提出了我国近岸海域优先控制有机污染物名单,以此为海洋管理部门...     

国内空气污染暴露水平评价方法研究进展

该文介绍了暴露评价的概念及大气污染物暴露评价常用的方法,包括模型评价法(土地利用回归模型、大气扩散模型、插值模型和邻近性模型)、污染物监测法(个体暴露水平监测、微环境监测结合时间-活动模式、固定监测站监测法)、生物标志检测法等,并对各种方法的优缺点进行了总结分析,最后指出了中国目前大气污染物暴露评价研究的不足之处并对其前景进行了展望。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

ＲｅｍｏｖａｌｏｆｈｅａｖｙｍｅｔａｌｓｆｒｏｍｓｅｗａｇｅｓｌｕｄｇｅｂｙｌｏｗｃｏｓｔｉｎｇｃｈｅｍｉｃａｌｍｅｔｈｏｄａｎｄｒｅｃｙｃｌｉｎｇｉｎａｇｒｉｃｕｌｔｕｒｅＷｕＱｉｔａｎｇ，ＮｙｉｒａｎｄｅｇｅＰａｓｃａｓｉｅ，ＭｏＣｅｈｕｉＦ...     

Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.