石化废水生化处理前后抗雌激素活性的变化

以某企业的石化废水处理工艺为对象,利用固相萃取-双杂交酵母法,对混入和未混入苯胺废水2种典型工况下进、出水的抗雌激素活性进行了研究,以了解不同性质废水的混合处理对石化废水抗雌激素活性的影响规律. 结果表明,现有的废水处理系统能有效降低有机物浓度,2种典型工况下溶解性有机碳(DOC)的去除率分别可达72%和74%,但生成了更具抗雌激素活性的物质. 在混入苯胺废水的工况下,出水的抗雌激素活性显著高于进水,为进水的2.8倍. 进一步研究废水中不同组分的抗雌激素活性发现,苯胺废水中的疏水性物质是导致出水抗雌激素活性升高的主要原因.      

Degradation of nitrobenzene in wastewater by γ-ray irradiation

The degradation of nitrobenzene(NB) by γ-ray irradiation was studied. The influences of dose rate and initial NB concentration were investigated in details. At a dose rate of 55 Gy/min, the degradation kinetics was pseudo-first-order at NB concentrations from 0.2 mmol/L to 4.0 mmol/L. At an initial NB concentration of 0.8 mmol/L, the degradation of NB at various dose rates also followed pseudo-first-order kinetics. Dissolved oxygen was found to have a positive effect on NB degradation. The degradation products were identified as nitrophenol,nitrosobenzene, and hydroquinone, and so on. Based on the product analysis, possible degradation pathways of nitrobenzene were proposed.     

Identification of differentially expressed genes response to TCDD in rat brain after long-term low-dose exposure

Several cohort studies have reported that dioxin and dioxin-like polychlorinated biphenyls might impair the nervous system and lead to neurological or neurodegenerative diseases in the elder people, but there is limited research on the involved mechanism. By using microarray analysis, we figured out the differentially expressed genes between brain samples from SD rats after low-dose(0.1 μg/(kg?bw)) dioxin exposure for six months and controls. To investigate the function changes in the course of dioxin exposure, Gene Ontology(GO) annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analysis were performed on the differentially expressed genes. And the changes of several picked genes have been verified by real-time PCR. A total of 145 up-regulated and 64 down-regulated genes were identified. The metabolic processes, interleukin-1 secretion and production were significantly associated with the differentially expressed genes. And the genes regulated by dioxin also clustered to cholinergic synapse and long-term potentiation. Candidate biomarker genes such as egr1, gad2, gabrb3, abca1, ccr5 and pycard may be toxicological targets for dioxin. Furthermore, synaptic plasticity and neuro-immune system may be two principal affected areas by dioxin.     

环境汞污染暴露下大鼠肝中一氧化氮及一氧化氮合酶的变化

为了探讨汞污染暴露对公众健康的潜在危害,采用清镇化工地区汞污染粮食对大鼠进行暴露试验,研究不同暴露时间节点处大鼠肝中一氧化氮(NO)和一氧化氮合酶(NOS)的变化,并以市售上海粮食作对照.结果表明,利用汞污染的粮食对大鼠暴露7 d后,大鼠肝中NO含量及NOS活力出现显著升高(p＜0.05).7～30 d暴露与长时间暴露90 d情况相比,肝中NO含量相对稳定.对大鼠肝中汞、硒元素的分析表明,汞、硒元素含量间有相关关系(r=0.9426),表明硒元素对汞的毒性作用有一定影响.长期暴露90 d后,肝中NO含量出现急剧上升,与对照组相比上升200%.同时,体内脂质过氧化产物丙二醛(MDA)含量也出现显著升高(P＜0.05),表明长期暴露引起了机体的氧化损伤.     

Assessment of potential dermal and inhalation exposure of workers to the insecticide imidacloprid using whole-body dosimetry in China

In China, although improvements to the pesticide registration process have beenmade in last thirty years, no occupational exposure data are required to obtain a commercial license for a pesticide product. Consequently, notably little research has been conducted to establish an exposure assessment procedure in China. The present study monitored the potential dermal operator exposure from knapsack electric sprayer wheat field application of imidacloprid in Liaocheng City, Shandong Province and in Xinxiang City, Henan Province, China, using whole-body dosimetry. The potential inhalation exposure was determined using a personal air pump and XAD-2 sample tubes. The analytical method was developed and validated, including such performance parameters as limits of detection and quantification, linear range, recovery and precision. The total potential dermal and inhalation exposures were 14.20, 16.80, 15.39 and 20.78 mL/hr, respectively, for the four operators in Liaocheng and Xinxiang, corresponding to 0.02% to 0.03% of the applied volume of spray solution. In all trials, the lower part (thigh, lower leg) of the body was the most contaminated, accounting for approximately 76% to 88% of the total exposure. The inhalation exposure was less than 1% of the total exposure. Such factors as the application pattern, crop type, spray equipment, operator experience and climatic conditions have been used to explain the exposure distribution over the different parts of the body. As indicated by the calculated Margin of Exposure, the typical wheat treatment scenarios when a backpack sprayer was used are considered to be safe in terms of imidacloprid exposure.     

Assessment of potential dermal and inhalation exposure of workers to the insecticide imidacloprid using whole-body dosimetry in China

In China, although improvements to the pesticide registration process have been made in la thirty years, no occupational exposure data are required to obtain a commercial license for pesticide product. Consequently, notably little research has been conducted to establish a exposure assessment procedure in China. The present study monitored the potential derm operator exposure from knapsack electric sprayer wheat field application of imidacloprid Liaocheng City, Shandong Province and in Xinxiang City, Henan Province, China, usin whole-body dosimetry. The potential inhalation exposure was determined using a person air pump and XAD-2 sample tubes. The analytical method was developed and validate including such performance parameters as limits of detection and quantification, linear rang recovery and precision. The total potential dermal and inhalation exposures were 14.20, 16.815.39 and 20.78 m L/hr, respectively, for the four operators in Liaocheng and Xinxian corresponding to 0.02% to 0.03% of the applied volume of spray solution. In all trials, the low part(thigh, lower leg) of the body was the most contaminated, accounting for approximate76% to 88% of the total exposure. The inhalation exposure was less than 1% of the tot exposure. Such factors as the application pattern, crop type, spray equipment, operat experience and climatic conditions have been used to explain the exposure distribution ov the different parts of the body. As indicated by the calculated Margin of Exposure, the typic wheat treatment scenarios when a backpack sprayer was used are considered to be safe terms of imidacloprid exposure.     

电子束辐照降解水体中的金霉素

应用电子加速器辐照研究了去除水体中金霉素（30mg/L）的过程,初步探索了剂量、不同气氛条件下叔丁醇的存在、pH值、无机阴离子等对去除效率的影响.然后根据实验结果推测了降解机理和降解产物毒性.结果表明：电子束辐照能高效去除水体中的金霉素,且还原性粒子占主导作用;pH值为碱性时利于金霉素的去除;0.005mol/LCO₃^2-、SO₄^2-、NO₃^-或Cl^-的存在能促进其去除.根据超高效液相色谱-质谱（UHPLC-MS）对降解产物的分析,并结合理论计算推测出10种降解产物和相应的降解途径.之后的费氏弧菌毒理实验数据显示：降解后水样的生物毒性随着吸收剂量先增高后缓慢降低,但辐照5.0kGy后毒性依然较大.     

电子束辐照降解水中氯霉素的研究

本研究对氯霉素(CAP)在不同条件下的电子束辐照降解进行了研究.结果表明,电子束辐照可有效去除水中CAP,低浓度CAP在酸性条件下的辐照降解更为显著,且降解过程符合准一级动力学模型.通过添加不同的自由基清除剂,发现HO·在CAP降解中起关键作用,此外,CAP分子也会吸收辐照而发生分解.水中共存的阴离子和腐殖酸(HA)对CAP辐照降解均有抑制作用,这跟其与HO·的反应速率常数大小有关,并且反应速率越大,其抑制能力越强.CAP在去离子水中的去除率高于其他实际水体,但辐照剂量为4 k Gy时,污水厂污水过滤水和胶体浓缩液中的CAP也可分别去除89.1%和81.7%.利用GC-MS检测到辐照后溶液中有6种中间产物,主要是通过脱水、不对称中心断键和脱酰胺作用形成.此外,IC检测有Cl-、NO-3和NO-2的产生,并且TOC在一定程度上降低,说明部分CAP被矿化.     

氰化钠溶液的电子束辐照降解

研究了利用电子束辐照降解氰化钠水溶液的效果.分别考察了CN-初始浓度、溶解氧浓度、辐照剂量率对 CN-降解效果的影响.采用总有机碳(TOC)分析仪、离子色谱仪(IC)、紫外分光光度计等分析了 CN-在不同实验条件下的辐照降解产物.实验结果表明,电子束能有效降解水溶液中的 CN-,较低的 CN-初始浓度,较高的辐照剂量,较高的溶解氧浓度以及较低的辐照剂量率能够提高CN-降解效率.CN-辐照后转化为 NH3、NO3-、NO2-、碳酸盐和有机物.     

超声灭活饮用水中隐孢子虫研究

为研究超声对饮用水中隐孢子虫(Cryptosporidium parvum)的灭活情况,考察了超声频率、功率、pH值和温度对灭活率的影响,通过形态学观察初步探讨了超声灭活隐孢子虫的机制,并进行了灭活动力学分析.结果表明,低频有利于隐孢子虫灭活,19.8kHz, pH7.2,温度(20±1)℃条件下超声15min灭活率可达92.5%,频率升高灭活率反而下降.在本实验条件下,超声功率103W对隐孢子虫的灭活效果与151W的相近,pH值对超声灭活隐孢子虫的影响不大,36℃超声灭活15min灭活率为95.6%,而在9℃下超声15min灭活率为88.3%,水温升高有利于灭活.灭活前后的形态学变化表明超声空化作用导致细胞膜破坏,细胞质流出从而起到灭活孢囊的效果.超声灭活隐孢子虫遵循假一级反应动力学,灭活隐孢子虫以低频率高功率的效果最好,可认为隐孢子虫的灭活以超声空化的强度为主.     

SO2吸入对大鼠海马组织炎性因子水平、钙稳态和即早基因表达的影响

采用动式熏气法研究了不同浓度SO2(7、14、28和56 mg·m-3)吸入对大鼠海马组织炎性因子白介素-1β(Interleukin-1β,Ⅱ-1β)、肿瘤坏死因子(Tumor Necrosis Factor-a,TNF-a)水平、神经元胞内游离Ca2 浓度以及即早基因c-fos和e-jun mRNA表达的影响,结果表明:SO,可造成海马组织Ⅱ-1β(p<0.01)和TNF-α(p<0.05)水平显著增高,但低浓度下(7、14 mg·m-3)作用较为明显;so2可显著增加神经元胞内钙离子浓度,上调c-fos和c-jun mRNA的表达,且呈现出明显的剂量-效应关系.这一结果从整体水平上说明了SO2对中枢神经系统的损伤效应,并提示其可能的分子机制与炎性反应、钙离子稳态及即早基因表达相关.     

亚慢性全氟辛烷磺酸染毒对大鼠海马细胞钙稳态的影响

采用经口摄食染毒,探讨全氟辛烷磺酸(PFOS)对大鼠血清与脑组织中PFOS浓度及海马细胞内钙离子浓度([Ca2+]i)的影响,观察大鼠大脑皮质、海马和小脑组织病理学变化.结果表明,染毒组大鼠血清与脑组织中PFOS浓度、海马细胞内[Ca2+]i均显著高于对照组,且随着染毒剂量的升高,海马细胞内[Ca2+]i升高.大鼠血清与脑组织中PFOS浓度、脑组织中PFOS浓度与海马细胞[Ca2+]i均呈现显著的正相关关系.染毒组大鼠大脑皮质、海马和小脑组织中未见尼氏体染色变浅等病理性改变.