Re-evaluation of thyroid hormone signaling antagonism of tetrabromobisphenol A for validating the T3-induced Xenopus metamorphosis assay

We developed the T3-induced Xenopus metamorphosis assay, which is supposed to be able to sensitively detect thyroid hormone(TH) signaling disruption of chemicals. The present study aimed to validate the T3-induced Xenopus metamorphosis assay by re-evaluating the TH signaling antagonism of tetrabromobisphenol A(TBBPA), a known TH signaling disruptor. According to the assay we developed, Xenopus tadpoles at stage 52 were exposed to 10–500 nmol/L TBBPA in the presence of 1 nmol/L T3. After 96 hr of exposure, TBBPA in the range of 10–500 nmol/L was found to significantly inhibit T3-induced morphological changes of Xenopus tadpoles in a concentration-dependent manner in term of body weight and four morphological endpoints including head area(HA), mouth width(MW), unilateral brain width/brain length(ULBW/BL), and hind-limb length/snout-vent length(HLL/SVL).The results show that these endpoints we developed are sensitive for characterizing the antagonistic effects of TBBPA on T3-induced metamorphosis. Following a 24-hr exposure,we found that TBBPA antagonized expression of T3-induced TH-response genes in the tail,which is consistent with previous findings in the intestine. We propose that the tail can be used as an alternative tissue to the intestine for examining molecular endpoints for evaluating TH signaling disruption. In conclusion, our results demonstrate that the T3-induced Xenopus metamorphosis assay we developed is an ideal in vivo assay for detecting TH signaling disruption.     

北京市郊区夏季臭氧重污染特征及生成效率

为研究北京郊区夏季O₃(臭氧)重污染过程特征及O₃生成的光化学敏感性,基于2016年夏季在北京郊区开展的针对O₃及其相关污染物的强化观测试验(7月23日—8月31日,共计40 d),分析了观测期间O₃浓度[以φ(O₃)计]变化特征、O₃重污染过程主控因素与O₃敏感性化学特征.结果表明:观测期间φ(O₃)超标时有发生,最大小时φ(O₃)为151.1×10-9,其中有15 d的φ(O₃)最大8 h滑动平均值(O₃-max-8h)超过了GB 3095—2012《环境空气质量标准》二级标准限值,占观测天数的37.5%;不同O₃重污染过程成因有所不同,城市烟羽传输的污染物对郊区O₃重污染过程影响显著(观测期间臭氧重污染过程:过程1,7月27—29日;过程3,8月9—11日;过程4,8月16日;过程5,8月21—24日),区域光化学污染对郊区O₃重污染过程也有贡献(观测期间O₃重污染过程2:8月4—6日);结合后向气流轨迹进一步辅助说明了不同重污染过程中O₃的来源不同.研究还发现,观测区域存在反“周末效应”现象,说明观测区域周末受人为影响较为明显;基于观测数据计算的OPE(O₃生成效率)分析了O₃光化学敏感性表明,在有OPE值的22 d内NO_x控制区和VOCs控制区出现的概率(41%)相等,即观测区域O₃对NO_x和VOCs均敏感;此外还发现,在O₃重污染过程中光化学敏感性会随其反应进程发生改变,由NO_x控制区逐渐转变为VOCs控制区.      

潜流人工湿地处理地下水TCE污染实验研究

分别构建无植物、宽叶香蒲和芦苇3组潜流人工湿地系统,研究潜流人工湿地对受到TCE(三氯乙烯)污染地下水的处理效果。实验结果表明:无植物湿地系统和芦苇湿地系统的出水TCE去除率波动较大,香蒲湿地系统出水TCE去除率相对稳定,其出水TCE平均去除率为77.7%,最大值为87.5%,最小值为70.7%。对于无植物湿地系统,湿地床中层和下层的TCE去除率相差较大,而该差异在香蒲和芦苇湿地系统中并不明显。在湿地系统中TCE沿水平方向的降解反应基本符合一级反应动力学模型。     

基于主成分分析法的陕北地区可持续发展对比研究

基于可持续发展基本理论,选取60项指标建立陕北地区可持续发展评价指标体系,采用软件SPSS(19.0)进行主成分分析,分别对延安市、榆林市2000—2014年的可持续发展水平、可持续发展潜力和可持续发展协调度进行动态对比分析。结果表明延安市、榆林市发展基本趋于一致:可持续发展水平较高,但可持续发展潜力明显不足,可持续发展协调度较低;制约其可持续发展的主要因素在于资源发展动力不足、产业结构单一、环境的恶化及治理的低效。     

梁平县境内高滩河水质的空间分布及其对土地利用方式的响应

以梁平县境内高滩河流域为研究对象,综合应用GIS空间分析、Pearson相关分析和RDA冗余分析方法,研究在子流域尺度上COD、BOD5、氨氮和总磷4种水质要素对土地利用方式的生态响应。结果表明:高滩河流域土地利用类型对水质要素有着重要影响,林地能够改善河道水环境,旱地和城镇村和工矿用地是COD、BOD5和氨氮的主要污染来源,园地、交通运输用地以及水域对污染物的影响较弱,说明农业面源污染和农村居民生活污染是高滩河水质恶化的主要原因。     

Bioaccumulation and the expression of hepatic cytochrome P450 genes in marine medaka (Oryzias melastigma) exposed to difenoconazole

This study was conducted to assess the effects of difenoconazole (DFZ), a triazole fungicide, on the hepatic biotransformation system and its bioaccumulation in marine medaka (Oryzias melastigma). Fish were exposed to DFZ (1, 10, 100, 1000 ng/L) for 180 days. The results showed that: (1) The mRNA levels of hepatic CYP1A1, CYP1B, CYP1C1, CYP27B and CYP3A40 were up-regulated, but those of CYP3A38 and CYP27A1 were down-regulated. (2) The activity of ethoxyresorufin-O-deethylase (EROD) and the content of reduced glutathione (GSH) in the liver were increased in the DFZ-treated groups, and glutathione S-transferase (GST) activity was increased in the 100 and 1000 ng/L groups. (3) DFZ was accumulated in the muscle and the biological concentration factors in the 10, 100, and 1000 ng/L groups were respectively 149, 81 and 25. These results suggested that long-term exposure to DFZ at low concentrations would result in a bioaccumulation of this compound and disturb the biotransformation system.     

Amoxicillin effects on functional microbial community and spread of antibiotic resistance genes in amoxicillin manufacture wastewater treatment system

This study aimed to reveal how amoxicillin(AMX) affected the microbial community and the spread mechanism of antibiotic resistance genes(ARGs) in the AMX manufacture wastewater treatment system. For this purpose, a 1.47 L expanded granular sludge bed(EGSB) reactor was designed and run for 241 days treating artificial AMX manufacture wastewater. 454 pyrosequencing was applied to analyze functional microorganisms in the system. The antibiotic genes OXA_(-1), OXA_(-2), OXA_(-10), TEM_(-1), CTX-M_(-1), class I integrons(intI1) and 16 SrRNA genes were also examined in sludge samples. The results showed that the genera Ignavibacterium, Phocoenobacter,Spirochaeta, Aminobacterium and Cloacibacillus contributed to the degradation of different organic compounds(such as various sugars and amines). And the relative quantification of eachβ-lactam resistance gene in the study was changed with the increasing of AMX concentration.Furthermore the vertical gene transfer was the main driver for the spread of ARGs rather than horizontal transfer pathways in the system.     

Determination of 15 phthalate esters in air by gas-phase and particle-phase simultaneous sampling

Based on previous research, the sampling and analysis methods for phthalate esters (PAEs) were improved by increasing the sampling flow of indoor air from 1 to 4 L/min, shortening the sampling duration from 8 to 2 hr. Meanwhile, through the optimization of chromatographic conditions, the concentrations of 9 additional PAE pollutants in indoor air were measured. The optimized chromatographic conditions required a similar amount of time for analysis as before, but gave high responsivity, the capability of simultaneously distinguishing 15 kinds of PAEs, and a high level of discrimination between individual sample peaks, as well as stable peak generation. The recovery rate of all gas-phase and particle-phase samples of the 15 kinds of PAEs ranged from 91.26% to 109.42%, meeting the quantitative analysis requirements for indoor and outdoor air sampling and analysis. For the first time, investigation of the concentration levels as well as characteristics of 15 kinds of PAEs in the indoor air from four different traffic micro-environments (private vehicles, busses, taxis and subways) was carried out, along with validation of the optimized sampling and analytical method. The results show that all the 9 additional PAEs could be detected at relatively high pollution levels in the indoor air from the four traffic micro-environments. As none of the pollution levels of the 15 kinds of PAEs in the indoor air from the 4 traffic micro-environments should be neglected, it is of great significance to increase the types of PAEs able to be detected in indoor air.     

恶臭污染排放源指纹谱编制及初步应用

为了识别恶臭污染源排放特征以及了解不同行业恶臭物质排放差异,对恶臭污染排放源指纹谱指标物质进行了筛选,并依据筛选结果对6家典型恶臭排放企业进行样品采集及分析,绘制了各家企业的指纹谱图.结果表明:①通过物质嗅觉阈值与AMGE（ambient multimedia environmental goals,周围环境目标值）和RfC（reference concentration,健康风险参考浓度）对比以及结合国内外恶臭标准受控物质和现有的标准检测方法,最终确定了包括三甲胺、硫化氢、甲硫醇等典型恶臭物质在内的19种物质作为指纹谱指标物质.②依据我国现行的标准监测分析方法对19种恶臭指标物进行检测,初步得到了各家企业的恶臭物质指纹谱数据,绘制了各家企业的指纹谱图.③指纹谱成分分析结果显示,污水处理厂主要的恶臭物质是硫化氢,ρ（硫化氢）为44.566 mg/m3;涂料企业ρ（甲基乙基酮）、ρ（丁醛）和ρ（乙酸乙酯）较高,分别为39.037、28.757、27.840 mg/m3;制药企业ρ（丙醛）较高,为4.791 mg/m3;汽车和家具制造企业ρ（二甲苯）较高,分别为15.209和2.081 mg/m3.④应用分歧系数法分析不同企业指纹谱之间的相似程度,分析结果显示,分歧系数在0.331~0.809之间,不同企业之间指纹谱存在较大差异.研究显示,建立恶臭污染排放源指纹谱可进行恶臭源排放特征识别,为恶臭污染溯源提供基础数据和科学依据.      

大气中重金属污染现状及来源研究

总结了近年来的研究成果,通过文献调研对中国大气中重金属污染现状、大气中重金属来源和重金属在环境中的迁移转化途径进行综述,提出为缓解重金属污染的高发态势,保护人群健康,应建立完善的环境污染防治体系,强化大气污染源颗粒物控制来减少重金属在大气环境中的暴露浓度,切断重金属在环境中的污染途径以减少大气传输和沉降,降低由大气-土壤-动植物-人体的重金属暴露健康风险.