Bioavailability and tissue distribution of Dechloranes in wild frogs (Rana limnocharis) from an e-waste recycling area in Southeast China

Dechlorane Plus(DP), a flame retardant used as an alternative to decabromodiphenylether, has been frequently detected in organisms, indicating its bioaccumulation and biomagnification potential in aquatic and terrestrial species. However, little data is available on the bioaccumulation of DP in amphibians. Dechlorane Plus and its analogs(DPs) were detected in the liver, muscle and brain tissues of wild frogs(Rana limnocharis), which were collected from an e-waste recycling site, Southeast China. DP, Mirex, Dec 602 and a dechlorinated compound of DP(anti-Cl11-DP) varied in the range of 2.01–291, 0.650–179, 0.260–12.4, and not detected(nd)–8.67 ng/g lipid weight, respectively. No difference of tissue distribution was found for syn-DP, Mirex and Dec 602 between the liver and muscle tissue(liver/muscle concentration ratio close to 1, p 0.05). However, higher retention was observed for anti-DP and anti-Cl11-DP in the frog muscle relative to the liver tissue(liver/muscle concentration ratio 1, p 0.05). Additionally, the blood-brain barrier was found to work efficiently to suppress these compounds entering brain tissues in this species(liver/brain concentration ratio 1, p 0.05), and the molecular weight was a key factor impacting the extent of the blood-brain barrier. Compared to levels in the muscle and brain tissue, a preferential enrichment of syn-DP was observed in the liver tissue, suggesting the occurrence of stereo-selective bioaccumulation in the wild frog.     

有机磷阻燃剂甲状腺干扰效应及其作用机制研究——以磷酸三(2-氯丙基)酯(TCPP)为例

以典型有机磷阻燃剂磷酸三（2-氯丙基）酯（TCPP）为研究对象,应用GH3细胞增殖实验检测TCPP对甲状腺激素的干扰效应;应用重组甲状腺激素受体（TR）基因酵母实验和GH3（TRβ-）细胞增殖实验结合实时定量PCR技术初步探究TCPP甲状腺激素干扰作用机理.结果表明,TCPP在1×10^-4mol/L和2×10^-4mol/L浓度下对甲状腺激素T3诱导的GH3细胞增殖产生抑制效应;重组TR基因酵母实验和GH3（TRβ-）细胞增殖实验测试结果表明TCPP可能通过TR介导的基因组途径和非基因组途径诱导甲状腺激素干扰效应;实时定量PCR测试结果表明TCPP下调相关基因如：c-fos、TRβ、integrin-av和k-ras的mRNA表达,初步认为TCPP可能通过影响TRβ基因表达和激活α_vβ₃-ERK-1/2信号通路产生甲状腺激素干扰效应.     

改进型重组基因酵母TR-GRIP1检测化合物甲状腺激素干扰活性

应用酵母双杂交技术构建重组TR(甲状腺激素受体)基因酵母,用以检测类/抗甲状腺激素化合物及环境样品的甲状腺激素干扰活性. 提取并纯化含有TR基因的酵母表达质粒pGBT9-TR以及含有TR共激活因子GRIP1基因的酵母表达质粒pGAD424-GRIP1,将pGBT9-TR和pGAD424-GRIP1同时转化至酵母细胞Y187,以营养缺陷型培养基(SD/-Trp/-Leu)筛选阳性菌落,构建TR-GRIP1双杂交酵母. 考察该酵母与天然甲状腺激素——T₃(三碘甲状腺原氨酸)的结合情况,确定最佳暴露时间,建立剂量－效应关系曲线. 结果表明:TR-GRIP1双杂交酵母能够与T₃结合诱导β-半乳糖苷酶活性,选择暴露时间为2 h,T₃诱导酶活性的EC₅₀值为1.1×10-7 mol/L;构建的重组基因酵母TR-GRIP1提供了检测化合物甲状腺激素干扰活性的新方法.      

环境中新兴有机污染物得克隆的研究进展

得克隆(Dechlorane plus,DP),即双(六氯环戊二烯)环辛烷,是一种有机氯系脂肪族添加型阻燃剂,也是环境中一类新型的有机污染物。前期对环境中DP的研究主要集中在北美五大湖地区,近来我国和欧洲部分国家也开展了类似的研究。文章综述了DP各种环境介质中的浓度分布和同系物特征,并对需要重点开展的研究方向进行了展望。     

Molecular characterization and developmental expression patterns of thyroid hormone receptors (TRs) and their responsiveness to TR agonist and antagonist in Rana nigromaculata

Considering some advantages of Rana nigromaculata as an experimental species, we propose that this species, like Xenopus laevis, could be used to assay thyroid hormone（TH） signaling disrupting actions. To validate the utilizability of R. nigromaculata, we investigated the responsiveness of R. nigromaculata to a TH receptor（TR） agonist（T3） and antagonist（amiodarone） by analyzing expression, based on characterizing TR cDNA and developmental expression patterns. With high levels of identity with the corresponding genes in X. laevis, both TRα and TRβ in R. nigromaculata exhibited roughly similar developmental expression patterns to those of X. laevis, in spite of some species-specific differences. Both TRα and TRβ expression had greater changes in the liver and intestine than in the tail and brain during metamorphosis. T3 exposure for 2 days induced more dramatic increases of TRβ expression in stage 27 than in stage34 tadpoles but not in stage 42 tadpoles, showing that the responsiveness of R. nigromaculata to TH decreased with development and disappeared at the onset of metamorphic climax.Corresponding to greater changes of TRβ expression in the liver and intestine than in the tail and brain during metamorphosis, the liver and intestine had higher responsiveness to exogenous T3 than the tail and brain. Amiodarone inhibited T3-induced TRβ expression. Our results show that R. nigromaculata can be used as a model species for assaying TH signaling disrupting actions by analyzing TRβ expression, and intestine tissues at stage 27 are ideal test materials due to high responsiveness and easy accessibility.     

典型电子废物处置场地表层土壤中的德克隆阻燃剂研究

以我国广东省汕头市贵屿镇典型电子废物处置场地为研究区域,对其表层土中的德克隆(DP)阻燃剂的污染水平及分布模式进行了研究.结果表明,DP在全部23个表层土样品中均被检出,浓度范围为0.308~209ng/g,东南部地区的污染水平显著高于西北部地区,各区域的污染水平也存在一定差异.DP浓度最高点(209ng/g)和次高点(46.2ng/g)均位于主要从事电子废物手工拆解及物理破碎的片区.表层土样品中anti-DP质量分数(fanti)的变化范围为0.444~0.754 (平均值:0.652±0.064),同DP工业品中的fanti值(0.65)不存在显著性差异,表明在表层土中不存在明显的异构体选择性降解.不同的电子废物处置方式对各片区表层土中DP的分布模式影响不明显.     

In vitro fluorescence displacement investigation of thyroxine transport disruption by bisphenol A

Bisphenol A (BPA) is a chemical with high production volume and wide applications in many industries. Although BPA is known as an endocrine disruptor, its toxic mechanisms have not been fully characterized. Due to its structural similarity to thyroid hormones thyroxine (T4) and triiodothyronine (T3), one possible mechanism of BPA toxicity is disruption of hormone transport by competitive binding with the transport proteins. In this study, the binding interactions of BPA, T4, and T3 with three thyroid hormone transport proteins, human serum albumin (HSA), transthyretin (TTR), and thyroxine-binding globulin (TBG) were investigated by fluorescence measurement. Using two site-specific fluorescence probes dansylamide and dansyl-L-proline, the binding constants of BPA with HSA at drug site I and site II were determined as 2.90 104 and 3.14 104 L/mol, respectively. By monitoring the intrinsic fluorescence of tryptophan, a binding constant of 4.70 103 L/mol was obtained. Similarly, by employing 8-anilino-1-naphthalenesulfonic acid as fluorescence probe, the binding a nity of BPA with TTR and TBG was measured to be 3.10 105 and 5.90 105 L/mol, respectively. In general, BPA showed lower binding a nity with the proteins than T3 did, and even lower a nity than T4. Using these binding constants, the amount of BPA which would bind to the transport proteins in human plasma was estimated. These results suggest that the concentrations of BPA commonly found in human plasma are probably not high enough to interfere with T4 transport.     

In vitro thyroid disrupting e ects of organic extracts from WWTPs in Beijing

It is generally known that there are many endocrine disrupting compounds (EDCs) in the e uents from wastewater treatment plants (WWTPs). Most research has focused on the occurrence of estrogenic or androgenic activities, while ignoring that there are environmental chemicals disrupting thyroid system, which is essential for growth and development in both humans and animals. In the present work, a two-hybrid yeast assay was conducted to evaluate the removal e ciencies of agonistic or antagonistic thyroid receptor (TR) mediated e ects in di erent treatment processes of three WWTPs located in Beijing. We found no TR agonistic, but TR antagonistic activities in all processes from the WWTPs. The TR antagonistic activities in organic extracts of water samples were then calibrated regarding to a known TR-inhibitor, amiodarone hydrochloride (AH). The observed concentration of TR disrupting substances ranged from 2.35 10??8 to 6.19 10??7 mol/L AH in Gaobeidian WWTP, 3.76 10??8 to 8.75 10??8 mol/L AH in Lugouqiao WWTP, and 4.80 10??9 to 2.55 10??8 mol/L AH in Beixiaohe WWTP. Of the three WWTPs, the removal rates were 92.7%, 42.2%, and 23.1% respectively. Industrial sewage may contain more TR disrupting substances compared with domestic sewage. The recipient waters were found to contain considerable concentrations of TR disrupting substances that may cause adverse e ects on the exposed organisms.     

In vitro thyroid disrupting effects of organic extracts from WWTPs in Beijing

It is generally known that there are many endocrine disrupting compounds (EDCs) in the effluents from wastewater treatment plants (WWTPs). Most research has focused on the occurrence of estrogenic or androgenic activities, while ignoring that there are environmental chemicals disrupting thyroid system, which is essential for growth and development in both humans and animals. In the present work, a two-hybrid yeast assay was conducted to evaluate the removal efficiencies of agonistic or antagonistic thyroid receptor (TR) mediated effects in different treatment processes of three WWTPs located in Beijing. We found no TR agonistic, but TR antagonistic activities in all processes from the WWTPs. The TR antagonistic activities in organic extracts of water samples were then calibrated regarding to a known TR-inhibitor, amiodarone hydrochloride (AH). The observed concentration of TR disrupting substances ranged from 2.35 × 10-8 to 6.19 × 10-7 mol/L AH in Gaobeidian WWTP, 3.76 × 10-s to 8.75 x 10-s mol/L AH in Lugouqiao WWTP,and 4.80 × 10-9 to 2.55 × 10-s mol/L AH in Beixiaohe WWTP. Of the three WWTPs, the removal rates were 92.7%, 42.2%, and 23.1% respectively. Industrial sewage may contain more TR disrupting substances compared with domestic sewage. The recipient waters were found to contain considerable concentrations of TR disrupting substances that may cause adverse effects on the exposed organisms.     

江苏省淮安市大气中德克隆浓度水平及时空分布特征

为评估淮安市大气中DP（德克隆）的水平及分布特征,于2016—2018年采用大气被动采样方法,共收集了96个大气样品,对大气中ρ（DP）、ρ（syn-DP）（syn-DP为顺式DP）和ρ（anti-DP）（anti-DP为反式DP）进行分析,结合f_syn〔ρ（syn-DP）占ρ（DP）的比例〕分布模式,追溯大气中DP的迁移转化规律.结果表明:①所有样品中均检出DP,厂界内大气中ρ（DP）范围为1 925~4 221 pg/m3,平均值为3 053 pg/m3;除厂界内采样点外,其他采样点大气中ρ（DP）范围为9~92 pg/m3,平均值为42 pg/m3.②ρ（DP）最高值出现在厂界内采样点,其ρ（DP）比厂界外采样点高约3个数量级.③大气中ρ（DP）分布受季节性影响较为明显,呈冬季高、夏季低的特征.④厂界内采样点f_syn平均值为0.26,厂界外采样点的f_syn值在0.18~0.53之间,平均值为0.28,与厂界内采样点大气中DP的f_syn平均值相当.研究显示,淮安市大气中的高水平DP主要来源于DP生产,f_syn值受季节和空间变化的影响.      

沂蒙山区典型小流域降雨径流的磷素输出特征

以沂蒙山区孟良崮小流域为研究对象,通过监测2010年自然降雨条件下流域出口污染物的流失状况,选取降雨量>2mm的10场降雨,分析降雨径流特征对磷素流失的影响.结果表明,次降雨径流中总磷(TP)、颗粒态全磷(PP)、水溶性全磷(DP)、水溶性无机磷(DIP)浓度变化与流量变化过程不一致,浓度峰值均出现于流量峰值之前,而磷素通量与流量变化过程较为一致,且两者呈较好的线性关系;次降雨径流TP、PP、DP、DIP的浓度最大值及平均浓度(EMCs)差异均较大,其主要受降雨量、最大雨强和平均雨强影响,与降雨历时无显著相关关系,而浓度最小值差异较小;TP以PP流失为主,DP以DIP流失为主,DIP/DP的动态变化与降雨历时、降雨量、最大雨强和平均雨强均无显著相关关系,而PP/TP的动态变化与最大雨强显著相关.DIP、DP、TP的输出受地表径流(DR)和基流(BF)的影响较大,DIP/DP的动态变化及DIP、DP、TP的EMCs与DR/TR(地表径流/总径流量)存在多项式关系,而PP/TP的动态变化和PP的EMCs受DR/TR影响较小.     

四溴双酚-A和五溴酚对红鲫甲状腺激素和脱碘酶的影响

将红鲫(Carassius auratus)分别暴露于0.5mg·L-1四滇双酚-A(TBBPA)和0.1 mg·L-1五澳酚(PBP)中28 d,采用放射性免疫分析法和化学发光酶联免疫分析法检测红鲫的血清甲状腺激素水平和肝脏脱碘酶活性.结果显示,TBBPA能使红鲫血清TT4和TT3水平降低,rT3水平、肝脏脱碘酶ID2和ID3活性升高.PBP对红鲫甲状腺系统的干扰要小于TBBPA,它对红鲫血清TT3水平和ID2活性几乎没有影响.上述结果表明,TBBPA和PBP能够干扰红鲫体内甲状腺激素的稳态,加速甲状腺激素在肝脏内的转化和代谢;这可能是通过抑制甲状腺激素与运载蛋白的结合来实现的.     

北京官厅水库水体甲状腺激素干扰效应检测及特征

应用重组人甲状腺激素受体(hTR)基因酵母快速测试方法,检测北京官厅水库水体类/抗甲状腺激素干扰效应,并分析其地理分布、季节分布特征以及水体甲状腺激素干扰化合物(TDCs)组成特征.结果表明:官厅水库水体检出了显著的抗甲状腺激素干扰效应,与其它研究区域相比,效应处于较低到中等水平;入库河流对库区水质产生显著影响,且入库河流水质受季节影响显著,因此,库区水体不同季节甲状腺激素干扰水平存在差异;C18固相萃取柱对抗甲状腺激素干扰效应的去除率在61.9%~92.3%,表明官厅水库水体中的甲状腺激素抑制活性物质多集中在有机组分,加入30mg/L的EDTA后TR抑制活性显著降低,表明官厅水库水体中TDCs除有机化合物外可能还包含重金属类无机化合物.     

六溴环十二烷转甲状腺素蛋白结合活性及其发育期暴露的甲状腺激素干扰效应研究

为了探讨新型溴代阻燃剂六溴环十二烷(HBCDs)的潜在健康危害,采用体外研究与动物暴露实验相结合的方法,分析了HBCDs与转甲状腺素蛋白(TTR)的结合活性,以及不同剂量HBCDs暴露对发育期大鼠体内甲状腺激素水平的干扰作用.TTR竞争结合实验显示,HBCDs与125 I-T4竞争结合TTR的能力随溶液浓度的增加而升高,但即使在80μmol.L-1的高浓度下,125I-T4与TTR的结合率仍高达75.08%,表明HBCDs抑制甲状腺激素T4与转运蛋白结合的能力较弱.动物实验结果表明,新生3 d大鼠暴露于0.2 mg/kg及1 mg/kg剂量的HBCDs 21 d后,与对照组相比,暴露组大鼠血清中总三碘甲状腺原氨酸TT3、游离三碘甲状腺原氨酸FT3的含量显著升高(p0.05、p0.05);总甲状腺激素TT4、游离甲状腺激素FT4含量下降约20%,促甲状腺激素水平上升30%～230%,但3个指标变化均不具统计学意义.结合体内实验及动物实验结果,HBCDs可能通过对甲状腺激素T3的协同或替代作用产生直接和间接的甲状腺干扰效应.低剂量的HBCDs暴露即可导致发育期大鼠甲状腺激素内稳态失衡,对HBCDs发育期暴露的毒性作用值得关注.     

溴氰菊酯对稀有鮈鲫早期生命阶段发育和内分泌干扰毒性

采用半静态水体暴露方式研究了水中溴氰菊酯对稀有鮈鲫早期生命阶段的发育毒性与内分泌干扰效应.结果表明,影响稀有鮈鲫胚胎孵化的LOEC (最低可观察效应浓度)>3.0μg/L;影响稀有鮈鲫仔鱼发育畸形和死亡指标的LOEC和NOEC (无可观察效应浓度)分别为1.0和0.33μg/L.低至0.04μg/L的溴氰菊酯暴露便可显著下调稀有鮈鲫幼鱼体内雄激素受体基因(AR)表达量并上调甲状腺激素受体基因(TRβ)表达量;0.11μg/L的溴氰菊酯暴露可以下调稀有鮈鲫幼鱼体内雄激素受体基因(AR)、雌激素受体基因(ER1、ER2b)和芳香烃受体基因(AhR1a)的表达量,并上调甲状腺激素受体基因(TRβ)表达量;0.33μg/L的溴氰菊酯可以下调稀有鮈鲫幼鱼体内雄激素受体基因(AR)、雌激素受体基因(ER1、ER2b)、芳香烃受体基因(AhR1a、AhR1b、AhR2)的表达量,并诱导甲状腺激素受体基因(TRβ)表达量的上调.上述作用浓度水平已经处于多个天然水体中溴氰菊酯的检出浓度范围,因此,关于水体残留溴氰菊酯对鱼类的内分泌干扰效应必须予以重视.     

废弃电子垃圾拆解地野生鱼类卤系阻燃剂残留

为了解废弃拆解地环境中电子垃圾相关污染物的含量水平及其生态风险,本文测试了华南某废弃电子垃圾拆解地野生鲮鱼和鲫鱼体内多溴联苯醚（PBDEs）、多溴联苯（PBBs）、得克隆（DP）和替代型溴系阻燃剂（ABFRs）等卤系阻燃剂（HFRs）的含量和组成,评估了这些污染物对于野生鱼类及食鱼野生动物的生态风险.电子垃圾拆解地鲮鱼和鲫鱼体内∑HFRs的含量范围分别为1230~1680和141~650ng/g,高于对照区1~2个数量级,表明虽然粗犷的电子垃圾回收活动已禁止多年,当地野生鱼类仍然受到HFRs严重污染.PBDEs是鱼体内最主要的HFRs,鲮鱼和鲫鱼体内其分别占∑HFRs的96%和89%.鲮鱼和鲫鱼体内HFRs含量和组成均存在显著差异,可能与其生活习性、营养级和脂肪含量不同有关.风险评估结果显示,PBDEs对野生鱼类及食鱼野生动物均具有较大的生态风险.     

不同水肥管理对太湖流域稻田磷素径流和渗漏损失的影响

于2010和2011年在太湖流域开展了为期2年的田间定位试验,对2种灌溉模式(常规连续淹灌与干湿交替节灌)和4种施肥管理(不施氮、常规尿素、控释BB肥与树脂包膜尿素)条件下稻田田面水和渗漏水总磷(TP)、溶解态磷(DP)和颗粒态磷(PP)浓度的动态变化及磷素径流和渗漏损失进行了研究.结果表明:田面水TP和DP浓度变化趋势相同,均在施肥后1 d达到最高值,之后急剧下降;渗漏水TP和DP浓度变化趋势也相同,均在施肥后7 d达到最高值,然后逐渐下降.PP是田面水磷素的主要形态,DP是渗漏水磷素的主要形态.节灌降低了田面水和渗漏水磷浓度但对DP/TP影响不大,同时降低了TP径流流失量(24.7%~57.4%)和渗漏淋失量(21.0%~25.3%).施氮增加了田面水和渗漏水的磷浓度,也导致了更高的TP径流和渗漏损失.与常规尿素相比,控释BB肥提高了田面水和渗漏水的磷浓度及TP损失量,而树脂包膜尿素降低了田面水和渗漏水的磷浓度和TP损失量.综上,干湿交替节灌结合树脂包膜尿素施用能有效降低稻田磷素径流和渗漏损失,削减农业面源污染.     

巢湖流域氮磷面源污染与水华空间分布遥感解析

基于遥感监测手段,分别应用DPeRS模型和MODIS水华提取方法对巢湖流域氮磷面源污染特征和巢湖水体水华爆发规律进行遥感像元尺度解析,结果表明: 2010年巢湖流域总氮产生量为1900.3t,入河量为846.5t;总磷为244.1t,入河量为76t.巢湖流域农业面源污染对氮素污染贡献最大,而水土流失则对磷面源污染贡献最大;综合巢湖流域氮磷面源污染和水华爆发的时空特征分析,明确氮磷面源污染与巢湖水华具有相关性,并且时间上水华爆发频率较氮磷面源污染具有先滞后后同步的特征,且面源污染负荷与水华爆发面积的相关系数为0.45;在空间上,面源污染负荷较大区域与水华爆发频度较高区域也有较好的匹配性;基于这种相关性,应用DPeRS模型对巢湖流域进行氮磷减排情景分析,结果表明在施肥量减少30%,农村生活垃圾处理率提高到60%,畜禽粪便处理率和城市垃圾处理率提高到80%的情况下,氮磷面源污染平均削减率可以达到50%.     

横坡与顺坡垄作径流氮磷输出及其富营养化风险对比研究

以沂蒙山区典型的坡耕地为例,通过2种雨强(40 mm·h-1和70 mm·h-1)下的野外原位模拟降雨试验,分析了横坡与顺坡垄作地表径流溶解态无机氮Inorganic-N(NO3--N、NH4+-N)以及溶解态磷(DP)的输出特征,并利用Inorganic-N/DP、NO3--N/DP和NH4+-N/DP等3种氮磷比对...     

Profile and removal of endocrine disrupting chemicals by using an ER/AR competitive ligand binding assay and chemical analyses

An estrogen receptor (ER)/androgen receptor (AR) ligand competitive binding assay (ER/AR-binding assay) and chemical analyses were used to evaluate the endocrine disrupting chemicals (EDCs) behavior of two municipal wastewater treatment plants (WWTPs) (K and S). In the influents, estrone (E1), androsterone (A), androstenedione (AD), BPA (bisphenol A), NP (nonylphenol) and daidzein (DZ) were detected in high amounts with subsequent 24 h-average concentrations of 350, 1000, 29, 1300, 3900, and 5700 ng/L in K-WWTP and of 310, 620, 59, 1600, 2600, and 8400 ng/L in S-WWTP. The estrogenic (androgenic) activity as 17 -estradiol (E2) equivalents (EEQ) or testosterone (Te) equivalents (TEQ) was consequently 620 ng E2/L (570 ng Te/L) and 580 ng E2/L (800 ng Te/L) for the two WWTPs. The removal e ciencies of the above mentioned sole target chemicals were 51%–100% for K-WWTP and 55.6%–100% for S-WWTP. The removal e ciencies of EEQ were about 73% for both WWTPs, while the removal e ciencies of TEQ were 62.1% for K-WWTP and 98.4% for S-WWTP. In addition, chemical-derived EEQ were about 1.2%–52.4% of those by ER-binding assay for K-WWTP and the corresponding ratios were 1.3%–83.3% for S-WWTP, while chemical derived TEQ were less than 3% of values measured by the AR-binding assay for both WWTPs.