Acetylcholinesterase activity in the terrestrial snail Xeropicta derbentina transplanted in apple orchards with different pesticide management strategies

Apple orchards are highly manipulated crops in which large amounts of pesticides are used. Some of these pesticides lack target specificity and can cause adverse effects in non-target organisms. In order to evaluate the environmental risk of these products, the use of transplanted sentinel organisms avoids side-effects from past events and facilitate comparison of multiple sites in a short time. We released specimens of the terrestrial snail Xeropicta derbentina in each 5 of two kinds of apple orchards with either conventional or organic management strategies plus in a single abandoned orchard. After one month, individuals were retrieved in order to measure acetylcholinesterase (AChE) activity. Mean values of AChE activity were significantly reduced in all conventional apple orchards compared to the others. Results show that the measurement of biomarkers such as AChE inhibition in transplated X. derbentina could be useful in the environmental risk assessment of post-authorized pesticides.     

A review of biomarker compounds as source indicators and tracers for air pollution

An overview of the application of organic geochemistry to the analysis of organic matter on aerosol particles is presented here. This organic matter is analyzed as solvent extractable bitumen/ lipids by gas chromatography-mass spectrometry. The organic geochemical approach assesses the origin, the environmental history and the nature of secondary products of organic matter by using the data derived from specific molecular analyses. Evaluations of production and fluxes, with cross-correlations can thus be made by the application of the same separation and analytical procedures to samples from point source emissions and the ambient atmosphere. This will be illustrated here with typical examples from the ambient atmosphere (aerosol particles) and from emissions of biomass burning (smoke). Organic matter in aerosols is derived from two major sources and is admixed depending on the geographic relief of the air shed. These sources are biogenic detritus (e.g., plant wax, microbes, etc.) and anthropogenic particle emissions (e.g., oils, soot, synthetics, etc.). Both biogenic detritus and some of the anthropogenic particle emissions contain organic materials which have unique and distinguishable compound distribution patterns (C₁₄-C₄₀). Microbial and vascular plant lipids are the dominant biogenic residues and petroleum hydrocarbons, with lesser amounts of the pyrogenic polynuclear aromatic hydrocarbons (PAH) and synthetics (e.g., chlorinated compounds), are the major anthropogenic residues. Biomass combustion is another important primary source of particles injected into the global atmosphere. It contributes many trace substances which are reactants in atmospheric chemistry and soot paniculate matter with adsorbed biomarker compounds, most of which are unknown chemical structures. The injection of natural product organic compounds into smoke occurs primarily by direct volatilization/steam stripping and by thermal alteration based on combustion temperature. Although the molecular composition of organic matter in smoke particles is highly variable, the molecular tracers are generally still source specific. Retene has been utilized as a tracer for conifer smoke in urban aerosols, but is not always detectable. Dehydroabietic acid is generally more concentrated in the atmosphere from the same emission sources. Degradation products from biopolymers (e.g., levoglucosan from cellulose) are also excellent tracers. An overview of the biomarker compositions of biomass smoke types is presented here. Defining additional tracers of thermally-altered and directly-emitted natural products in smoke aids the assessment of the organic matter type and input from biomass combustion to aerosols. The precursor to product approach of compound characterization by organic geochemistry can be applied successfully to provide tracers for studying the chemistry and dispersion of ambient aerosols and smoke plumes. Presented at the 6th FECS Conference on Chemistry and the Environment, Atmospheric Chemistry and Air Pollution, August 26–28, 1998, Copenhagen.     

Characterisation of esterases as potential biomarkers of pesticide exposure in the lugworm Arenicola marina (Annelida: Polychaeta)

Here, we identify and characterise cholinesterase (ChE) and carboxylesterase (CbE) activities in the body tissues of the sediment dwelling worm Arenicola marina. Exposure to the organophosphorus pesticide azamethiphos yielded an in vitro IC50 of 5 microg l(-1) for propionylcholinesterase (PChE). PChE was significantly inhibited in vivo after a 10 day exposure to 100 microg l(-1) azamethiphos, equivalent to the recommended aquatic application rate (ANOVA; F=2.75, P=0.033). To determine sensitivity to environmental conditions, A. marina were exposed for 10 days to field collected sediments. PChE activity was significantly lower in worms exposed to sediments from an estuary classified to be at high risk from point source pollution by the UK Environment Agency (ANOVA; F=15.33, P<0.001). Whilst causality cannot be directly attributed from these latter exposures, they provide an important illustration of the potential utility of esterase activity as a biomarker of environmental quality in this ecologically relevant sentinel species.     

高效液相色谱-三重四级杆/复合线性离子阱质谱法测定饮用水中22种邻苯二甲酸酯

建立了一种同时测定饮用水中22种邻苯二甲酸酯(PAEs)的高效液相色谱-三重四级杆/复合线性离子阱质谱方法:饮用水样品经针头过滤器过滤,选用Biphenyl液相色谱柱进行分离,以含0.1%甲酸的水溶液和含0.1%甲酸的甲醇溶液为流动相,电离模式为电喷雾正离子,选用多反应监测触发增强子离子扫描模式进行检测。结果表明,22种PAEs的灵敏度良好,定量限为0.001～0.1μg/L。配制浓度为0.1～100.0μg/L的混标溶液进行进样分析,分析结果显示,22种PAEs在该范围内的线性关系良好,相关系数均大于0.995,方法的平均回收率为82.9%～108.9%,相对标准偏差为0.9%～11.2%。同时,使用增强子离子扫描谱图进行搜库匹配,定性准确性高。该方法适用于饮用水中PAEs的检测。     

废旧塑料处置地沉积物中邻苯二甲酸酯污染特征及其生态风险

为了解废旧塑料处置活动对区域水体的影响,采用气相质谱联用仪(GC-MS),对河北省某废旧塑料处置地沉积物中16种PAEs(phthalate esters,邻苯二甲酸酯)的污染特征和生态风险进行了研究. 结果表明:研究样地的w(∑₁₆PAEs)为0.527~102 μg/g, 平均值为18.9 μg/g,其中,DEHP〔邻苯二甲酸(2-乙基己基)酯〕是PAEs最主要的污染单体,平均占w(∑PAEs)的66.6%. 对该处置地的污染物源分析表明,沉积物中PAEs主要来源于废旧塑料回收利用过程中的环境排放. 沉积物中w(DEHP)(14.2 μg/g)和w(DBP)(1.41 μg/g)(DBP为邻苯二甲酸二正丁酯)均超过各自环境风险限值(ERLs),w(DIBP)(DIBP为邻苯二甲酸二异丁酯)超过了美国华盛顿州颁布的沉积物质量警戒限值(0.610 μg/g). 研究显示,沉积物中DBP对鱼类的生态风险及DEHP对藻类和鱼类的生态风险水平不可接受,应引起足够重视.      

具有LXRα活性效应物质的新型筛查方法研究

为了检测环境中潜在的LXRα效应物质.本研究以LXRα蛋白为例,利用核受体蛋白与小分子亲和结合的原理,构建了pCold-TF-LXRα重组蛋白并优化了重组蛋白的表达条件,建立了特异性捕获活性物质的方法.结果表明:诱导温度为20℃、诱导剂IPTG浓度为0.4mmol/L为重组蛋白的最佳表达条件;同时,利用LXRα激动剂T0901317 4个梯度浓度（0.25,2.5,25,250μg/L）的加标回收率实验测得线性回归曲线为y=0.83604x+0.40763,R²=0.9948,证明方法具有有效性;对比pCold-TF空载体蛋白（6.42%）和重组蛋白（79.83%）对T0901317（250μg/L）的回收率,说明方法具有特异性.为了验证方法的实用性,将重组蛋白与15种典型的有机磷酸酯类化合物（OPEs）的混合标样进行\"捕获\"实验,证明了TPHP、BPADP、TCrP、EHDPP、TNBP、RDP、TEHP、TDCIPP具有LXRα的活性效应.最后,用酵母双杂交实验验证了这8种OPEs均为LXRα的拮抗剂.     

高效液相色谱法测定水中的六种邻苯二甲酸酯研究

建立了高效液相色谱法测定水中六种邻苯二甲酸酯(邻苯二甲酸二甲酯、邻笨二甲酸二乙酯、邻苯二甲酸二丁酯、邻苯二甲酸二(2-乙基己基)酯、邻苯二甲酸二辛酯、邻苯二甲酸丁基苄酯)的检测方法.对水样中邻苯二甲酸酯的萃取条件和高效液相色谱分析条件进行优化,采用正己烷二次萃取,浓缩定容后分析,以乙腈-水为流动相梯度洗脱,紫外检测波长226 nm,16 min可将六种邻苯二甲酸酯分离出.方法的检出限为0.13μg/L ～0.37 μg/L,加标回收率为78.6％～118.5％,相对标准偏差为0.82％～2.17％,是一种理想的测定水中六种邻苯二甲酸酯的方法.     

高能辐射去除饮用水中邻苯二甲酸酯的影响因素

为提高高能辐射去除邻苯二甲酸脂类化合物(PAEs)的能效,研究了辐射去除的主要影响因素:剂量、射线类型、初始浓度、气氛、pH值、共存物质以及PAE类型(邻苯二甲酸二甲酯,DMP;邻苯二甲酸二乙酯,DEP;邻苯二甲酸二丁酯,DBP).以DMP为研究对象,辐照功效(GD)随PAEs初始浓度增加而增加,但随吸收剂量的增加而下降;辐照存在剂量率效应,在同等剂量下,g 辐照比EB辐照能量利用率更高.不同气氛条件下辐照降解效率顺序为:充O2>饱和空气>充N2;在本试验浓度下,辐射降解的最适初始 pH值是5~10,较低或较高pH值都会降低去除效率;水中阴离子抑制剂存在会降低去除效果.不同类型PAEs辐照去除效率大小依次为DMP,DEP,DBP.     

瓶装水中微塑料与邻苯二甲酸酯的含量及健康风险

为研究瓶装水中微塑料（MPs）和邻苯二甲酸酯（PAEs）的含量及健康风险.采用玫瑰孟加拉红染色法-立体显微镜对MPs进行定量分析,使用气相色谱串联三重四极杆质谱（GC-MS/MS）对7种PAEs进行定性及定量检测,对MPs日摄入量进行了估计,并运用健康风险评价模型对PAEs的致癌风险和非致癌风险进行了评价.结果表明,21种瓶装水中MPs丰度为48 ~216 n·L^-1（中位数为88 n·L^-1）;MPs形状大部分（72.1%）呈纤维状,碎片状仅占27.9%;小尺寸（10~50 μm）MPs的平均占比为33.9%,大尺寸MPs（>500 μm）的平均占比为4.3%;大部分MPs为蓝色. 21种瓶装水中ρ(∑PAEs)为1.15~2.47 μg·L^-1（平均值为1.62 μg·L^-1）,其中邻苯二甲酸二甲酯（DMP）、邻苯二甲酸二乙酯（DEP）、邻苯二甲酸二异丁酯（DIBP）、邻苯二甲酸二丁酯（DBP）和邻苯二甲酸二（2-乙基己基）酯（DEHP）的检出率为100%,邻苯二甲酸丁酯（BBP）和邻苯二甲酸二正辛酯（DNOP）检出率较低.DBP、DEHP和DEP浓度均低于我国饮用水标准限值. 60℃ 10 d迁移条件下ρ(∑PAEs)（平均值为1.33 μg·L^-1）,其中迁移出的DBP和DEHP含量均在允许范围内.7种PAEs在瓶身、瓶盖中均被检出,瓶身中DEHP的平均添加量最高,而瓶盖中DBP最高.估计人类不同年龄段通过饮用瓶装水的MPs摄入量（EDI）为：成人2.87 n·（kg·d）^-1、儿童3.87 n·（kg·d）^-1和婴儿5.85 n·（kg·d）^-1.健康风险评价结果显示,21种瓶装水样品及迁移实验条件下DEHP的致癌风险都小于最大可接受风险水平（1×10^-6）,且PAEs的非致癌风险指数（HIs）均小于１,表明不会对人体产生非致癌风险,但婴儿、儿童的风险值高于成人.