3种有机磷农药对水生生物的乙酰胆碱酯酶抑制效应的物种敏感度分析初探

通过筛选敌敌畏、马拉硫磷和对硫磷3种有机磷农药对水生生物的急性毒性数据和乙酰胆碱酯酶抑制效应数据,构建物种敏感度分布曲线进行了比较分析。结果表明,敌敌畏对水生生物的急性毒性和乙酰胆碱酯酶抑制效应的大小顺序为:酶体内抑制效应酶体外抑制效应急性毒性;马拉硫磷和对硫磷的乙酰胆碱酯酶抑制效应数据不足但趋势相似,顺序为:酶体内抑制效应急性毒性酶体外抑制效应。敌敌畏的急性毒性和酶体外抑制效应的5%危害浓度(HC5)分别为2.07μg·L~(-1)和1.53μg·L~(-1),两者相差1.4倍。在水质基准推导中,乙酰胆碱酯酶抑制效应数据对有机磷农药的水生生物基准具有重要的参考价值。     

大辽河表层水中邻苯二甲酸酯分布特征及环境健康风险评价

利用气相色谱-质谱(GC-MS)检测了大辽河表层水中邻苯二甲酸酯类(PAEs)有机污染物的浓度水平,分析其分布特征,并对PAEs类有机污染物的环境健康风险进行了评价。结果表明,大辽河表层水中共检出4种PAEs,其质量浓度范围为n.d.#0.754μg·L~(-1)。4种PAEs类中质量浓度平均值最高的为邻苯二甲酸二异辛酯(DIOP)(0.36μg·L~(-1)),最低的为邻苯二甲酸二甲酯(DMP)(0.01μg·L~(-1))。4种PAEs浓度贡献大小依次为:邻苯二甲酸二异辛酯(DIOP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二甲酯(DMP)。DBP浓度基本符合国家地表水环境质量标准(GB3838—2002)。与国内其他水域相比,大辽河表层水中PAEs的污染程度处于较低水平。DMP和DEP的最高值均出现在营口市区最主要的工业和生活污水排污口之一——纱厂潮沟采样点,DBP和DIOP的最高值则分别出现在牛庄大桥和港监潮沟采样点。总PAEs类有机污染物分布趋势为:在工业分布较多的区域及主城区附近水域PAEs浓度较高,大辽河上游区域PAEs浓度相对较低。利用US EPA健康风险评估模型粗略估算,大辽河表层水中PAEs类污染物的非致癌风险指数值低于1。     

水中微量邻苯二甲酸酯类物质实用分析方法的确定

邻苯二甲酸酯(PAEs)是危害性严重的一类持久性有害污染物。含量极微,测定难度大。通过试验对比了液液萃取、固相萃取富集技术和液相色谱、气质联机测定方法对水中微量邻苯二甲酸酯类物质的分析测定。结果表明,固相萃取-气相色谱-质谱方法是实验室条件下,水中微量邻苯二甲酸酯类物质的优化分析方法。     

固相萃取填料对水中脂肪族二元酸酯类增塑剂萃取效率的影响

以水中11种脂肪族二元酸酯类(ADEs)增塑剂的固相萃取-气相色谱-质谱法(SPE-GC-MS)为例,探讨了用C₁₈柱和HLB柱萃取水样时不同品牌、不同批号的SPE填料和C₁₈柱封端与否及相对应的洗脱溶剂不同配比对萃取效率的影响。实验结果表明:正己烷不可作为C₁₈柱和HLB柱的淋洗溶剂;11种ADEs用不同配比的二氯甲烷/正己烷溶剂体系洗脱,对C₁₈柱和HLB柱,不同SPE填料最佳二氯甲烷体积分数分别为0~60%和15%~20%;未经封端处理的C₁₈柱不适合作为ADEs的SPE柱;最佳溶剂洗脱体积为5 mL,样品穿透体积至少为200 mL;在优化条件下,11种ADEs方法检出限为0.2~0.5 μg/L,实际样品加标回收率为85.2%~113%,平行样相对标准偏差为5.5%~18%,各特性指标显示该方法正确度、精密度和灵敏度良好。     

Chlorpyrifos induces oxidative stress in rats

This study was carried out in male Wistar rats to determine the potential effects of chlorpyrifos (CHP) on oxidative stress, as was reported for organophosphorus (OP) pesticides. Following an acute, daily 3- or 14-day exposure with CHP at doses of 2.5, 5, or 25 mg kg^?1 data showed significant increases in malondialdehyde levels at both exposure durations and at all doses, except for 2.5 mg kg^?1, in hepatic and aorta, kidney, and plasma samples. The nitrites (NO) showed elevation at 25 mg kg^?1 in aorta, at 3- and 14-day exposure, in hepatic tissue with all doses at 3-day exposure, but not at 14-day with a 5 mg kg^?1 dose. In plasma, increases occurred only at 25 mg kg^?1 at both exposure times, and in kidney at all doses and both exposure durations. Superoxide dismutase (SOD) enzyme activity in the aorta sample was statistically significant at all doses at 3 days and at 14 days, except at 2.5 mg kg^?1; and in hepatic tissue only at 25 mg kg^?1 dose at both durations. In plasma SOD activity was elevated at all doses at 3 days, but at 14 days only at 25 mg kg^?1. Data suggests that oxidative stress may be involved in the effects of CHP on rats.     

Subacute chlorpyrifos-induced alterations in serum lipids and some oxidative stress biomarkers in male Wistar rats: beneficial effect of acetyl-L-carnitine

The present study evaluated the beneficial effect of acetyl-L-carnitine (ALC) on subacute chlorpyrifos (CPF)-induced alterations in serum lipid profiles and some biomarkers of oxidative stress in Wistar rats. Twenty-eight adult male rats divided into four groups of seven animals each (group I–IV) were used: I (S/oil) received soya oil (2 ml kg^?1), II (ALC) received ALC (300 mg kg^?1); III (CPF) received CPF (8.5 mg kg^?1 ～ 1/10th LD₅₀); IV (ALC+CPF) was pretreated with ALC (300 mg kg^?1) and then exposed to CPF (8.5 mg kg^?1), 30 min later. The treatment was orally for 28 days duration. Sera obtained from blood samples were evaluated for the levels of triglyceride (TG), total cholesterol (TC), high density lipoprotein-cholesterol (HDL-c), malondialdehyde (MDA), and the activities of superoxide dismutase (SOD) and catalase (CAT). The levels of low density lipoprotein-cholesterol (LDL-c), very low density lipoprotein-cholesterol (VLDL-c), and atherogenic index (AI) were calculated. The result showed that elevated levels of TG, TC, LDL-c, VLDL-c, AI, and MDA, and the decreased levels of HDL-c, CAT, and SOD induced by CPF were modulated by ALC. It was concluded that ALC ameliorated the alterations in serum lipid and oxidative stress induced by CPF exposure in the rats, partly through its antioxidant properties.     

3种PAEs对蚯蚓的毒性作用和组织酶活性影响的研究

以赤子爱胜蚓(Eisenia foetida)为受试生物,通过滤纸接触法和自然土壤法研究邻苯二甲酸二甲酯(Dimethyl Phthalate,DMP)、邻苯二甲酸二乙酯(Diethyl Phthalate,DEP)和邻苯二甲酸二正丁酯(Di-n-butyl Phthalate,DBP)的急性毒性效应.结果表明,DEP和DMP对赤子爱胜蚓毒性显著,滤纸接触法染毒48 h时,DMP和DEP的半数致死剂量(LD50)分别为129.603μg·cm-2和145.336μg·cm-2.自然土壤法染毒14 d时,DMP和DEP的LC50分别为1 560.120 mg·kg-1和1 516.186 mg·kg-1.DBP的LD50尚无确切数据.自然土壤法研究DMP、DEP与DBP对蚯蚓组织超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和乙酰胆碱酯酶(AChE)活性的影响.结果表明,SOD、CAT和AChE活性对DMP、DEP和DBP的毒性响应各不相同,其中,DMP、DEP和DBP的浓度对SOD、CAT和AChE活性呈显著性影响.SOD活性被DMP和DEP诱导增加.CAT的活性在DEP和DBP低浓度下诱导高浓度作用下抑制,而AChE活性在DEP和DBP低浓度下抑制高浓度下诱导.处理时间对SOD、AChE活性无显著性影响.     

3DBER-S-Fe同步脱氮除磷及去除邻苯二甲酸酯的工艺特性

为探究三维电极生物膜耦合硫铁新工艺(3DBER-S-Fe)脱氮除磷并同步去除邻苯二甲酸酯(PAEs)的工艺特性,在水力停留时间(HRT)分别为8、6、4 h条件下,研究分析了系统内总氮(TN)、总磷(TP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二(2-乙基)己酯(DEHP)、NO-3-N、SO2-4及pH的变化情况.结果表明,3DBER-S-Fe系统具有较好的脱氮除磷及PAEs去除效果.当水力停留时间为8、6、4 h时,TN去除率分别为80.99%、78.85%、64.76%;TP去除率分别为65.18%、67.17%、43.44%;DBP去除率分别为96.72%、97.32%、96.53%;DEHP去除率分别为91.89%、81.57%、74.30%.在3DBER-S-Fe系统内,存在异养、氢自养、硫自养反硝化脱氮过程,当HRT由8h缩短到4h时,单质硫可以弥补进水NO-3-N负荷增加所导致的反硝化电子供体相对不足问题,维持系统高效的脱氮效率;系统中海绵铁填料腐蚀产生的铁离子能够高效持续沉淀除磷;3DBER-S-Fe工艺结合了物理吸附、生物降解及电化学作用,使其在不同HRT条件下具有较高的DBP与DEHP去除率.     

邻苯二甲酸酯在三峡库区消落带非淹水期土壤中污染特征及健康风险

本研究利用超高效液相色谱飞行时间质谱(UPLC-Q-TOF~-MS)分析了三峡库区8个消落带河段土壤样品中邻苯二甲酸酯(PAEs)的浓度水平,探讨了其组成特征,通过相关性分析和主成分分析阐明了其可能的来源,并且采用健康风险模型评价了PAEs在消落带土壤中的人群健康风险.结果表明,ΣPAEs在三峡库区消落带的含量(以干重计,下同)范围为322.0~737.3 ng·g~(-1),平均值为497.2 ng·g~(-1),处于文献报道的较低水平;DIBP是丰度最高的同系物单体,其次是DBP和DEHP,三者平均贡献率为94.5%,然而DEHP并不是主要污染物,这可能由于在淹水状态下消落带土壤向水体释放DEHP,但DEHP在土壤微生物中降解也不能完全排除;DMP、DEP、DBP和DIBP两两之间具有极显著正相关性,同时结合主成分分析,表明4种PAEs可能具有相同来源.人群暴露6种PAEs的日均摄入量均未超过美国EPA规定的参考剂量(Rf D),并且6种PAEs单体的致癌风险均远低于美国EPA规定的可接受致癌风险值,但是DBP的日均摄入量占总PAEs的60%~84%,因此,在三峡库区消落带耕作过程中应预防DBP带来的潜在健康风险.     

Abiotic degradation of four phthalic acid esters in aqueous phase under natural sunlight irradiation

Abiotic degradability of four phthalic acid esters (PAEs) in the aquatic phase was evaluated over a wide pH range 5–9. The PAE solutions in glass test tubes were placed either in the dark and under the natural sunlight irradiation for evaluating the degradation rate via hydrolysis or photolysis plus hydrolysis, respectively, at ambient temperature for 140 d from autumn to winter in Osaka, Japan. The e ciency of abiotic degradation of the PAEs with relatively short alkyl chains, such as butylbenzyl phthalate (BBP) and di-nbutyl phthalate (DBP), at neutral pH was significantly lower than that in the acidic or alkaline condition. Photolysis was considered to contribute mainly to the total abiotic degradation at all pH. Neither hydrolysis nor photolysis of di-ethylhexyl phthalate (DEHP) proceeded significantly at any pH, especially hydrolysis at neutral pH was negligible. On the other hand, the degradation rate of diisononyl phthalate (DINP) catalyzed mainly by photolysis was much higher than those of the other PAEs, and was almost completely removed during the experimental period at pH 5 and 9. As a whole, according to the half-life (t1=2) obtained in the experiments, the abiotic degradability of the PAEs was in the sequence: DINP (32–140 d) > DBP (50–360 d), BBP (58–480 d) > DEHP (390–1600 d) under sunlight irradiation (via photolysis plus hydrolysis). Although the abiotic degradation rates for BBP, DBP, and DEHP are much lower than the biodegradation rates reported, the photolysis rate for DINP is comparable to its biodegradation rate in the acidic or alkaline condition.