Toxicological and biochemical responses of the earthworm Lumbricus rubellus to pyrene, a non-carcinogenic polycyclic aromatic hydrocarbon

The effects of the polycyclic aromatic hydrocarbon (PAH) pyrene on earthworms were investigated in contact and soil tests. In addition to measuring toxic effects on survival and reproduction, Ethoxyresorufin-o-deethylase (EROD) activity and catalase activity were also studied as possible biomarkers of toxic stress. The survival data indicated that LC₅₀ values were 0.0068 mg/ml for the contact test, and 283 mg/kg in the soil test. Cocoon production rate was significantly reduced compared to controls at 160, 640 and 2560 mg/kg in the soil test. No EROD activity could be detected in preliminary studies using control and exposed animals from the contact test, so this assay was not used to the soil test. Catalase activity was shown to be significantly lower at 640 mg/kg in the soil test compared to all other treatments and the control. When compared to toxicological data for other soil invertebrates, Lumbricus rubellus has an intermediate sensitivity in respects of survival and a lower sensitivity for reproductive effects, although the soil used in this study had a higher organic content than previous studies, meaning that the sensitivity of this species may be underestimated in comparison to previous published data for other soil invertebrates.     

大气颗粒物源解析技术研究进展

大气颗粒物源解析技术在环境管理中发挥着越来越重要的作用。本文从受体模型、样品的处理技术、源解析技术发展的最新趋势三方面介绍了大气颗粒物源解析技术的研究进展。     

环境和营养条件对煤油生物降解的影响

研究了南极假丝酵母（Candida antarctica)JWSH-112降解煤油烃的影响因素。利用正交试验方法，确证了最优条件为煤油14（ψ/%），NaNO32.0gL61,NaH2PO40.1gL^-1，蛋白胨2.0gL^-1，初始pH6.5，其中蛋白胨是影响JWSH－112降解煤油烃的重要因素。采用优化后的条件进行验证实验，煤油烃的生物降解率（49．2％）和细胞生长质量浓度（1.9gL^-1)均加高于正交试验中的最高生物降解率（47．9％）和细胞生长质量浓度（1.5gL^-1)。通过气相色谱定性分析发现，生物降解后煤油中的部分组份消失或含量明显降低。图6表5参13     

尼龙6纳米纤维膜富集/固相表面荧光法快速检测水体痕量多环芳烃研究

以静电纺丝法自制的尼龙6纳米纤维膜为吸附材料,建立了快速测定水体痕量多环芳烃(PAHs)的固相表面荧光光谱法(SSF)。将直径为5 cm的尼龙6纳米纤维膜作为滤膜用于抽滤菲、芘、荧蒽的水溶液,将膜自然晾干后置于可变角粉末样品池上,利用荧光分光光度计测量膜表面PAHs的三维固相表面荧光光谱特征,确定最佳激发发射波长,考察荧光强度随溶液初始质量浓度的线性变化关系。结果表明,菲、芘、荧蒽的最大激发发射荧光中心分别位于Ex/Em=255nm/368 nm、Ex/Em=340 nm/376 nm和Ex/Em=290 nm/437 nm处。当抽滤水样体积为500 m L时,菲、芘、荧蒽荧光强度与初始质量浓度之间的标准曲线分别为y=9432.4x+261.1,线性范围为5~500ng/m L;y=753480x+805.51,线性范围为0.2~10 ng/m L;y=9946.06x+603.48,线性范围为10~400 ng/m L,检出限分别为0.973 ng/m L、0.016 2 ng/m L和0.089 6 ng/m L。当质量浓度分别为100 ng/m L、10ng/m L和50 ng/m L时,7次测量的相对标准偏差(RSD)分别为7.1%、2.6%和5.1%,平均值相对误差分别为1%、2%和-0.2%。自来水低中高3个质量浓度的平均加标回收率分别为87.2%~98.2%、101%~120%、85.8%~92.3%。本方法具有简便、经济、灵敏度高等优点,适合于水体痕量PAHs的快速测定。     

基于硝酸盐缓释-功能微生物协同的污染底泥原位修复技术研究

重污染底泥原位修复常需外加大量电子受体,但大量实践表明电子受体直接投加存在作用时效短、微生物利用效率低等问题.针对该问题,开发了电子受体缓释-功能微生物协同的复合环境功能材料,并探讨了功能材料对底泥原位修复效果.结果表明:①复合功能材料〔以Ca（NO₃）₂计,下同〕仅投加5.7 g/kg时,底泥中ORP（氧化还原电位）提升了60.17%~73.96%,AVS（酸可挥发性硫化物）去除率高达90%,是其他传统原位修复材料的1倍.②相较于单独投加Ca（NO₃）₂的修复方式,复合功能材料最大可去除上覆水中33.78%的ρ（TN）,而且ρ（NH₄+-N）也降低了27.90%.③复合功能材料同时促进上覆水中TP和COD_Cr的去除,其去除率分别在78%和30%以上.④从经济成本和对环境影响的角度出发,在工程应用上宜用电子受体:固定剂:促凝剂:发泡剂:塑形剂:复合微生物菌剂:水的质量比为1:5:0.5:0.5:0.1:1:1的复合功能材料.研究显示,硝酸盐缓释-功能微生物复合材料是一种高效的重污染底泥原位修复材料,能显著提升底泥和上覆水中污染物去除效率,降低ρ（NH₄+-N）、ρ（COD_Cr）,避免上覆水体受到二次污染.      

基于动态综合评价的区域环境风险差异化管理

借鉴灾害风险管理理论,运用“纵横向拉开档次法”和“时序加权平均算子法”构建了区域环境风险动态综合评价模型,提出了“风险评价-等级分区-差异化管理”的区域环境风险管理方法,并以河南省为案例研究对象,开展河南省18个市级单元环境风险的动态综合评价和“差异化”管理研究.结果显示：（1）郑州、许昌、漯河等市综合环境风险指数最高,分别为13.79、13.46和13.28,信阳、南阳和三门峡等市综合环境风险指数最低,分别为4.15、4.16和5.01;（2）采用系统分层聚类法将河南省18个市级单元聚为5类环境风险等级区,其中,郑州、许昌、漯河等属于高风险区;焦作、濮阳、鹤壁等属于较高风险区;安阳、开封属于中风险区;平顶山、商丘、周口等市属于较低风险区;洛阳、三门峡、南阳等市属于低风险区;（3）根据河南省各市环境风险等级及主导因素的差异,遵循高、较高风险区“重点控制、优先管理”、中低风险区“逐步控制、加强防范”的原则,提出了“差异化”的风险管理方案.研究结果表明,该方法不仅可实现区域环境风险动态综合评价,识别区域环境风险主要贡献因子,而且“差异化”的风险管理方案更符合地方经济社会环境协调发展的实际需求.     

氨基脲诱导的大鼠神经行为毒性及其生化机制

为探究氨基脲（SEM）染毒对SD大鼠的神经行为毒性及其作用机制,将44只SPF级SD雄性大鼠随机分为4组：对照组,SEM低、中、高剂量组,每组11只,分别以0,7.5,15,30mg/（kg·bw）SEM的剂量连续灌胃染毒28d.染毒前后分别通过旷场实验和高架十字迷宫实验测试神经行为.采用液相色谱法测定γ-氨基丁酸（GABA）和谷氨酸（GLU）,ELISA法测定5-羟色胺（5-HT）、去甲肾上腺素（NE）、多巴胺（DA）、单胺氧化酶（MAO）以及N-甲基-D-天氡氨酸受体（NMDAR）含量.结果显示,高剂量染毒组大鼠在旷场实验中运动总距离和中央区域距离显著低于对照组（P<0.05）,各剂量组大鼠在高架十字迷宫实验中进入开臂时间百分比和进入开臂次数百分比均显著低于对照组（P<0.05或P<0.01）.与对照组相比,各染毒组大鼠脑组织中GABA含量和MAO活性均有不同程度降低,而GLU,NMDAR,5-HT,NE和DA水平均有不同程度上升.SEM诱导大鼠神经行为毒性的机制与破坏GABA和GLU的相互转化、增加NMDAR含量以及抑制MAO活性导致单胺类神经递质水平上升3个途径有关.     

西安城区路面细颗粒灰尘重金属污染水平及来源分析

为揭示高强度人类活动对城市环境质量的影响,在西安市采集文教区、居民区、公园景区和交通区这4个主要功能区道路灰尘样品,利用X-Ray荧光光谱仪测定粒径63μm的道路细颗粒灰尘中Cu、Pb、Zn、Cr、Co、V、Mn和Ni的含量,采用地积累指数法和污染载荷指数法评价细颗粒灰尘中重金属的污染水平,运用主成分分析、聚类分析等多元统计学方法识别重金属的可能来源,利用主成分分析-多元线性回归受体模型解析不同来源对道路细颗粒灰尘中重金属的贡献.结果表明,西安市道路细颗粒灰尘中Cu、Pb、Zn和Cr的含量高于陕西土壤背景值,而V、Mn、Ni和Co的含量接近或低于它们的土壤背景值.道路细颗粒灰尘中Co、Mn、Ni、V呈现未污染,Cr、Cu和Zn呈现轻度污染,而Pb为偏中度污染.综合污染评价结果显示,西安市道路细颗粒灰尘中重金属呈现轻度污染.多元统计分析结果表明,Cr、Cu、Pb和Zn显著正相关,属于同一主成分,且在聚类分析中为同一类;V、Mn、Ni和Co为同一类、同一主成分,且显著正相关.结合样品中各重金属元素的含量特征,推断出西安市道路细颗粒灰尘中的重金属主要有两种来源:Cu、Pb、Zn和Cr主要来源于交通源,而V、Co、Mn和Ni主要为自然源.交通源和自然源对西安市道路细颗粒灰尘中重金属的贡献分别为56.7%和43.3%.     

Determination of total hydrocarbon concentration in coastal waters and sediments off the east coast of Peninsular Malaysia

To determine the level of total hydrocarbon concentrations (THCs) along the eastern coastal regions of Peninsular Malaysia, samples of subsurface seawater (1 m) and surface sediments were collected from several sampling stations between June and August 1993. THCs in seawater and sediments as determined by fluorescence spectroscopy ranged from 1.4 to 21.8 µg L-1 (Seligi crude oil equivalents) and from 0.79 to 20.0 mg kg-1 (dry weight Seligi crude oil equivalents) respectively. In comparison to results obtained in similar surveys in Malaysian waters, the levels of THCs found in the present study were significantly lower indicating lower hydrocarbon contamination in the area studied.     

Receptor neurones in three heliothine moths responding to floral nd inducible plant volatiles

Summary. Some plant volatiles are produced in response to herbivory of several insect species, including heliothine larvae. In the present study of female heliothine moths, four co-located receptor neurone types were identified, of which three types responded strongest to the inducible compounds E--ocimene, E,E--farnesene and E,E-TMTT, respectively. The fourth type responded strongest to geraniol, which is a common floral volatile. The narrow tuning of each receptor neurone type was demonstrated by responses to a few structurally-related monoterpenes, sesquiterpenes, homo-terpenes and monoterpene alcohols, respectively, out of hundreds of plant constituents tested. The four neurone types showed the same relation of spike amplitudes and ranking of effective compounds in the three heliothine species; the polyphagous Heliothis virescens and Helicoverpa armigera and the oligophagous Helicoverpa assulta. The results indicate the presence of functionally similar types of plant odour-receptor neurones in the three related species, and suggest conservation or reappearance of functionally similar olfactory receptors in related species, independent of the evolution of polyphagy and oligophagy.