Environmental risk assessment of selected organic chemicals based on TOC test and QSAR estimation models

Environmental risks of organic chemicals have been greatly determined by their persistence,bioaccumulation, and toxicity(PBT) and physicochemical properties. Major regulations in different countries and regions identify chemicals according to their bioconcentration factor(BCF) and octanol–water partition coefficient(Kow), which frequently displays a substantial correlation with the sediment sorption coefficient(Koc). Half-life or degradability is crucial for the persistence evaluation of chemicals. Quantitative structure activity relationship(QSAR) estimation models are indispensable for predicting environmental fate and health effects in the absence of field-or laboratory-based data. In this study, 39 chemicals of high concern were chosen for half-life testing based on total organic carbon(TOC) degradation,and two widely accepted and highly used QSAR estimation models(i.e., EPI Suite and PBT Profiler) were adopted for environmental risk evaluation. The experimental results and estimated data, as well as the two model-based results were compared, based on the water solubility, Kow, Koc, BCF and half-life. Environmental risk assessment of the selected compounds was achieved by combining experimental data and estimation models. It was concluded that both EPI Suite and PBT Profiler were fairly accurate in measuring the physicochemical properties and degradation half-lives for water, soil, and sediment.However, the half-lives between the experimental and the estimated results were still not absolutely consistent. This suggests deficiencies of the prediction models in some ways, and the necessity to combine the experimental data and predicted results for the evaluation of environmental fate and risks of pollutants.     

上海市郊销售使用农药的环境毒理评价

调查了上海市郊1994年的农药销售使用量,并对其进行了农药排毒系数和农药使用危险性的环境毒理评价。结果表明,1994年上海市郊农药总销售用量为2418.64t,总排毒系数为35.43×10~6t/a,销售使用农药的LD_(50)为68.3mg/kg,接近我国高毒农药LD_(50)的界限(50mg/kg)。农药总用量最高的是南汇县,最低的是宝山区;排毒系数最高的也是南汇县,最低的是崇明县和浦东新区。从环境毒理角度看,上海市郊销售使用农药的结构很不合理,存在高效农药比例小,农药急性毒性高,使用危险性程度较高,及水溶性农药比例较大等问题。     

环境毒理学研究进展

综述了近年来环境毒理学的研究进展,内容包括:环境污染物对机体的影响及其环境行为、环境污染物及其转化物的毒性和评估方法、实验室模式生物、生物标志物以及环境毒理学在其他相关学科中的应用等.此外,还对环境化学品管理和安全性评价、Hormesis(兴奋效应)现象、遗传毒性致癌物的危险度评价、室内环境毒理学分析与研究等热点问题进...     

NLRP3 inflammasome activation determines the fibrogenic potential of PM2.5 air pollution particles in the lung

Airborne fine particulate matter(PM_2.5) is known to cause respiratory inflammation such as chronic obstructive pulmonary disease and lung fibrosis. NLRP3 inflammasome activation has been implicated in these diseases; however, due to the complexity in PM_2.5compositions, it is difficult to differentiate the roles of the components in triggering this pathway. We collected eight real-life PM_2.5samples for a comparative analysis of their effects on NLRP3 inflammasome ...     

铜、镉对鮸鱼幼鱼鳃丝Na^＋ -K^＋ -ATPase和肝脏SOD酶活性的影响

以鮸鱼（Miichthysmiiuy）幼鱼为研究对象,研究了Cu^2＋和Cd2＋对鮸鱼幼鱼鳃丝Na^＋-K^＋-ATPase和肝脏SOD酶活性的影响。以6个Cu^2＋浓度（0.01mg/L、0.05mg/L、0.1mg/L、0.2mg/L、0.4mg/L和0.8mg/L）和6个Cd^2＋浓度（0.005mg/L、0.025mg/L、0.05mg/L、0.1mg/L、0.2mg/L、0.4mg/L）对鮸鱼幼鱼进行8d染毒。结果表明,Cu^2＋和Cd^2＋各处理组鱼鳃丝Na^＋-K^＋-ATPase活力随取样时间的变化显著（P〈0.05）,且呈峰值变化,在1d时达到最大值,然后缓慢下降,最后各处理组酶活力趋于稳定。两种重金属离子对鮸鱼鳃丝Na^＋-K^＋-ATPase活力的影响在同一取样时间各处理组间的差异也显著（P〈0.05）,其影响程度与重金属的浓度呈负相关,且Cd2＋浓度为0.4mg/L时,在第8天酶活力与对照组的差异不显著（P〉0.05）。Cu^2＋和Cd2＋在1～8d对鮸鱼鳃丝Na^＋-K^＋-ATPase活力的诱导率表现为Cu^2＋〉Cd^2＋。低浓度组Cu^2＋和Cd^2＋曝露时,鮸鱼肝组织中SOD活性变化在短时间内不明显（P〉0.05）,但随着时间的延长,SOD活性提高,与对照组差异显著（P〈0.05）,导致“毒物兴奋效应”。高浓度Cu^2＋和Cd^2＋曝露时,随着时间的延长和浓度的增强,肝组织SOD的活力抑制越明显（P〈0.05）。     

生理药代动力学模型及其在健康风险评价中的应用研究进展

生理药代动力学(Physiologically Based Pharmacokinetic,PBPK)模型在健康风险评估中的应用逐渐成为研究的焦点.简要阐述了PBPK模型的定义及发展历程,在此基础上详细介绍了PBPK模型建立的过程及其在致癌风险评估、混合物健康风险评估中的应用.最后,总结了该模型在健康风险评估应用中的受限因素,提出跨学科合作有利于解决这些受限因素,从而进一步推进该模型在混合物健康风险评价中的应用.     

金属和非金属纳米材料对四膜虫生物毒性研究

纳米材料是"21世纪最有前途的材料",以其优良的性能广泛应用于许多领域,随之以多种形式释放到环境中。目前,关于纳米材料的安全性还没有明确的论断。本文介绍了四膜虫在纳米材料生物效应研究中的优势,重点论述了金属纳米材料、非金属纳米材料对四膜虫的生物效应以及毒性机制的研究状况,并对今后纳米材料生物毒性效应研究提供了建设性的方法及意见。     

环境毒理学和生态毒理学在环境风险评价中的应用

对环境毒理学与生态毒理学的概念以及相互之间的关系进行了论述,并分析了它们与环境风险评价的相互关联,以及在环境风险评价中的应用.在此基础上指出,目前环境毒理学与生态毒理学在环境风险评价应用中存在的主要问题,并对今后的研究方向提出展望和建议.     

USING INFILTRATION ENHANCEMENT AND SOIL WATER MANAGEMENT TO REDUCE DIAZINON IN RUNOFF1

ABSTRACT: Pesticide runoff from dormant sprayed orchards is a major water quality problem in California's Central Valley. During the past several years, diazinon levels in the Sacramento and San Joaquin Rivers have exceeded water quality criteria for aquatic organisms. Orchard water management, via post‐application irrigation, and infiltration enhancement, through the use of a vegetative ground cover, are management practices that are believed to reduce pesticide loading to surface waters. Field experiments were conducted in Davis, California, to measure the effectiveness of these management practices in reducing the toxicity of storm water runoff. Treatments using a vegetative ground cover significantly reduced peak concentrations and cumulative pesticide mass in runoff for first flush experiments compared with bare soil treatments. Post‐application irrigation was found to be an effective means of reducing peak concentrations and cumulative mass in runoff from bare soil treatments, but showed no significant effect on vegetated treatments.