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...     

Effects of ultrasonic treatment on dithiothreitol (DTT) assay measurements for carbon materials

The dithiothreitol (DTT) assay is the most commonly used method to quantify the oxidative potential of fine particles. However, the reported DTT decay rates of carbon black (CB) materials vary greatly among different researchers. This might have resulted from either the intrinsic toxicity of CB or the unsuitability of the DTT assay protocol for CB particles. In the current study, the protocol of the DTT assay for CB materials has been carefully evaluated. It was found that the dispersion degree of CB particles in water has a great influence on the DTT decay rate of CB materials. For CB particles (special black 4A (SB4A) and Printex U) and single-walled carbon nanotube tube (SWCNT), the DTT decay rate after sonication for 10?min became 4.2, 4.6 and 1.7 times higher than that without sonication. The rate continued to grow as a function of ultrasound time up to 30?min of sonication. Although the concentration of soluble transition metals and surface oxygen-containing species such as carbonyls increased slightly with sonication, they had no significant effects on the measured DTT activity, while the increase in the dispersion degree of aggregates was found to play a vital role in the observed enhancement of the DTT decay rates for different CB materials. Based on our results, 30?min of sonication is recommended for sample dispersion when measuring the DTT decay rate of CB materials.     

Accumulation and elimination of iron oxide nanomaterials in zebrafish (Danio rerio) upon chronic aqueous exposure

A 52-day continuous semi-static waterborne exposure (test media renewed daily) regimen was employed to investigate the accumulation and elimination profiles of two iron oxide nanomaterials (nano-Fe₂O₃ and nano-Fe₃O₄) in zebrafish (Danio rerio). Adult zebrafish were exposed to nanomaterial suspensions with initial concentrations of 4.0 and 10.0 mg/L for 28 days and then were moved to clean water for 24 days to perform the elimination experiment. Fe content was measured in fish body and feces to provide data on accumulation and elimination of the two iron oxide nanomaterials in zebrafish. The experiment revealed that: (1) high accumulation of nano-Fe₂O₃ and nano-Fe₃O₄ were found in zebrafish, with maximum Fe contents, respectively, of 1.32 and 1.25 mg/g for 4.0 mg/L treatment groups and 1.15 and 0.90 mg/g for 10.0 mg/L treatment groups; (2) accumulated nanoparticles in zebrafish can be eliminated efficiently (the decrease of body burden of Fe conforms to a first-order decay equation) when fish were moved to nanoparticle-free water, and the elimination rates ranged from 86% to 100% by 24 days post-exposure; and (3) according to analysis of Fe content in fish excrement in the elimination phase, iron oxide nanomaterials may be adsorbed via the gastrointestinal tract, and stored for more than 12 days.     

人工纳米材料的生物效应及其对生态环境的影响

人工纳米材料由于具有独特的物理化学性质而得到广泛的应用,其对人体健康及环境的潜在影响也已引起科学界及政府部门的关注.通过总结近年来的相关研究资料,分类归纳了目前国内外对一些常见的人工纳米材料如富勒烯、碳纳米管、量子点、二氧化钛、纳米铁材料及纳米铝材料的生物和生态效应研究,详细总结了纳米材料毒理学的研究对象、研究方法以及最新研究成果,同时分析了各种纳米材料生物毒性的可能机制,最后对纳米材料安全性今后的研究方向进行了展望.     

Inorganic nanoparticles enhance the production of reactive oxygen species (ROS) during the autoxidation of L-3,4-dihydroxyphenylalanine (L-dopa)

Public concerns over the toxicity of nanoparticles (NPs) are growing due to the rapid development of nanotechnology. An important mechanism of nanotoxicity is oxidative stress resulting from reactive oxygen species (ROS). In this study, the chemical production of ROS by inorganic NPs oxidizing the mammalian phenolic compound, l-3,4-dihydroxyphenylalanine (l-dopa) was evaluated using a ROS sensitive dye, 2′,7′-diclorodihydrofluorescin (DCFH). CeO₂, Fe₂O₃ and Fe⁰ NPs enhanced ROS production during the autoxidation of l-dopa by more than four-fold in reactions that were dependent on O₂. This is the first report of chemical ROS production due to interaction of phenolic compounds with NPs. Mn₂O₃ oxidized DCFH in a reaction that did not require O₂ or l-dopa, suggesting a direct redox reaction between the Mn₂O₃ and the dye. CeO₂, Mn₂O₃ and to a lesser extent Fe⁰ formed clear electron paramagnetic resonance (EPR) signature for hydroxyl radicals when incubated in aerobic aqueous suspensions with spin traps. The results indicate that NPs can generate ROS via chemical reactions with medium components and biomolecules susceptible to oxidation, such as l-dopa. NPs were reactive whereas micron-sized particles were not. The combined assay with l-dopa and DCFH is a method proposed to screen for chemical ROS production by NPs.     

非常规快速电沉积制备纳米材料的方法和原理

非常规电沉积利用镀液的流动,能极大地提高电沉积速度,因而利用非常规电沉积技术制备纳米晶材料具有较好的发展和应用前景.介绍了电刷镀、流镀、喷射电沉积、摩擦喷射电沉积等几种常见的非常规电沉积的方法和原理,指出了各种方法的优缺点,展望了非常规快速电沉积技术的应用前景.     

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。     

纳米技术在环境污染防治中的应用

从大气污染控制与水污染控制等方面综述了纳米技术的研究及应用进展,并展望了纳米技术的发展前景。     

工作场所超细颗粒物暴露评估与风险评估研究进展

纳米技术产业的快速发展促使纳米材料需求量不断增长,纳米材料的规模化生产及使用,增加了暴露于超细颗粒物的职业人群数量,且工种复杂多样,尤其在自动化程度低、工人职业卫生防护意识薄弱的作业场所,对接触者有潜在的职业暴露风险.从现场暴露评估策略、检测方法、接触限值以及风险评估手段,综述针对超细颗粒物这一新型职业危害因素的研究进...     

零维碳基纳米材料细胞毒性效应的研究进展

介绍了碳基纳米材料进入细胞的主要途径,重点总结分析了几种常见零维碳基纳米材料导致细胞发生不同形式的死亡效应及其可能的毒作用机制,影响纳米材料毒性的各种理化性质也有所阐述.最后在本课题研究成果的基础上对未来碳基纳米材料的毒性研究前景进行了思考和展望,将为碳基纳米材料设计优化和广泛应用提供有价值的参考.