Effects of Turbidity,Sediment, and Polyacrylamide on Native Freshwater Mussels

Turbidity is a ubiquitous pollutant adversely affecting water quality and aquatic life in waterways globally. Anionic polyacrylamide (PAM) is widely used as an effective chemical flocculent to reduce suspended sediment (SS) and turbidity. However, no information exists on the toxicity of PAM‐flocculated sediments to imperiled, but ecologically important, freshwater mussels (Unionidae). Thus, we conducted acute (96 h) and chronic (24 day) laboratory tests with juvenile fatmucket (Lampsilis siliquoidea) and three exposure conditions (nonflocculated settled sediment, SS, and PAM‐flocculated settled sediment) over a range of turbidity levels (50, 250, 1,250, and 3,500 nephelometric turbidity units). Survival and sublethal endpoints of protein oxidation, adenosine triphosphate (ATP) production, and protein concentration were used as measures of toxicity. We found no effect of turbidity levels or exposure condition on mussel survival in acute or chronic tests. However, we found significant reductions in protein concentration, ATP production, and oxidized proteins in mussels acutely exposed to the SS condition, which required water movement to maintain sediment in suspension, indicating responses that are symptoms of physiological stress. Our results suggest anionic PAM applied to reduce SS may minimize adverse effects of short‐term turbidity exposure on juvenile freshwater mussels without eliciting additional lethal or sublethal toxicity.     

A preliminary explore to the forced ventilation on the toxic gas release/dispersion and the hazard mitigation within a petrochemical plant

More than thirty-five years ago, the Bhopal disaster shook the whole world and investigators found out that many people survived just because they turned on the fans in their bedrooms. It was postulated that the forced ventilation played an important role in diluting the toxic gas and saved these people. In order to provide evidence to solve this old mystery, this research employed FLACS software to assess the hazardous degree of a toxic gas (hydrogen sulfide) leakage within a petrochemical process. Series of gas dispersion simulations were performed to actualize the hazardous characteristics and the corresponding risks of the release accident. The study shows that the hazardous level and the hazard range can be greatly influenced when parameters, such as the gas leakage circumstances (atmospheric conditions and wind speed) and the mitigation measures (direction of fans and their speed) are altered.By using explosion-proof fans in different positions and ventilation directions, combined with the natural wind in a certain direction, this research attempts to detect the best combination from various mitigation designs and to compare the influence of fan directions on hazard mitigation. It is also the first time of its kind to simulate the effect of forced ventilation on hazard mitigation within a process plant. The results show that the hazardous level of a toxic release can be effectively alleviated, when the direction of the mechanical ventilation is against the natural wind direction. With the help of the CFD simulation and the quantitative risk analysis technique, different loss prevention strategies can be tested via this method in order to establish a safer working environment.     

一起突发性鱼塘污染事件应用水生毒理学评价的可行性研究

文章探讨了采用斑马鱼、大型水蚤急性毒性试验评价突发性水塘化学污染事件的可行性。结果表明：斑马鱼、大型水蚤急性毒性试验对水塘化学污染具有较好的敏感性,其斑马鱼24 h,48 h和96 h LC50分别为42%、30%和22.4%,大型水蚤48h、96h LC50分别为63%和17%,可以用于水塘化学污染的综合毒性评价。     

有毒物质低剂量刺激作用的研究进展

有毒物质低剂量刺激作用(hormesis)是一个有争议的毒理学问题.本文综述了hormesis的研究进展、关键学术问题以及可能的作用机制,并对有关hormesis的机理研究与环境内分泌干扰物研究和风险评价理论及方法之间的关系进行了讨论,提出了其中存在的关键科学问题和可能的研究方向.     

我国大气环境毒理学研究新进展

对大气环境中重要污染物的毒理学作用及其机制方面的文献进行综述。首先,总结了细颗粒物(PM2.5)和纳米颗粒物对呼吸系统和心血管系统毒理学作用及其机理方面的研究;然后,评述了二氧化硫(SO2)对基因表达的影响及内源性SO2生理作用方面的研究,提出SO2既是一种全身性毒物,又是一种新型信号分子的新观点;对大气环境致癌物,特别是有关苯并芘致癌作用分子机制的研究进行讨论;对大气中臭氧和光化学烟雾对健康影响的研究作了评述;最后,对室内空气污染物尤其是甲醛的毒性作用及其机理方面的最新研究进行了评论。     

大气颗粒物暴露与健康效应研究进展

大气颗粒物一直是影响我国大多数城市空气质量的首要污染物,且呈现出与欧美不同的煤烟、机动车尾气以及开放源复合型污染并存的高浓度污染态势,已有研究发现颗粒物的短期或长期暴露均会对人体产生不良的健康效应。本文从环境科学、暴露科学、环境流行病学和环境毒理学研究等方面系统综述了大气颗粒物健康效应研究的方法和进展,可为我国的大气颗粒物健康效应研究与大气颗粒物环境质量标准的修订提供方法学参考和经验借鉴。目前我国PM10污染尚未得到有效控制,细颗粒物(PM2.5)的污染也已引起关注,建议在不同区域开展空气污染健康效应的系统研究。     

溴系阻燃剂毒理效应的计算模拟预测与环境风险评估进展

溴系阻燃剂(brominated flame retardants,BFRs)作为生产和使用量巨大的有机阻燃剂,在环境介质和生物体内被广泛检出。BFRs及其代谢产物会对生物体造成神经毒性、遗传毒性、发育毒性及内分泌干扰效应等,环境和健康风险得到日益广泛的关注。国内外学者通过最小二乘法(LS)和类似马尔可夫链蒙特卡罗算法(AMCMC)等统计分析方法建立了BFRs在环境中转化和归趋的预测模型,采用分子对接、分子动力学模拟和定量结构-活性关系(QSAR)模型等方法分析了BFRs及其代谢产物毒性作用的微观机制。综合近年来国内外的相关研究,发现BFRs的结构(取代基的类型和数量)会影响其环境行为和毒理效应,在总结研究成果的基础上,对BFRs的生态和健康风险进行评估,为其未来的研究和发展方向提供参考。     

热带爪蟾(Xenopus tropicalis)胚胎在生态毒理学中的应用前景

首先介绍了热带爪蟾(Xenopus tropicalis)作为新的模式动物的发展过程以及热带爪蟾基因组学方面的研究进展,概述了非洲爪蟾(X.laevis)胚胎在生态毒理学中的应用。在此基础上,详细讨论了热带爪蟾胚胎在污染物致毒效应和作用机理、毒理学理论和环境样品生态毒性检测等方面的应用现状和前景。最后,简要介绍了目前国内外有关热带爪蟾网站、书籍和养殖等方面的信息资源。     

理论毒理学研究进展

毒理学是近代发展起来的科学,由于工农业生产的迅速发展,化学物质剧增,迄今登记在册的化学物质已超过2 600万种,每年还新增2 000多种,因此传统的毒性鉴定已远远不能满足时代的要求,针对各种化学物质的细致的毒理学研究更是难以实现。因此毒理学必须在理论层面实现突破,缩短研究时间,减少研究经费及人力、物力的消耗,同时可使化学物质得到更安全的应用。另外,动物保护已列入议事日程,不再允许大量使用动物做毒理方面的实验,这些促进了理论毒理学的发展。     

Oxidative stress in the blood of pregnant rats and reduction of organ weights caused by the polychlorinated biphenyl congener 77

3,3′,4,4′-Tetrachlorobiphenyl (PCB 77), one of the environmentally persistent polychlorinated biphenyls that have been used for industrial purposes, was repeatedly administered to pregnant rats by gavage at a dose of minimal, non-lethal toxicity in order to study its effects on routine blood variables, parameters of oxidative stress and hematopoietic organs in pregnant female rats. Of the routine blood parameters, PCB 77 reduced the mean corpuscular hemoglobin concentration and platelet counts; the levels of malondialdehyde and glutathione peroxidase in the blood were higher during the first days of gestation (1–7), as compared to the respective controls. In the subsequent period between days 8 and 18, these parameters did not show any significant change after PCB 77 treatment. Routine blood parameters and oxidative stress parameters indicated a moderate degree of oxidative stress which alone could not bring about the serious weight reduction of the thymus, pituitary, and kidneys. The extent of oxidative stress did not correlate with the weight reduction of some of the blood-forming organs.