有毒物质Hormesis效应的识别与评价

有毒物质Hormesis效应对传统的毒理学模型提出了挑战.在低剂量条件下单纯的效应增强并不一定是Hormesis效应,可能由效应的某种波动或试验误差引起.对有毒物质Hormesis效应特征、发生的低剂量范围及其识别与评价方法进行了综述,并以低剂量镉对蚯蚓体内谷胱甘肽过氧化物酶(GSH - PX)活性影响为例,建立了Hormesis效应及其定量评价方法.结果表明,二次函数拟合模型为y=0.3994- 1.4472X2+ 1.707X,刺激效应强度为45.34％.     

二亿人患职业病呼唤法律的完善

根据卫生部提供的数据,我国现有约1600万家企业存在有毒有害作业场所,约2亿劳动者在从事劳动过程中遭受不同程度职业病危害。有关职业病的案例,不时见诸媒体。北京义联劳动法援助与研究中心在全国范     

德国将中止页岩气钻探,因勘探技术或污染地下水

正据美国《华尔街日报》报道,德国计划未来七年中止页岩气钻探,原因是担心页岩气的勘探技术可能会污染地下水.据报道,页岩气的开采需要使用水力压裂技术.这种技术是用掺入水、沙子和化学物质的高压混合物将岩石层压裂,从而释放出天然气.德国政府计划禁止在离地表不到3000m的钻探作业中使用水力压裂技术,并希望在明年初制定一项法令.这一禁令将于2021年被重新评估.     

Physiological cellular responses and adaptations of Rhodococcus erythropolis IBBPo1 to toxic organic solvents

A new Gram-positive bacterium, Rhodococcus erythropolis IBBPo1（KF059972.1） was isolated from a crude oil-contaminated soil sample by enrichment culture method. R. erythropolis IBBPo1 was able to tolerate a wide range of toxic compounds, such as antibiotics（800–1000 μg/mL）,synthetic surfactants（50–200 μg/mL）, and organic solvents（40%–100%）. R. erythropolis IBBPo1 showed good tolerance to both alkanes（cyclohexane, n-hexane, n-decane） and aromatics（toluene, styrene, ethylbenzene） with logPOW（logarithm of the partition coefficient of the solvent in octanol–water mixture） values between 2.64 and 5.98. However, alkanes were less toxic for R. erythropolis IBBPo1 cells, compared with aromatics. The high organic solvent tolerance of R. erythropolis IBBPo1 could be due to the presence in their large genome of some catabolic（alkB, alkB1, todC1, todM, xylM）, transporter（HAE1） and trehalose-6-phosphate synthase（otsA1, KF059973.1） genes. Numerous and complex physiological cellular responses and adaptations involved in organic solvent tolerance were revealed in R. erythropolis IBBPo1 cells exposed 1 and 24 hr to 1% organic solvents. R. erythropolis IBBPo1 cells adapt to 1% organic solvents by changing surface hydrophobicity, morphology and their metabolic fingerprinting.Considerable modifications in otsA1 gene sequence were also observed in cells exposed to organic solvents（except ethylbenzene）.     

Effects of seasonal climatic variability on several toxic contaminants in urban lakes: Implications for the impacts of climate change

Climate change is supposed to have influences on water quality and ecosystem. However, only few studies have assessed the effect of climate change on environmental toxic contaminants in urban lakes. In this research, response of several toxic contaminants in twelve urban lakes in Beijing, China, to the seasonal variations in climatic factors was studied. Fluorides, volatile phenols, arsenic, selenium, and other water quality parameters were analyzed monthly from2009 to 2012. Multivariate statistical methods including principle component analysis, cluster analysis, and multiple regression analysis were performed to study the relationship between contaminants and climatic factors including temperature, precipitation, wind speed, and sunshine duration. Fluoride and arsenic concentrations in most urban lakes exhibited a significant positive correlation with temperature/precipitation, which is mainly caused by rainfall induced diffuse pollution. A negative correlation was observed between volatile phenols and temperature/precipitation, and this could be explained by their enhanced volatilization and biodegradation rates caused by higher temperature. Selenium did not show a significant response to climatic factor variations, which was attributed to low selenium contents in the lakes and soils. Moreover, the response degrees of contaminants to climatic variations differ among lakes with different contamination levels. On average, temperature/precipitation contributed to 8%, 15%, and 12% of the variations in volatile phenols, arsenic, and fluorides,respectively. Beijing is undergoing increased temperature and heavy rainfall frequency during the past five decades. This study suggests that water quality related to fluoride and arsenic concentrations of most urban lakes in Beijing is becoming worse under this climate change trend.     

对环境监测实验室常见废液的处理探讨

环境监测实验室在日常工作中常常需要使用化学试剂,尤其是剧毒、致癌的废液在排放中需要进行有效的处理,以防范对环境和人体的危害。如某些掩蔽剂、萃取剂等的使用,很容易对环境造成二次污染。因此,本文将从环境监测实验室废液处理方法上展开探讨,并提出积极的应对策略。     

有限空间作业常见隐患(二)

有限空间是指封闭或者部分封闭,与外界相对隔离,人员进出受限但可以进入、未被设计为固定的工作场所,作业人员不能长时间在内工作,自然通风不良,易造成有毒有害、易燃易爆物质积聚或者氧含量不足,或存在淹溺、坍塌掩埋、触电、机械伤害等其他危险有害因素的空间。分为封闭或部分封闭设备、地下封闭或部分封闭空间、地上封闭或部分封闭空间三大类。     

石油化工灾害事故处置应把握的关键环节

石油化工设施具有易燃易爆、有毒有害、高温高压和生产连续的行业特点,决定了火灾的复杂性、突发性和危险性,处置难度大、技术要求高,极易造成大量人员伤亡和巨额财产损失。在石油化工火灾处置过程中,应把握灭火救援中关键环节,科学、有效、安全处置。     

作业现场“三违”行为的剖析与对策

据国家安全生产监督管理局统计,92%事故发生的直接原因都是"三违"行为造成的。重庆开县"12.23"特别重大事故,是由于起钻杆时,违犯操作规程,没有灌泥浆,液柱压力低于地层原始压力所致,造成人243人死亡,直接经济损失9200多万元。事故造成的伤亡惨重,损失巨大,教训沉痛,充分暴露出"三违"行为危害的严重性,     

矿井防灭火的安全措施

一、矿井火灾的分类与危害： 矿井火灾按其发生原因可分为外因火灾和内因火灾,外因火灾是由于外部的高温热源引起可燃物的火灾。内因火灾是由于煤炭（或其它可燃物）在空气中氧化并聚积热量而引起的火灾。矿井火灾的危害主要表现在以下几个方面：1、火灾产生大量的有毒有害气体,主要是一氧化碳和烟雾,严重地威胁着井下人员生命安全。