Gas-phase organics in environmental tobacco smoke: 2. Exposure-relevant emission factors and indirect exposures from habitual smoking

Sorption of emitted gas-phase organic compounds onto material surfaces affects environmental tobacco smoke (ETS) composition and exposures indoors. We have introduced a new metric, the exposure relevant emission factor (EREF) that accounts for sorptive uptake and reemission to give the mass of individual ETS constituents available for exposure over a day in which smoking occurs. This paper describes month-long experiments to investigate sorption effects on EREFs and potential ETS exposures under habitual smoking conditions. Cigarettes were smoked in a 50-m³ furnished room over a 3-h period 6–7 days per week, with continuous ventilation at 0.3, 0.6, or 2.1 h⁻¹. Organic gas concentrations were measured every few days over 4-h “smoking”, 10-h “post-smoking” and 10-h “background” periods. Concentration patterns of volatile ETS components including 1,3-butadiene, benzene and acrolein were similar to those calculated for a theoretical non-sorbing tracer, indicating limited sorption. Concentrations of ETS tracers, e.g. 3-ethenylpyridine (3-EP) and nicotine, and lower volatility toxic air contaminants including phenol, cresols, and naphthalene increased as experiments progressed, indicating mass accumulation on surfaces and higher desorption rates. Daily patterns stabilized after week 2, yielding a steady daily cycle of ETS concentrations associated with habitual smoking. EREFs for sorbing compounds were higher under steady cycle versus single-day smoking conditions by 50% for 3-EP, and by 2–3 times for nicotine, phenol, cresols, naphthalene, and methylnaphthalenes. Our results provide relevant information about potential indirect exposures from residual ETS (non-smoker enters room shortly after smoker finishes) and from reemission, and their importance relative to direct exposures (non-smoker present during smoking). Under the conditions examined, indirect exposures accounted for a larger fraction of total potential exposures for sorbing versus non-sorbing compounds, and at lower versus higher ventilation rates. Increasing ventilation can reduce indirect exposures to very low levels for non-sorbing ETS components, but indirect routes accounted for 50% of potential nicotine exposures during non-smoking periods at all ventilation rates.     

宁波市危险废物管理、处置现状和对策

对宁波市危险废物现状进行了调查,分析了危险废物的来源、产量、特征及存在的主要问题.在此基础上,提出了宁波市危险废物管理处置对策,具体包括:加强危险废物申报登记工作;健全宁波市危险废物管理法律体系和监督管理机构;建立合理的危险废物收费制度;源头控制危险废物污染和建设危险废物集中处置场等.     

关于工业危险废物固化与浸出试验的研究

工业危险废物在进行安全填埋前，需进行稳定化／固化处理，以减少毒性。本文主要是通过对几种工业固体废物固化与浸出实验的分析与研究，优化出理想的固化方案和固化工艺参数。     

浅议内蒙古固体危险废物的处置现状及管理对策

本文主要介绍内蒙古工业固体危险废物的来源、分布，处理、处置现状，目前存在的问题，经分析提出适合内蒙古区情的处置方法及相应管理对策建议，供政府及决策部门参考。     

高含铁废酸液处置工程实例

某煤业有限公司清洗锅炉产生的废液中含有大量的铁离子与H^+,具有腐蚀性危险特性,属于危险废物。本工程实例利用酸碱中和及氧化絮凝沉淀的原理,消除了该废酸液的腐蚀性危险特性,同时降低了废酸液中的铁离子以及废酸液的色度、浊度,为后续的深度治理提供了便利。对高含铁废酸液的治理有一定的借鉴意义。     

危险废物鉴别实验室能力建设浅析

介绍我国危险废物鉴别体系的组成,分析了2007版《危险废物鉴别标准》的相关内容,探讨了在危险废物鉴别实验室能力建设中,场地条件、硬件设备、人员技能3方面的要求。指出目前环境监测部门开展危险废物鉴别存在的问题和难点,有针对性地提出建议与措施。     

Historical analysis of U.S. onshore hazardous liquid pipeline accidents triggered by natural hazards

Incidents at U.S. onshore hazardous liquid pipeline systems were analyzed with an emphasis on natural hazards. Incidents triggered by natural hazards (natechs) were identified by keyword-based data mining and expert review supplemented by various data sources. The analysis covered about 7000 incidents in 1986–2012, 3800 of which were regarded as significant based on their consequences. 5.5% of all and 6.2% of the significant incidents were found to be natechs that resulted in a total hazardous substance release of 317,700 bbl. Although there is no trend in the long-term yearly occurrence of significant natechs, importance is found to be increasing due to the overall decreasing trend of the incidents. Meteorological hazards triggered 36% of the significant natechs, followed by geological and climatic hazards with 26% and 24%. While they occurred less frequently, hydrological hazards caused the highest amount of release which is about 102,000 bbl. The total economic cost of significant natechs was 597 million USD, corresponding to about 18% of all incident costs in the same period. More than 50% of this cost was due to meteorological hazards, mainly tropical cyclones. Natech vulnerabilities of the system parts vary notably with respect to natural hazard types. For some natural hazards damage is limited possibly due to implemented protection measures. The geographical distribution of the natechs indicated that they occurred more in some states, such as Texas, Oklahoma, and Louisiana. About 50% of the releases was to the ground, followed by water bodies with 28%. Significant consequences to human health were not observed although more than 20% of the incidents resulted in fires. In general, the study indicated that natural hazards are a non-negligible threat to the onshore hazardous liquid pipeline network in the U.S. It also highlighted problems such as underreporting of natural hazards as incident causes, data completeness, and explicit data limitations.     

液化危险品储罐泄漏——扩散监测及仿真预警系统

根据国家八五科技攻关专题“易燃易爆重大危险源监控及预警技术研究”技术总结报告提供的素材，通过对危险品储罐的安全状态实时监测、建立泄漏扩散预测模型及其计算机仿真装置，构成监控危险源的预警系统，为预防重大事故、保障安全生产提供技术支撑     

Risk analysis for road and rail transport of hazardous materials: a simplified approach

A simplified approach to transportation risk analysis for road and rail transport of dangerous goods is proposed, which is based on the use of a product databank, containing the impact areas for a number of pre-selected accidental scenarios, and on the selection of a few typical average values of the involved parameters, relevant to the type of transport activity and to the route. Such an approach enables also a non-specialist to very rapidly perform a transportation risk analysis, obtaining both individual and societal risk measures for the study case(s): the results may be used to support a decision making process, and/or as a basis for a more in deep analysis.     

Sydney tar ponds: some problems in quantifying toxic waste

Information on the type and amount of hazardous and toxic waste is required to develop a meaningful strategy and estimate a realistic cost for clean up of the Sydney Tar Pond site which is located on Cape Breton, in the province of Nova Scotia, Canada. The site covers the area of the decommissioned Sysco (Sydney Steel Corporation) plant. The materials of concern include BTEX (benzene, toluene, ethylbenzene, and xylenes), PAH (polycyclic aromatic hydrocarbons), PCB (polychlorinated biphenyl), and particulates laden with toxic metals, such as arsenic, lead, and others. The originally nontoxic materials such as soil, blast furnace slag, and vegetation, as well as surface and ground waters, which were subsequently contaminated, must also be included if they fail tests prescribed by environmental regulations. An extensive sampling program must be undertaken to obtain data for an accurate estimate of the waste to be cleaned and disposed of. Apparently, 700,000 tons of toxic waste, which is believed to be present on the site, may represent only a fraction of the actual amount. The clean-up of the site is only part of the solution. Toxic waste has to be disposed of in accordance with environmental regulations.