Environmental impact assessment of sprayed-on asbestos in buildings

This study evaluated the environmental impacts of sprayed-on asbestos, which had been used as insulation material in buildings, from multiple perspectives, mainly at the disposal stage. The health risks from asbestos emission and energy consumption were estimated. Two disposal scenarios were assumed for the asbestos: melting for reduced-risk disposal and ordinary packaging/landfilling. We estimated the asbestos emission and health risk in the case of packaging/landfilling, assuming uncontrolled management of the landfill site. A difficulty with introducing health-risk concepts into life cycle assessment (LCA) is the pulse–flux problem, which is discussed in the light of these estimations. In order to solve this problem, we proposed a method using a conversion factor representing exposure-dose/emission, and showed that emission could be converted into health risk. We also estimated the energy consumption for melting asbestos in the disposal stage, which can decrease the health risk. If we consider the energy consumption for the life cycle of asbestos, only a little energy is required for melting, compared with the large amount of energy saved in the use stage owing to the insulating effect of the asbestos. The trade-off relationship between health risk and energy consumption for the disposal scenarios indicated the need for weighting methods to handle trade-offs such as this. Received: July 2, 1998 / Accepted: December 20, 1999     

Metal contamination of Posidonia oceanica meadows along the Corsican coastline (Mediterranean)

The aim of this study is to determine metal (Cd, Co, Cr, Hg, Ni, Pb) concentrations in Posidonia oceanica tissues along the Corsican coastline. The results show that except for Cr, all the metals are preferentially accumulated in the blades; this is particularly interesting as it means that future metal analyses may be carried out only on the blades avoiding thus the removal of the shoots. Moreover, they show that metal concentrations may reflect the "background noise" of the Mediterranean Sea. Station 15 (Canari) can however be distinguished from the others due to its high Co, Cr and Ni concentrations. This result may be related to the presence of a previous asbestos mine, located near this station. Therefore, this study reinforces the usefulness and the relevance of Posidonia oceanica as a tracer of spatial metal contamination and as an interesting tool for water quality evaluation.     

Development of a testing method for asbestos fibers in treated materials of asbestos containing wastes by transmission electron microscopy

Appropriate treatment of asbestos-containing wastes is a significant problem. In Japan, the inertization of asbestos-containing wastes based on new treatment processes approved by the Minister of the Environment is promoted. A highly sensitive method for testing asbestos fibers in inertized materials is required so that these processes can be approved. We developed a method in which fibers from milled treated materials are extracted in water by shaking, and are counted and identified by transmission electron microscopy. Evaluation of this method by using asbestos standards and simulated slag samples confirmed that the quantitation limits are a few million fibers per gram and a few μg/g in a sample of 50 mg per filter. We used this method to assay asbestos fibers in slag samples produced by high-temperature melting of asbestos-containing wastes. Fiber concentrations were below the quantitation limit in all samples, and total fiber concentrations were determined as 47–170 × 10^?6 f/g. Because the evaluation of treated materials by TEM is difficult owing to the limited amount of sample observable, this testing method should be used in conjunction with bulk analytical methods for sure evaluation of treated materials.     

La-Cu-O/γ-Al2O3催化剂上CO和CH4氧化活性及氧性质研究

用长光路ＦＴＩＲ技术研究氟里昂替代物ＨＦＣ１５２ａ（ＣＨ３ＣＨＦ２）和ＨＣＦＣ２２（ＣＨＣｌＦ２）与ＯＨ自由基的大气光化学反应，研究了反应产物和反应机理，并对它们的环境影响和工业应用前景进行了评价．ＨＣＦＣ２２只能作为过渡性的替代物使用，而ＨＦＣ１５２ａ可以发展成为非常有价值的永久性替代物．     

Ambient monitoring of asbestos in selected Italian living areas

This paper presents the results of an intensive monitoring activity of the particulate, fall-out and soil of selected living areas in Italy with the aim to detect the asbestos concentration in air and subsequent risk of exposure for the population in ambient living environments, and to assess the nature of the other mineral phases composing the particulate matrix. Some areas were sorted out because of the presence of asbestos containing materials on site whereas others were used as blank spots in the attempt to detect the background environmental concentration of asbestos in air. Because the concentration of asbestos in ambient environments is presumably very low, and it is well known that conventional low–medium flow sampling systems with filters of small diameter (25 mm) may collect only a very small fraction of particulate over a short period, for the first time here, an intense monitoring activity was conducted with a high flow sampling system. The high flow system requires the use of large cellulose filters with the advantage that, increasing the amount of collected dust, the probability to collect asbestos fibers increases. Both the protocol of monitoring and analysis are novel and prompted by the need to increase the sensitivity towards the small number of expected fibers. With this goal, the collection of fall-out samples (the particulate falling into a collector filled with distilled water during the monitoring shift) and soil samples was also accomplished. The analytical protocol of the matrix particulate included preliminary X-ray powder diffraction (XRPD), optical microscopy and quantitative electron microscopy (SEM and TEM). Correlations with climatic trends and PM10 concentration data were also attempted.The surprising outcome of this work is that, despite the nature of the investigated site, the amount of dispersed asbestos fibers is very low and invariably lower than the theoretical method detection limits of the SEM and TEM techniques for identification and counting of asbestos fibers. The results are compared to the literature data worldwide and an updated model for asbestos fibers dispersion in ambient environments is proposed.     

氟里昂替代品降解产物TFA对生态环境的影响评价

氟里昂替代品的降解产物三氟乙酸(TFA)可以在水体中稳定存在,无明显的光解和生物降解,TFA以致在一些水体中不断累积。预计到2010年大气中TFA的含量可达到5～20pg/m3,降水中其含量可达到100～160ng/L。累积到一定的浓度时,TFA对生态系统包括动植物的危害是明显的,可抑制植物生长,并对动物造成伤害。      

Consumer product safety: Risk assessment of exposure to asbestos emissions from hand-held hair dryers

The United States Consumer Product Safety Commission (CPSC) is concerned that consumer exposure to asbestos from consumer products may present an unreasonable risk of injury. Recently, CPSC has obtained agreement by industry to cease production and distribution of hair dryers containing asbestos heat insulation. CPSC intends to broaden its investigation by selecting consumer products containing asbestos for priority attention. The Commission does not intend to make quantitative estimates of cancer risks posed by exposure to asbestos fibers in making regulatory decisions. This position may lead to a serious waste of resources for the Commission, industry, and society. The Commission should focus its initial attention on those products for which the release of asbestos is significant enough to cause an unreasonable health risk. To make a risk assessment for a particular use of asbestos, CPSC must acquire or request data on asbestos emissions and define unreasonable risk to health.In an attempt to give some meaning to the phrase risk assessment, the primary goal of this paper is to present a detailed risk assessment of exposure to asbestos from hand-held hair dryers. Several scenarios of use are presented using various assumptions regarding time of operation, mixing of fibers in a small room, rate of fiber emission, and time of exposure. The worst case analysis of the health risk of exposure to hair dryer emissions is based on several conservative assumptions and shows that the increased number of deaths per year due to respiratory cancer is 4 for the entire United States population. A more representative case analysis shows the increased number of deaths to be on the order of 0.15 per year.     

国外大气中消耗臭氧层物质及其替代物的监测概况与启示

大气中消耗臭氧层物质(ODS)及其替代物监测是科学评估履约成效的重要基础。美国等发达国家针对大气中ODS及其替代物开展了长期的网络化监测,中国相关监测起步相对较晚,基础比较薄弱。该文总结了发达国家大气中ODS及其替代物的监测经验,分析了中国的监测现状及存在的问题,提出了中国大气中ODS及其替代物监测的建议:明确监测目标,推进国家大气中ODS及其替代物监测网络建设;加快相关监测设备研发及方法研究进程,形成规范统一的监测技术体系;定期开展监测数据质量评价,加强综合分析利用。通过采取相应措施,逐步形成中国履行保护臭氧层国际环境公约的监测支撑能力。