紫外消毒系统有效辐射剂量测试方法研究进展

近年来,紫外消毒技术在水处理领域的应用越来越广泛,然而关于其辐射剂量的测试方法在国内外的发展还较为缓慢,特别是目前国内还没有机构能够采用标准的生物剂量法来对紫外消毒系统内部的有效辐射剂量进行验证. 因此介绍了国际上几种主要的紫外剂量测试方法,包括生物剂量法、化学法和模型计算法,并分析了各自的优缺点和应用中存在的问题,同时探讨了几种新开发的测试方法及其应用前景,以期为紫外消毒技术在水处理领域的推广应用提供支持.     

风险污染物短期高剂量暴露下的生态风险评估方法

水污染事故的短期高剂量暴露造成的急性生态危害及水生生物安全问题成为人们研究的重点,但我国以往的水污染事故,多采用地表水环境质量标准和生活饮用水卫生标准来判断水体是否安全,缺乏对水生生物保护的安全效应阈值或风险值.国外在水生生物保护方面,虽然限定了一些风险污染物对水生生物的安全效应阈值或称为无效应阈值或风险值,但其无效应阈值的计算是基于长期暴露下的慢性毒性值,其生态风险值也是基于长期暴露下的风险,缺少对水污染事件短期高剂量暴露下化学品的阈值限定及风险评估.本研究结合常规生态风险评价的理念及美国EPA短期暴露情况下保护水生生物基准值的制定方法,探讨了水污染事件的短期高剂量暴露情况下风险污染物的生态风险评价及生态效应阈值的计算方法,并进行了实例应用,同时对建立我国水污染事故生态风险评估方法体系提出了建议.     

Potential health risks due to toxic contamination in the ambient environment of certain Indian states

Toxic or hazardous substances pose two types of risks in the environment, namely `short-term or acute risk' and `long-termor chronic risk'. The short-term risk is associated with the one-time acute exposure to potentially hazardous substancesaccidentally released in the environment, whereas the long-termrisk is resulted from continuous exposure to potentially harmfulsubstances present in different environmental media. This articledeals with the assessment of potential health risks related to certain carcinogens and non-carcinogens (e.g. cadmium, chromiumand nickel) present in three environmental media, viz. air, waterand food in different Indian states (regions). Appropriate dose-response models have been identified and used for this purpose with the assumptions and input data as per the Indian context. Mean values of ambient air concentration levels of Cd,Cr and Ni have been used to estimate the individual and societalrisks of extra cancer in different states of India. The hazardquotients and hazard index representing the non-carcinogenic chronic health effects caused by chromium and cadmium due to their long-term exposure through water and food have also beenestimated. The risk results have been compared with the diseasesurveillance data. A definite correlation between the estimatedrisk results and the reported number of lung cancer cases and chronic liver diseases have been observed in different regions. As a matter of fact, it is not possible to derive precise risk estimates due to various uncertainties included both in availabledata and in the models which are used to calculate potency factors and effective concentration. However, average risk levelsas estimated and presented in this article are quite useful forplanning purposes.     

An approach to comparative assessments of potential health risks from exposure to radionuclides and hazardous chemicals

The need to compare potential health risks to the public associated with different activities that can result in releases of hazardous substances to the environment is becoming increasingly important in decision-making. In making such comparisons, it is desirable to use equivalent indicators of potential health risks for radionuclides, chemical carcinogens, and noncarcinogenic hazardous chemicals. Current approaches to risk assessment that were developed for purposes of protecting human health do not provide equivalent indicators of potential risks from exposure to radionuclides and hazardous chemicals. Comparisons of environmental concentrations or calculated exposures or risks with standards for protection of public health also do not provide equivalent indicators of potential risks. We propose a simple approach to comparative risk assessments in which calculated exposures to any hazardous substances are expressed relative to no-observed-effect levels (NOELs) or, preferably, lower confidence limits of benchmark doses (BMDLs) in humans. This approach provides an equivalent, science-based indicator of the relative risks posed by different exposures to any hazardous substances.     

浅谈纳氏试剂法测定空气中氨的影响因素

在分析用纳氏试剂分光光度法测定空气中氨的各种误差因素,重点研究了由于吸收液受到空气的污染和吸收瓶对氨的吸附残留影响.得出结论是:在本地空气中氨的背景浓度水平为0.100 mg/m3时,吸收液污染和吸收瓶污染相对影响最高达到47%.     

SRDAAR-QNPP:a computer code system for the real-timedose assessment of an accident releasefor Qinshan Nuclear Power Plant

ＳＲＤＡＡＲ－ＱＮＰＰ：ａｃｏｍｐｕｔｅｒｃｏｄｅｓｙｓｔｅｍｆｏｒｔｈｅｒｅａｌ－ｔｉｍｅｄｏｓｅａｓｓｅｓｓｍｅｎｔｏｆａｎａｃｃｉｄｅｎｔｒｅｌｅａｓｅｆｏｒＱｉｎｓｈａｎＮｕｃｌｅａｒＰｏｗｅｒＰｌａｎｔＨｕＥｒｂａｎｇ;ＷａｎｇＨａｎ（Ｃｈ...     

上海市水体中人工放射性水平调查及评价

调查了１９８９－１９９１年不海市各类水体中人工放射性核素的水平。调查共设点１５个，采集枯、丰水期水样４５个，结果表明，上海市各类水体中＾９０Ｓｒ、＾１３７Ｃｓ和总β放射性浓度均低于国家生活饮用水卫生限制标准，属正常本底水平。按调查结果估算的上海市居民从饮水中摄入的人工放射性核素＾９０Ｓｒ、＾１３７Ｃｓ、＾３Ｈ，所致人均年有效剂量为３．８×１０＾－７ＳＶ，与全国均值相吻合。     

室内空气质量相关标准与评价方法进展

综述了国内外室内空气质量(IAQ)标准、建筑装饰装修材料中有害物质限量标准和室内空气质量评价方法研究的进展情况。根据浓度一呼吸速率一剂量的关系,提出了“参考剂量评价标准”的概念和将来应开展工作的建议。     

哈密地区环境中氡及其子体浓度所致居民剂量评价

用双滤膜法和Ｔｈｏｍａｓ三段法测定了哈密地区环境空气中氡及其子体浓度．结果表明，室内氡及其子体浓度平均值分别为２８．ＯＢｑ·ｍ－３和７．５×１０－８Ｊ·ｍ－３，室外氡及其子体浓度平均值分别为１０．７Ｂｑ·ｍ－３和３．１×１０－３Ｊ·ｍ－３．氡及其子体所致居民人均有效剂量当量为１．０３ｍＳｖ·ａ－１，集体有效剂量当量为４．２×１０２ｍａｎ·Ｓｖ．     

环境地表γ辐射剂量率测量比对结果分析

本文介绍了我站环境地表γ辐射剂量率测量仪表的比对结果，发现目前我站的γ辐射剂量率测量仪表工作状况较好。