Chlorine Truck Attack Consequences and Mitigation

We develop and apply an integrated modeling system to estimate fatalities from intentional release of 17 tons of chlorine from a tank truck in a generic urban area. A public response model specifies locations and actions of the populace. A chemical source term model predicts initial characteristics of the chlorine vapor and aerosol cloud. An atmospheric dispersion model predicts cloud spreading and movement. A building air exchange model simulates movement of chlorine from outdoors into buildings at each location. A dose‐response model translates chlorine exposures into predicted fatalities. Important parameters outside defender control include wind speed, atmospheric stability class, amount of chlorine released, and dose‐response model parameters. Without fast and effective defense response, with 2.5 m/sec wind and stability class F, we estimate approximately 4,000 (half within ～10 minutes) to 30,000 fatalities (half within ～20 minutes), depending on dose‐response model. Although we assume 7% of the population was outdoors, they represent 60–90% of fatalities. Changing weather conditions result in approximately 50–90% lower total fatalities. Measures such as sheltering in place, evacuation, and use of security barriers and cryogenic storage can reduce fatalities, sometimes by 50% or more, depending on response speed and other factors.     

Should Cities Invest in Sheltering‐in‐Place Measures Against Chlorine Truck Attacks by Terrorists?

After an intentional release of chlorine in an office district, public responses such as sheltering‐in‐place could save many lives if rapid enough. However, previous work does not estimate how fast and effective such responses would be for several possible investments in attack detection, public alert, and building ventilation, nor whether such measures would be cost effective. We estimate public response times with investment options in place, and resulting changes in fatalities as well as system costs, including false alarm costs, and cost effectiveness in terms of cost per net death avoided. The measures do have life‐saving potential, especially if all response times are at or near the lower limits of the ranges assumed in this article. However, due to uncertainties, it is not clear that responses would be rapid enough to save many people. In some cases total fatalities would increase, since sheltering after chlorine vapor has already entered buildings can increase occupants’ chlorine exposure. None of the options considered have median cost per statistical life saved meeting a cost‐effectiveness threshold of $6.5 million across all of the chlorine exposure dose‐response and ingress‐delay models considered here, even if there were one attack per year in the area covered by the system. Given these and other issues discussed in this article, at this point investments to improve sheltering‐in‐place capability appear not to be robust strategies for reducing fatalities from chlorine attack in an office district.     

二氧化氯在泳池水净化中的应用

从保护游泳者的健康与安全出发 ,介绍了替代液氯和其它氯制品消毒剂的新一代消毒剂———二氧化氯。着重描述二氧化氯的物化性质 ,并就其在泳池水净化中的应用原理和制备方法进行讨论     

氯离子的交流示波极谱滴定

本文提出用氯离子本身在选定的极谱底液中,交流示波极谱图上呈现一灵敏切口,用硝酸银标准溶液滴定至切口消失,以指示滴定终点。该法具有快、简、准的优点,为氯离子的交流示波极谱滴定开辟了一条新路。     

二氧化氯的生产和应用

本文综述了二氧化氯的多种生产方法和应用背景,分析了它们的特点和不足,为实验研究和工业化生产提供了一份有益的参考资料。     

基于投影法的产品方案筛选评价模型研究

在当今复杂多变的市场经济环境下,很多企业通过延伸产品线来提高企业抵御风险的能力,从而面临产品多方案选择的问题。本文构建了基于投影法的产品方案筛选评价模型,首先根据市场、环境与产业政策以及企业实际需求三个原则进行筛选,然后从经济、社会和环境因素三个方面建立评价指标体系,采用投影法对筛选出的产品方案进行评价,并以某氯碱化工企业液氯产品多方案选择为例,证实了模型的有效性。     

The Possibility for "Natural" Generation of Chlorinated Organic Compounds

There is continuing concern for the exposure of persons to various chlorinated organics via the environment, for example, chlorinated disinfection byproducts in drinking water.⁽¹⁾ Some of these may be carcinogenic,⁽²⁾ although the evidence is far from strong.⁽³⁾ There is an accumulating body of evidence that one of the normal human immunological responses to foreign agents is the generation of hypochlorous acid. This evidence will be summarized. The possibility that this HOCl generated in vivo could result in the formation of organo-chlorine compounds does not appear to have been seriously considered. Based on best available information, the amount of such byproduct formation will be estimated.