Measurement of ventilation and airborne infection risk in large naturally ventilated hospital wards
Measurement of ventilation and airborne infection risk in large naturally ventilated hospital wards
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DOI：
10.1016/j.buildenv.2013.03.006
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发表时间：
2013-07-01
影响因子：
7.4
通讯作者：
Noakes, C. J.
中科院分区：
文献类型：
--
作者：
Gilkeson, C. A.;Camargo-Valero, M. A.;Noakes, C. J.
空气传播的病原体对人类健康构成重大威胁，尤其是在医院环境中，患者的免疫系统较弱。良好的通风设计可以降低风险，但是很难量化通风性能及其对感染风险的影响，特别是对于具有多个开口的大型自然通风环境。本研究应用脉冲注入气体示踪法评估自然通风环境中的潜在感染风险和局部通风率。在200 m（3）交叉通风的Nightingale病房中进行的实验表明，1-4 m/s范围内的局部外部风速导致室内通风率为每小时3.4至6.5次换气（ACH）。自然通风被证明是有效的，在开放式病房的潜在空气传播感染的风险在整个病人的位置均匀分布。与分区病房的比较突出了床之间的物理分区保护相邻患者的潜力，然而，较高的示踪剂浓度存在于附近和下游的源。关闭窗户以代表冬季条件大大增加了感染风险，与打开窗户的情况相比，对示踪剂的相对暴露增加了四倍。抽气风扇被证明可以缓解这个问题，这表明利用自然通风和机械通风各自优势的混合方法可以在这种和类似的环境中提供最佳的全年解决方案。(c)2013爱思唯尔有限公司保留所有权利。
Airborne pathogens pose a significant threat to human health and this is especially the case in hospital environments which house patients with weakened immune systems. Good ventilation design can reduce risk, however quantifying ventilation performance and its influence on infection risk is difficult, particularly for large naturally ventilated environments with multiple openings. This study applies a pulse-injection gas tracer method to assess potential infection risk and local ventilation rates in a naturally-ventilated environment. Experiments conducted in a 200 m(3) cross-ventilated Nightingale ward show that local external wind speeds in the range 1-4 m/s lead to indoor ventilation rates of between 3.4 and 6.5 air changes per hour (ACH). Natural ventilation is shown to be effective in open wards with an even distribution of potential airborne infection risk throughout patient locations. Comparison with a partitioned ward highlighted the potential for protecting neighbouring patients with physical partitions between beds, however, higher tracer concentrations are present in both the vicinity and downstream of the source. Closing the windows to represent winter conditions dramatically increases infection risk, with relative exposure to the tracer increased fourfold compared to the scenarios with the windows open. Extract fans are shown to alleviate this problem suggesting that a hybrid approach utilising the respective strengths of natural and mechanical ventilation may offer the best year-round solution in this and similar settings. (c) 2013 Elsevier Ltd. All rights reserved.