Effects of relative humidity on the ultraviolet induced inactivation of airborne bacteria
Effects of relative humidity on the ultraviolet induced inactivation of airborne bacteria
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DOI：
10.1080/02786820152546770
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发表时间：
2001-09-01
影响因子：
5.2
通讯作者：
Hernandez, M
中科院分区：
文献类型：
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作者：
Peccia, J;Werth, HM;Hernandez, M
紫外线杀菌照射 (UVGI) 作为一种针对感染性生物气溶胶的工程控制方法，需要清楚地了解环境对灭活率的影响。在 0.8 m(3) 完全混合室中，在不同相对湿度 (RH) 水平下评估雾化粘质沙雷氏菌、枯草芽孢杆菌和副偶然分枝杆菌对紫外线照射的响应。生物气溶胶反应的特征在于物理因素，包括中值细胞空气动力学直径和细胞水吸附能力，以及通过直接显微镜计数和标准平板计数确定的自然衰减和UNI诱导的失活率。所有生物体均在相对湿度 20% 至 95% 之间测试了从大气中吸附的水分（相对湿度 95% 时高达干细胞质量的 70%）；然而，在相同的相对湿度范围内，没有观察到中值空气动力学直径随之变化。紫外线球形辐照度的变化很小，在 20-95% RH 范围内不具有统计显着性。对于每种测试的纯培养物，细胞水吸附和失活反应相似：当 R-H 超过约 50% 时，吸附显着增加，并且观察到紫外线诱导的失活率同时急剧下降。
Ultraviolet germicidal irradiation (UVGI) as an engineering control against infectious, bioaerosols necessitates a clear understanding of environmental effects on inactivation rates. The response of aerosolized Serratia marcescens, Bacillus subtilis, and Mycobacterium parafortuitum to ultraviolet irradiation was assessed at different relative humidity (RH) levels in a 0.8 m(3) completely-mixed chamber. Bioaerosol response was characterized by physical factors including median cell aerodynamic diameter and cell water sorption capacity and by natural decay and UNI-induced inactivation rate as determined by direct microscopic counts and standard plate counts. All organisms tested sorbed water from the atmosphere at RH levels between 20% and 95% (up to 70% of dry cell mass at 95% RH); however, no concomitant change in median aerodynamic diameter in this same RH range was observed. Variations in ultraviolet spherical irradiance were minor and not statistically significant in the 20-95% RH range. Cell water sorption and inactivation response was similar for each of the pure cultures tested: when R-H exceeded approximately 50%, sorption increased markedly and a sharp concurrent drop in UV-induced inactivation rate was observed.