Sinclair Lucy G, Dougall Laura R, Ilieva Zornitsa, McKenzie Karen, Anderson John G, MacGregor Scott J, Maclean Michelle
The Robertson Trust Laboratory for Electronic Sterilisation Technologies, Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK.
Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK.
Health Technol (Berl). 2023 Jun 14:1-15. doi: 10.1007/s12553-023-00761-3.
Lighting systems which use visible light blended with antimicrobial 405-nm violet-blue light have recently been developed for safe continuous decontamination of occupied healthcare environments. This paper characterises the optical output and antibacterial efficacy of a low irradiance 405-nm light system designed for environmental decontamination applications, under controlled laboratory conditions.
In the current study, the irradiance output of a ceiling-mounted 405-nm light source was profiled within a 3×3×2 m (18 m) test area; with values ranging from 0.001-2.016 mWcm. To evaluate antibacterial efficacy of the light source for environmental surface decontamination, irradiance levels within this range (0.021-1 mWcm) at various angular ( ϴ=0-51.3) and linear (∆s=1.6-2.56 m) displacements from the source were used to generate inactivation kinetics, using the model organism, . Additionally, twelve bacterial species were surface-seeded and light-exposed at a fixed displacement below the source (1.5 m; 0.5 mWcm) to demonstrate broad-spectrum efficacy at heights typical of high touch surfaces within occupied settings.
Results demonstrate that significant (P≤0.05) inactivation was successfully achieved at all irradiance values investigated, with spatial positioning from the source affecting inactivation, with greater times required for inactivation as irradiance decreased. Complete/near-complete (≥93.28%) inactivation of all bacteria was achieved following exposure to 0.5 mWcm within exposure times realistic of those utilised practically for whole-room decontamination (2-16 h).
This study provides fundamental evidence of the efficacy, and energy efficiency, of low irradiance 405-nm light for bacterial inactivation within a controlled laboratory setting, further justifying its benefits for practical infection control applications.
最近已开发出使用与抗菌405纳米紫蓝光混合的可见光的照明系统，用于对有人占用的医疗环境进行安全的连续净化。本文在受控实验室条件下，对一种设计用于环境净化应用的低辐照度405纳米光系统的光输出和抗菌效果进行了表征。
在本研究中，对安装在天花板上的405纳米光源在3×3×2米（18立方米）测试区域内的辐照度输出进行了分析；值范围为0.001 - 2.016毫瓦/平方厘米。为了评估光源对环境表面净化的抗菌效果，在该范围内（0.021 - 1毫瓦/平方厘米），从光源以不同角度（ϴ = 0 - 51.3）和线性（∆s = 1.6 - 2.56米）位移的辐照度水平用于使用模式生物生成灭活动力学。此外，将十二种细菌接种在表面并在光源下方固定位移（1.5米；0.5毫瓦/平方厘米）处进行光照，以证明在有人占用环境中高接触表面典型高度下的广谱效果。
结果表明，在所研究的所有辐照度值下均成功实现了显著（P≤0.05）的灭活，光源的空间定位影响灭活效果，随着辐照度降低，灭活所需时间更长。在实际用于全室净化（2 - 16小时）的暴露时间内，暴露于0.5毫瓦/平方厘米后，所有细菌均实现了完全/近乎完全（≥�3.28%）的灭活。
本研究提供了低辐照度405纳米光在受控实验室环境中对细菌灭活的有效性和能源效率的基本证据，进一步证明了其在实际感染控制应用中的益处。
