Bauer Stefan, Holtschmidt Hans, Ott Günter
Unit Physical Agents, Federal Institute for Occupational Safety and Health (BAuA), Dortmund, Germany.
Laboratory for Biosensory Systems, BioSense, Bornheim, Germany.
J Photochem Photobiol B. 2018 Jan;178:69-75. doi: 10.1016/j.jphotobiol.2017.10.027. Epub 2017 Oct 28.
Disinfection by pulsed ultraviolet (UV) radiation is a commonly used method, e.g. in industry or medicine and can be carried out either with lasers or broadband UV radiation sources. Detrimental effects to biological materials depending on parameters such as pulse duration τ or pulse repetition frequency f are well-understood for pulsed coherent UV radiation, however, relatively little is known for its incoherent variant. Therefore, within this work, it is the first time that disinfection rates of pulsed and continuous (cw) incoherent UV radiation studied by means of spore film dosimetry are presented, compared with each other, and in a second step further investigated regarding two pulse parameters. After analyzing the dynamic range of the Bacillus subtilis spore films with variable cw radiant exposures H=5-100Jm a validation of the Bunsen-Roscoe law revealed its restricted applicability and a 28% enhanced detrimental effect of pulsed compared to cw incoherent UV radiation. A radiant exposure H=50Jm and an irradiance E=0.5Wm were found to be suitable parameters for an analysis of the disinfection rate as a function of τ=0.5-10ms and f=25-500Hz unveiling that shorter pulses and lower frequencies inactivate more spores. Finally, the number of applied pulses as well as the experiment time were considered with regard to spore film disinfection.
脉冲紫外线（UV）辐射消毒是一种常用方法，例如在工业或医学领域，可通过激光或宽带紫外线辐射源进行。对于脉冲相干紫外线辐射，取决于脉冲持续时间τ或脉冲重复频率f等参数对生物材料的有害影响已得到充分理解，然而，对于其非相干变体，人们了解相对较少。因此，在本研究中，首次通过孢子膜剂量测定法研究了脉冲和连续（cw）非相干紫外线辐射的消毒率，相互进行比较，并在第二步中针对两个脉冲参数进一步研究。在分析了枯草芽孢杆菌孢子膜在可变连续波辐射暴露量H = 5 - 100 J/m²下的动态范围后，对本生 - 罗斯科定律的验证揭示了其适用性受限，且与连续波非相干紫外线辐射相比，脉冲辐射的有害效应增强了28%。发现辐射暴露量H = 50 J/m²和辐照度E = 0.5 W/m²是分析消毒率随τ = 0.5 - 10 ms和f = 25 - 500 Hz变化的合适参数，结果表明较短的脉冲和较低的频率能使更多孢子失活。最后，考虑了施加脉冲的数量以及关于孢子膜消毒的实验时间。
