Optimization of an ultraviolet LED radiation system for COVID-19 disinfection and sterilization

紫外线杀菌照射(UVGI，254 nm)可有效灭活或杀灭微生物。这导致了许多应用，包括对具有传染性的空气颗粒物进行消毒，以及对医疗保健环境中的设备和表面进行消毒。然而，UVGI的有效性取决于存在的微生物类型、受污染的表面或材料以及培养环境(液体或固体)。因此，UVGI的有效性需要针对特定场景进行测试。研究了不同细菌和病毒对UVGI敏感性的研究通常会确定将细菌细胞数量减少一个对数量级所需的紫外线辐照度，该值的范围为13至73.3W·m-2。需要根据不同的环境环境调整不同的辐照度水平，例如个人防护设备(PPE)、手持设备、食品准备或自动售货机场所和大面积表面的净化。为应对新冠肺炎疫情，我们的目标是优化紫外线发光二极管辐射(254 Nm)系统，用于不同表面的消毒或灭菌。这项工作利用我们在LED技术和改进的LED配置方面的重要专业知识，为我们与行业合作伙伴(U Technology)正在进行的合作研究增加了新的和及时的元素。重要的是，麦吉尔大学生物资源工程、微生物学和免疫学系之间的内部合作加强了它。对紫外线照射剂量和覆盖面积的深入研究将有助于改进紫外线LED照射系统，更好地了解紫外线照射对病原体(包括SARS-CoV-2)的有效性，并有助于缓解新冠肺炎在医疗保健环境、长期设施护理或其他室内空间的传播。

Ultraviolet germicidal irradiation (UVGI, 254-nm) effectively inactivates or kills microorganisms. This has led to numerous applications, including disinfection of infectious airborne particles and sterilization of equipment and surfaces in healthcare settings. However, the effectiveness of UVGI is dependent upon types of microorganisms present, the contaminated surface or material, and culture environment (liquid or solid). As such, the efficacy of UVGI requires scenario-specific testing. Studies that have investigated UVGI sensitivities of different bacteria and viruses often determine the UV irradiance level required to decrease the bacterial cell number by one logarithmic order, and this value ranges from 13 to 73.3 W-m-2. Different irradiance levels need to be adjusted according to different environmental settings, such as decontamination of personal protective equipment (PPE), hand-held equipment, food preparation or vending premises and large surface areas. In response to the COVID-19 pandemic, we aim to optimize an ultraviolet light emitting diode (LED) radiation (254 nm) system for disinfection or sterilization of different surfaces. This work adds a new and timely element to our ongoing collaborative research with our industry partner (U Technology) by using of our significant expertise in LED technology and modified LED configurations. Importantly, it is strengthened by an intra-institutional collaboration between the Departments of Bioresource Engineering and Microbiology and Immunology at McGill University. This in-depth study on UVGI dosage and coverage area will allow for improvements to a UV-LED irradiation system, better our understanding of the effectiveness of UVGI on pathogens, including SAR-CoV-2, and help mitigate the transmission of COVID-19 in healthcare settings, long-term facility-based care or other indoor spaces.