Abstract

Far UV-C, informally defined as electromagnetic radiation with wavelengths between 200 and 230 nm, has characteristics that are well-suited to control of airborne pathogens. Specifically, Far UV-C has been shown to be highly effective for inactivation of airborne pathogens; yet this same radiation has minimal potential to cause damage to human skin and eye tissues. Critically, unlike UV-B, Far UV-C radiation does not substantially penetrate the dead cell layer of skin (stratum corneum) and does not reach germinative cells in the basal layer. Similarly, Far UV-C radiation does not substantially penetrate through corneal epithelium of the eye, thereby preventing exposure of germinative cells within the eye. The most common source of Far UV-C radiation is the krypton chloride excimer (KrCl*) lamp, which has a primary emission centered at 222 nm. Ozone production from KrCl* lamps is modest, such that control of indoor ozone from these systems can be accomplished easily using conventional ventilation systems. This set of characteristics offers the potential for Far UV-C devices to be used in occupied spaces, thereby allowing for improved effectiveness for inactivation of airborne pathogens, including those that are responsible for COVID-19.

摘要

远 UV-C，非正式定义为波长在 200 至 230 nm 之间的电磁辐射，具有非常适合控制空气传播病原体的特性。具体而言，远 UV-C 已被证明对灭活空气传播的病原体非常有效；然而，同样的辐射对人体皮肤和眼睛组织造成损害的可能性很小。重要的是，与 UV-B 不同，远 UV-C 辐射基本上不会穿透皮肤的死细胞层（角质层），也不会到达基底层的生发细胞。类似地，远 UV-C 辐射基本上不会穿透眼睛的角膜上皮，从而防止眼睛内的萌发细胞暴露。最常见的远 UV-C 辐射源是氯化氪准分子 (KrCl*) 灯，其主要发射波长集中在 222 nm。KrCl* 灯产生的臭氧量不大，因此可以使用传统通风系统轻松控制这些系统产生的室内臭氧。这组特性为远 UV-C 设备提供了在占用空间中使用的潜力，从而提高了空气传播病原体（包括导致 COVID-19 的病原体）灭活的有效性。