Buonanno Manuela, Hashmi Raabia, Petersen Camryn E, Tang Zheng, Welch David, Shuryak Igor, Brenner David J
Columbia University.
Res Sq. 2024 Dec 3:rs.3.rs-5129114. doi: 10.21203/rs.3.rs-5129114/v1.
Scientific bodies overseeing UV radiation protection recommend safety limits for exposure to ultraviolet light in the workplace based on published peer-reviewed data. To support this goal, a 3D model of the human cornea was used to assess the wavelength dependence of corneal damage induced by UVC light. In the first set of experiments the models were exposed with or without simulated tears; at each wavelength (215-255 nm) cells with DNA dimers and their distribution within the epithelium were measured. Simulated tears reduced the fraction of damaged cells to an extent dependent on the wavelength and tissue layer. Another set of models were exposed without tears; yields of DNA-damaged cells and their distribution within the corneal epithelium were evaluated at each wavelength, together with other markers of cell and tissue integrity. Unlike relatively longer wavelengths, the range commonly referred to as far-UVC (215-235 nm) only induced dimers in the uppermost layers of the epithelium and did not result in lasting damage or halt proliferation of the germinative cells. These results provide evidence for the recommended exposure limits for far-UVC wavelengths, which have been proposed as a practical technology to reduce the risk of transmission of airborne diseases in occupied locations.
负责监督紫外线辐射防护的科学机构会根据已发表的同行评审数据，推荐工作场所紫外线照射的安全限值。为支持这一目标，利用人角膜的3D模型评估了UVC光诱导的角膜损伤的波长依赖性。在第一组实验中，对模型进行有或无模拟泪液的照射；在每个波长（215 - 255纳米）下，测量含有DNA二聚体的细胞及其在上皮内的分布情况。模拟泪液将受损细胞的比例降低到一定程度，该程度取决于波长和组织层。另一组模型在无泪液的情况下进行照射；在每个波长下评估DNA受损细胞的产量及其在角膜上皮内的分布，以及细胞和组织完整性的其他标志物。与相对较长的波长不同，通常称为远UVC（215 - 235纳米）的波长范围仅在上皮的最上层诱导二聚体形成，并不会导致持久损伤或停止生发细胞的增殖。这些结果为远UVC波长的推荐暴露限值提供了证据，远UVC波长已被提议作为一种实用技术，以降低在有人场所空气传播疾病传播的风险。
