Background/Aim: Rapid spread of resulted in the revision of the value of ultraviolet C (UVC) sterilization in working spaces. This study aimed at investigating the UVC sensitivity of eighteen malignant and nonmalignant cell lines, the protective activity of sodium ascorbate against UVC, and whether Dectin-2 is involved in UVC sensitivity. Materials and Methods: Various cell lines were exposed to UVC for 3 min, and cell viability was determined using the MTT assay. Anti-UV activity was determined as the ratio of 50% cytotoxic concentration (determined with unirradiated cells) to 50% effective concentration (that restored half of the UV-induced loss of viability). Dectin-2 expression was quantified using flow cytometry. Results: The use of culture medium rather than phosphate-buffered saline is recommended as irradiation solution, since several cells are easily detached during irradiation in phosphate-buffered saline. Oral squamous cell carcinoma cell lines showed the highest UV sensitivity, followed by neuroblastoma, glioblastoma, leukemia, melanoma, lung carcinoma cells, and normal oral and dermal fibroblasts. Human dermal fibroblasts were more resistant than melanoma cell lines; however, both expressed Dectin-2. Sodium ascorbate at micromolar concentrations eliminated the cytotoxicity of UVC in these cell lines. Conclusion: Normal cells are generally UVC-resistant compared to corresponding malignant cells, which have higher growth potential. Dectin-2 protein expression itself may not be determinant of UVC sensitivity.In December 2019, several cases of pneumonia with unknown etiology emerged in Wuhan, China. From the throat swab sample of a patient, a novel coronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) was identified, and the disease was named coronavirus disease 2019 (COVID-19) (1). Coronavirus infects the transbronchial and alveolar epithelial cells, inducing lung damages and other organ impairments (2). The COVID-19 disease causes psychological and physical complications (3).Environmental sodium hypochlorite cleaning and wearing masks effectively prevent infection of healthcare workers of hospitals, clinics, and schools. Also, the risk of infection in contaminated rooms can be reduced by disinfection with ultraviolet C (UVC) (4, 5). Intensive Care Units at the University Hospital use six 15 W low-vapor-pressure mercury lamps emitting 253.7 nm UVC [the average dose rate in the UVC cabinet was (2.7±0.5) mW/cm 2 ] (6). This value is about 27,000-fold higher than the effective and safe irradiation intensity for skin application (UVB: 0.1 μW/cm 2 ) (7). UVC disinfection lamps, which have strong bactericidal and virucidal power, have been solely used to improve indoor air quality in hospitals. Therefore, with increased time spent in such areas, their harmful effect on humans (such as skin cancer and cataract) may be augmented. If sterilization lamps are introduced at home, it would be necessary for us to protect ourselves from the injuring effects of UVC. It has been reported that Dectin...
