Characterization of a low-cost recycled UV-C light source and assessment of its germicidal activity against bacteria and viruses

Abstract

INTRODUCTION: Since the COVID-19 pandemic, there has been an increased demand for UV-C radiation as a disinfectant agent for surfaces and enclosed spaces. While this disinfection mechanism is well-known, the devices used are very large and expensive. This study addressed a reliable, versatile, accessible and very low-cost UV-C source. The main objective was to characterize and evaluate the germicidal efficacy of a UV-C source, consisting of a quartz bulb found inside commercial public lighting fixtures. METHODS: For spectral characterization, an Acton Research Corporation VM-504 monochromator was used and irradiance was measured with a specifically designed and manufactured sensor. To analyze the germicidal action, radiation studies were carried out on different strains of bacteria and viruses. The spectral characteristics of the chosen source were studied and compared to the commercial one. The bactericidal and virucidal power was evaluated in laboratory samples, confirmed with four types of bacteria and one virus. RESULTS: It was demonstrated that the radiation generated by this source eliminated all bacteria within 30 seconds of exposure and within 1 minute in the case of the virus, both tests at a distance of 300 mm. DISCUSSION: This equaled or even surpassed the germicidal power of a commercial source in some cases.