UV RADIATION FOR AIR DISINFECTION

Abstract

Disinfection for air, water, and surfaces has been arised public interest and improved along the technology development. Disinfection with UV is included in the development and have been approved for its benefit to inactivate pathogens. It also cause the increasing number of UV disinfection product on the market. This paper aims to explain and describe the information about the utilization of Ultraviolet radiation as a disinfection. This article discusses about the UV radiation for air disinfection, the wavelength of UV, the Recommended dose of UV, the effectiveness of UV disinfection, and the safety concern in respect of UV radiation for air disinfection. UV disinfection is an energy-based disinfection method that uses UV doses at specific wavelengths to inactivate microorganisms. UV irradiation is traditionally divided into four regions; UVA (315–400 nm), UVB (280–315 nm), UVC (200–280 nm) and vacuum UV (VUV, 100–200 nm). The effect of UV irradiation on microorganisms is called "inactivation" instead of "killing". UVGI is the use of UV irradiation in the wavelength of 200-320 nm fitted with the germicidal range to disinfect air and surfaces. UVGI is generally set at the UV wavelength of 253.7 nm (UV-C). In its mechanism, UVC radiation raised a particular interest because it induces a direct germicidal effect by causing the formation of cyclobutene pyrimidine dimers (CPDs), the main photoproducts in DNA. DNA damage can be repaired through enzymatic reactions, and the mechanism depends on the species of the microorganism, UV fluency, temperature, and physiological conditions. UVGI has been used as a support for mechanical ventilation to deactivate infectious agents in the air as a health protector for building occupants. UVGI is widely applied in the form of upper-room air application, in-duct application, HEPA-UV ceiling units, and portable fans with UVGI. The effectiveness of UV in air disinfection depends on the sensitivity of UV to the airborne microorganisms, the level of UV radiation, and the air volume exposed by UV. Disinfection with UV is considered effective in reducing microorganisms that cause health problems in humans. The aspects that affect the effectiveness of UVGI are the radiation level of radiation, the time span of radiation, room configuration, lamp placement, lamp life, air movement patterns, and air humidity levels.