Discussion on effect of material on UV reflection and its disinfection with focus on Japanese Stucco for interior wall

Abstract

Research has previously shown that ultraviolet light C (UV-C) can inactivate unexpected infection. However, this type of potential disinfection is dramatically reduced for the shadow area such as under desk or medical equipment. Because the UV-C reflectance ratio is low on the general wall surfaces. We compared Stucco against the other materials to investigate whether we could improve disinfection for the shadow area. The reflectance ratios of UV-C irradiation of each material were examined, with particular attention to the rates for the author’s Modified Stucco. To evaluate the disinfection effects of the UV-C reflective lighting, colonies of E. coli and of Staphylococcus hominis were cultured in an agar media and counted over a certain time period after applying UV-C irradiation from a sterilizing lamp onto the investigation materials. The author’s Modified Stucco, produced reflectance ratios that was 11 times that of white wallpaper. This demonstrated that the UV-C reflected on the Stucco wall having optimum components and their compositions inhibited the number of E. coli and S. hominis, resulting in significantly disinfection effects on white wallpapers. The space with Modified Stucco and then irradiated by a UV-C may give a strong disinfection effect.

Radiometric Testing of Germicidal UV Products, Round 1: UV-C Towers and Whole-Room Luminaires (CALiPER Full Report)

“…For bare-lamp gonio testing, LPM lamp sockets were attached to the broad face of an unpainted 2x4 (pine lumber), so UV-C output power values for lamps in Table 12 may be somewhat overstated, and UV-C output ratios may thus be somewhat understated. Lumber appears to have about 5% reflectance at 254 nm (Smith et al 1984;Endo et al 2021).…”