Photocatalytic techniques to prevent and combat healthcare associated infections

Abstract

An ever-increasing rate of morbidity and mortality caused by healthcare associated infections is reported annually. Air circulation mediates contact with microbial contaminated aerosols and represents a major risk of transmitting healthcare associated infections. We propose a revolutionary technique for the protection of interior surfaces based on a photocatalytic composition with doped TiO2 or ZnO type semiconductor metal oxides which exert antimicrobial effect. In principle, there is an activation of the photocatalytic coating with light from the normal lighting apparatus, which may incorporate one or more sources of photocatalytic excitation light. By studying the air circulation in the hospital, it is possible to design light fixtures with specific design of light distribution, in order to perform the disinfection of the air and surfaces and to amplify the antimicrobial effect. The disinfection process does not affect patients or healthcare professionals, it can be done in their presence and has a continuous, controllable effect. Photocatalytic paint in combination with a prototype luminaire with a precise spectrum light sources, light output and a light intensity distribution curve relative to the shape and dimensions of the rooms, shows that the proposed method may represent a successful alternative to classical methods of disinfection in hospitals. This technique can also be used in other areas of interest.