Sterilization Efficiency of the Photocatalyst against Environmental Microorganisms in a Health Care Facility

Abstract

The photocatalyst equipment consists of a titanium dioxide membrane and an ultraviolet lamp. The authors studied if the photocatalyst equipment is practically useful in sterilizing environmental microorganisms in the health care facility. The number of microorganisms was compared in the cases of no sterilization (control) and the photocatalyst sterilization. As a result, a statistical difference was observed between control and the photocatalyst sterilization against airborne microorganisms (p<0.01), but not against surface microorganisms (p>0.2). The photocatalyst uses an air sucking system, so it may be ineffective against microorgan isms tightly attached to surfaces. However, the effectiveness of the photocatalyst to sterilize airborne microorganisms in the health care facility was successfully confirmed. Concerning the humidity effect on the photocatalyst sterilization, the authors compared the number of airborne microorganisms in cases of the control, UV alone and photocatalyst sterilization when humidity was changed.A statistical difference was observed between UV and the photocatalyst sterilization (p<0.01) when humidity was increased to 60-70%, but not observed between UV and the photocatalyst sterilization (p>0.2) when humidity was not controlled and was around 10-20%. This indicates that maintaining high humidity levels will present satisfactory sterilization results due to a greater production of OH radicals. From data obtained, no effect of the adsorption on the TiO2 membrane could be observed.

Nanomaterials and nanoparticles: Sources and toxicity

“…[141][142][143][144][145] New research is exploring the potential use of nanostructured titanium dioxide photocatalyst materials for sterilizing equipment of environmental microorganisms in the health care facility. 146 Silver nanoparticles are used as antibacterial/antifungal agents in a diverse range of applications: air sanitizer sprays, socks, pillows, slippers, face masks, wet wipes, detergent, soap, shampoo, toothpaste, air filters, coatings of refrigerators, vacuum cleaners, washing machines, food storage containers, cellular phones, and even in liquid condoms.…”

Inactivation of Microorganisms and Endotoxins by Low Temperature Nitrogen Gas Plasma Exposure

“…The UV irradiation effect involved in this sterilization mechanism is presented in Figure la and 1b. The UV irradiation effect on microbicidal activity has been discussed by Shintani et al (2006). BI of G. stearothermophilus ATCC 7953 spores was used to confirm the sterility assurance as it indicated the most resistant species to plasma sterilization (Tamazawa, 2004;Kelly-Wintenberg et al, 1998).…”

Inactivation of Bacterial Spore, Endotoxin, Lipid A, Normal Prion and Abnormal Prion by Exposures to Several Sorts of Gases Plasma

“…Several studies have demonstrated that some of these microorganisms are resistant to antibiotics such as MRSA and VRE and so on http //www.betterhealth. vic.gov.au/bhcv2/bhcarticles.nsf/pages/Antibiotic_resis-ta nt_bacteria and have an impact on the patients Elixhauser and Steiner, 2007 this indicates the need for improved sterilization procedures to ensure medical products are free from bioburden, airborne falling microorganisms or adhesive microorganisms as far as possible Shintani et al, 2003Shintani et al, 2006Shintani, 2013Shintani, 2014 . However, some studies Lipscomb et al, 2006Lipscomb et al, , 2008 have shown that significant quantities of residues composed of salts, proteins and organic matter are left on surgical instruments even after complete cleaning and sterilization in sterile service departments SSDs .…”