Abstract
Contamination of indoor air by microbial pollutants has been increasingly recognized as a public health problem, and may be responsible for building-related illness (BRI) and sick-building syndrome (SBS). Bioaerosols such as fungi, bacteria, and viruses in indoor air can cause allergic and irritant responses, infectious diseases, respiratory problems, and hypersensitivity reactions. People sensitive to indoor environmental problems complain of a wide variety of symptoms ranging from headache, fatigue, nausea, sinus congestion, to eye, nose, and throat irritations.
Although ultraviolet germicidal irradiation (UVGI) with a predominant wavelength of 254 nm has been used for air disinfection for many years to minimize microbial numbers in the air, few quantitative data are available on the radiation susceptibilities of individual airborne microbes. There have been a number of UVGI studies documenting the effectiveness of UVGI for the control of microbes in controlled settings. Many of these studies documented the effectiveness of UVGI against airborne tuberculosis organisms.
The studies described here used commercial type fan-powered shielded UVGI-containing fixtures to evaluate their effectiveness in air disinfection. Aerosolization tests were done in the contained environment of a negative pressure bioaerosol stainless steel testing chamber 0.75 m wide·3.7 m long. The chamber was designed so that microbes could be safely aerosolized and contained while traversing the chamber through the UVGI-containing fix-tures. Four commercial (Purair UV Germicidal Systems, Mount Vernon, N.Y.) fan-powered UVGI-containing fix-tures placed in the chamber were individually evaluated for their ability to disinfect individual bioaerosols of air-borne bacteria.
Air samples were taken at the inlet and outlet of the UVGI-containing units positioned in the bioaerosol chamber, using Ace Glass all-glass impingers (AGI-30). Five bacterial species were individually aerosolized to evaluate their kill. The bacteria used to test all of the UVGI-containing units were vegetative cells of Escherichia coli, Micrococcus luteus, Pseudomonas fluorescens, Staphylococcus aureus, and endospores of Bacillus subtilis. Based upon the concentration of bioaerosols collected at the inlet and outlet of the fixtures tested, the total overall microbial kills for the four fixtures with the filters in place and the UVGI units on were more than 99% for all the airborne vegetative bacteria tested, and a mean of over 75% for the B. subtilis endospores.
All of the fixtures were efficient in the kill of the test vegetative bacteria used, even the more UVGI-resistant M. luteus vegetative cells and endospores of B. subtilis. Units such as these may provide an economical way to supplement existing air cleaning procedures used in indoor environments, and to kill airborne bacteria effectively without human exposure to UV light.
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References
Aksenov SV, Krasavin EA, Litvin AA (1997) Mathematical model of the SOS response regulation of an excision repair deficient mutant of E. coli after ultraviolet light irradiation. J Theor Biol 186:251–260
Balows A (1992) The Prokaryotes: a handbook on the biology of bacteria: ecophysiology, isolation, identification, applications, Vols 1–4. Springer, Berlin Heidelberg New York
Centers for Disease Control and Prevention (1994) Guidelines for preventing the transmission of Mycobacterium tuberculosis in health care facilities. MMWR 43 (No. RR-13), 132 pp
Centers for Disease Control and Prevention (1982) Guidelines for the prevention of tuberculosis transmission in hospitals. CDC, DHHS publication no. (CDC) 82-8371
Clark S, Scarpino PV (1996) Disinfection of microbial aerosols. In: Hurst CJ (ed) Modeling disease transmission and its prevention by disinfection. Cambridge University Press, Cambridge
Gherna R et al (eds) (1992) American type culture catalogue of bacteria and phages, 18th edn. ATCC, Rockville, Md.
Howard PA, Cancio LC, Mcanus AT, Goodwin CW, Kim SH, Pruitt Jr BA (1999) What’s new in burn associated infections? Curr Surg 56:397–405
Laboratory Center for Disease Control-Health Protection Branch (1996) Guidelines for preventing the transmission of tuberculosis in Canadian health care facilities and other institutional settings. Canada Communicable Disease Report 22S1. Homepage. www.hc-sc.gc.ca/hpb/lcdc/publicat/tbguide
Macher JM (1993) The use of germicidal lamps to control tuberculosis in healthcare facilities. Infec Control Hosp Epidemiol 14:723–729
Macher JM, Aleantils LE, Chang YL, Lin KS (1992) Effect of ultraviolet germicidal lamps on airborne microorganisms in an outpatient waiting room. J Appl Occup Environ Hyg 7:505–513
Marthi B, Fieland VP, Walter M, Seidler RJ (1990) Survival of bacteria during aerosolization. Appl Environ Microbiol 56:3463–3467
Miller SL, Macher JM (2000) Evaluation of a methodology for quantifying the effect of room air ultraviolet germicidal irradiation on airborne bacteria. Aerosol Sci Technol 33:274–295
National Institute for Occupational Safety and Health (1972) Criteria for a recommended standard occupational exposure to ultraviolet radiation. Department of Health and Human Services, Cincinnati, Ohio, Publication no. HSM 73-11009
Nicas M, Miller SL (1999) A multi-zone model evaluation of the efficacy of upper-room air ultraviolet germicidal irradiation. Appl Environ Occupational Hyg J 30:317–328
Riley RL, NordellEA (1992) Clearing the air: the theory and application of ultraviolet air disinfection. Am Rev Respir Dis 139:1286–1294
Riley RL, Knight M, Middlebrook G (1976) Ultraviolet susceptibility of BCG and virulent tubercle bacilli. Am Rev Respir Dis 113:413–418
Riley RL, Mills CC, O’Grady F, Sultan LU, Wittstadt F, Shivpuri DV (1962) Infectiousness of air from a tuberculosis ward. Am Rev Respir Dis 85:511–525
Riley RL, O’Grady F (1961) Airborne infection. Macmillan, New York
Salie F, Scarpino PV, Clark S, Willeke K (1995) Laboratory evaluation of airborne microbial reduction by an ultraviolet light positioned in a modified hollow ceiling fan blade. Am Ind Hyg Assoc J 56:987–992
Scarpino PV, Jensen NJ, Jensen PA, Ward R (1998) The use of ultraviolet germicidal irradiation (UVGI) in disinfection of airborne bacteria and rhinoviruses. J Aerosol Sci 21:S777–S778
Scarpino PV, Quinn H (1998) Bioaerosol distribution patterns adjacent to two swine-growing-finishing housed confinement units in the American Midwest. J Aerosol Sci 29:S553–S554
Schwartz T (1998) UV light affects cell membrane and cytoplasmic targets. J Photochem Photobiol B: Biol 44:91–96
Sneath PHA (ed) (1986) Bergey’s manual of systematic bacteriology, Vols 1–3. Williams and Wilkins, Baltimore Md.
Suter B, Livingstone-Zatchej M, Meier A, Thoma F (1997) Chromatin structure and transcription affect repair of cyclobutane pyrimidine dimers and photolase. Mutation Res 379:S42
Wallace BM, Lasker JS (1992) Awakenings … UV light and HIV gene activation. Science 257:1211–1212
Wesley C (1996) Evaluation of UV energy and ozone emissions from Purair UV germicidal systems. Galson Corporation report on Project No. 964082
Wurtz R, Karajovic M, Dacuos E, Jovanovic B, Hanumadass M (1995) Nonsocoial infections in a burn intensive care unit. Burns 21:181–18
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Green, C.F., Scarpino, P.V. The use of ultraviolet germicidal irradiation (UVGI) in disinfection of airborne bacteria. Environmental Engineering and Policy 3, 101–107 (2001). https://doi.org/10.1007/s100220100046
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DOI: https://doi.org/10.1007/s100220100046