Abstract
OBJECTIVES: The indoor environment of modern office buildings represents a new ecosystem that has been created totally by humans. Bacteria and fungi may contaminate this indoor environment, including the ventilation systems themselves, which in turn may result in adverse health effects. The objectives of this study were to test whether installation and operation of germicidal ultraviolet (GUV) lights in central ventilation systems would be feasible, without adverse effects, undetected by building occupants, and effective in eliminating microbial contamination. METHODS: GUV lights were installed in the ventilation systems serving three floors of an office building, and were turned on and off during a total of four alternating 3 week blocks. Workers reported their environmental satisfaction, symptoms, as well as sickness absence, without knowledge of whether GUV lights were on or off. The indoor environment was measured in detail including airborne and surface bacteria and fungi. RESULTS: Airborne bacteria and fungi were not significantly different whether GUV lights were on or off, but were virtually eliminated from the surfaces of the ventilation system after 3 weeks of operation of GUV light. Of the other environmental variables measured, only total airborne particulates were significantly different under the two experimental conditions--higher with GUV lights on than off. Of 113 eligible workers, 104 (87%) participated; their environmental satisfaction ratings were not different whether GUV lights were on or off. Headache, difficulty concentrating, and eye irritation occurred less often with GUV lights on whereas skin rash or irritation was more common. Overall, the average number of work related symptoms reported was 1.1 with GUV lights off compared with 0.9 with GUV lights on. CONCLUSION: Installation and operation of GUV lights in central heating, ventilation and air conditioning systems of office buildings is feasible, cannot be detected by workers, and does not seem to result in any adverse effects.
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Selected References
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- Bernstein R. S., Sorenson W. G., Garabrant D., Reaux C., Treitman R. D. Exposures to respirable, airborne Penicillium from a contaminated ventilation system: clinical, environmental and epidemiological aspects. Am Ind Hyg Assoc J. 1983 Mar;44(3):161–169. doi: 10.1080/15298668391404581. [DOI] [PubMed] [Google Scholar]
- Burge P. S., Finnegan M., Horsfield N., Emery D., Austwick P., Davies P. S., Pickering C. A. Occupational asthma in a factory with a contaminated humidifier. Thorax. 1985 Apr;40(4):248–254. doi: 10.1136/thx.40.4.248. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harrison J., Pickering C. A., Faragher E. B., Austwick P. K., Little S. A., Lawton L. An investigation of the relationship between microbial and particulate indoor air pollution and the sick building syndrome. Respir Med. 1992 May;86(3):225–235. doi: 10.1016/s0954-6111(06)80060-0. [DOI] [PubMed] [Google Scholar]
- Hodgson M. The sick-building syndrome. Occup Med. 1995 Jan-Mar;10(1):167–175. [PubMed] [Google Scholar]
- Hugenholtz P., Fuerst J. A. Heterotrophic bacteria in an air-handling system. Appl Environ Microbiol. 1992 Dec;58(12):3914–3920. doi: 10.1128/aem.58.12.3914-3920.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Husman T. Health effects of indoor-air microorganisms. Scand J Work Environ Health. 1996 Feb;22(1):5–13. doi: 10.5271/sjweh.103. [DOI] [PubMed] [Google Scholar]
- Jaakkola J. J., Miettinen P. Type of ventilation system in office buildings and sick building syndrome. Am J Epidemiol. 1995 Apr 15;141(8):755–765. doi: 10.1093/oxfordjournals.aje.a117498. [DOI] [PubMed] [Google Scholar]
- Mendell M. J., Fisk W. J., Deddens J. A., Seavey W. G., Smith A. H., Smith D. F., Hodgson A. T., Daisey J. M., Goldman L. R. Elevated symptom prevalence associated with ventilation type in office buildings. Epidemiology. 1996 Nov;7(6):583–589. doi: 10.1097/00001648-199611000-00004. [DOI] [PubMed] [Google Scholar]
- Mendell M. J., Smith A. H. Consistent pattern of elevated symptoms in air-conditioned office buildings: a reanalysis of epidemiologic studies. Am J Public Health. 1990 Oct;80(10):1193–1199. doi: 10.2105/ajph.80.10.1193. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Menzies D., Bourbeau J. Building-related illnesses. N Engl J Med. 1997 Nov 20;337(21):1524–1531. doi: 10.1056/NEJM199711203372107. [DOI] [PubMed] [Google Scholar]
- Menzies D., Comtois P., Pasztor J., Nunes F., Hanley J. A. Aeroallergens and work-related respiratory symptoms among office workers. J Allergy Clin Immunol. 1998 Jan;101(1 Pt 1):38–44. doi: 10.1016/S0091-6749(98)70191-5. [DOI] [PubMed] [Google Scholar]
- Menzies R., Tamblyn R., Farant J. P., Hanley J., Nunes F., Tamblyn R. The effect of varying levels of outdoor-air supply on the symptoms of sick building syndrome. N Engl J Med. 1993 Mar 25;328(12):821–827. doi: 10.1056/NEJM199303253281201. [DOI] [PubMed] [Google Scholar]
- Neas L. M., Dockery D. W., Burge H., Koutrakis P., Speizer F. E. Fungus spores, air pollutants, and other determinants of peak expiratory flow rate in children. Am J Epidemiol. 1996 Apr 15;143(8):797–807. doi: 10.1093/oxfordjournals.aje.a008818. [DOI] [PubMed] [Google Scholar]
- O'Hollaren M. T., Yunginger J. W., Offord K. P., Somers M. J., O'Connell E. J., Ballard D. J., Sachs M. I. Exposure to an aeroallergen as a possible precipitating factor in respiratory arrest in young patients with asthma. N Engl J Med. 1991 Feb 7;324(6):359–363. doi: 10.1056/NEJM199102073240602. [DOI] [PubMed] [Google Scholar]
- Riley R. L., Knight M., Middlebrook G. Ultraviolet susceptibility of BCG and virulent tubercle bacilli. Am Rev Respir Dis. 1976 Apr;113(4):413–418. doi: 10.1164/arrd.1976.113.4.413. [DOI] [PubMed] [Google Scholar]
- Salvaggio J. E. Recent advances in pathogenesis of allergic alveolitis. Clin Exp Allergy. 1990 Mar;20(2):137–144. doi: 10.1111/j.1365-2222.1990.tb02658.x. [DOI] [PubMed] [Google Scholar]
- Salvaggio J., Aukrust L. Postgraduate course presentations. Mold-induced asthma. J Allergy Clin Immunol. 1981 Nov;68(5):327–346. doi: 10.1016/0091-6749(81)90131-7. [DOI] [PubMed] [Google Scholar]
- Samet J. M., Marbury M. C., Spengler J. D. Health effects and sources of indoor air pollution. Part II. Am Rev Respir Dis. 1988 Jan;137(1):221–242. doi: 10.1164/ajrccm/137.1.221. [DOI] [PubMed] [Google Scholar]
- Smoragiewicz W., Cossette B., Boutard A., Krzystyniak K. Trichothecene mycotoxins in the dust of ventilation systems in office buildings. Int Arch Occup Environ Health. 1993;65(2):113–117. doi: 10.1007/BF00405729. [DOI] [PubMed] [Google Scholar]
- Woodard E. D., Friedlander B., Lesher R. J., Font W., Kinsey R., Hearne F. T. Outbreak of hypersensitivity pneumonitis in an industrial setting. JAMA. 1988 Apr 1;259(13):1965–1969. [PubMed] [Google Scholar]
- Woods J. E. Cost avoidance and productivity in owning and operating buildings. Occup Med. 1989 Oct-Dec;4(4):753–770. [PubMed] [Google Scholar]