The prevalence of allergic rhinitis in office worker and airborne fungi in the building with heating, ventilation, and air conditioning system

ABSTRACT

Purpose: The purpose of this study was to examine the prevalence of allergic rhinitis in office workers and that in the workplace in 1 large building which had close system and used Heating, Ventilation, and Air Conditioning system (HVAC system) and had the problem of visible mold and water intrusion. And, this study also aimed at studying the amount of airborne fungi and environmental factors that involved the airborne fungi in the building.Methodology: The design of study was cross sectional study. The data were collected by distributing the questionnaires to 404 office workers during April to May 2008. The response rate was 68.56 percents. Of 253/404 office workers served as sample population who were suited with the study criteria.Results: The overall percentages of the prevalence of allergic rhinitis in office workers and that in the workplace within the past month were 49.21 and 9.25, respectively. Factors significantly related to allergic rhinitis in the workplace within a past month were previous history of asthma, visible mold in the workplace, and a carpet in the workplace (p \< .05). The office workers in the building with the above factors were two or more times of higher risk to have allergic rhinitis than the office workers who did not have those factors. Meanwhile, room survey for airborne fungi showed a median of 198 Colony Forming Unit (CFU)/m3 of mold (Interquartile range (IQR) = 170 CFU/m3). Carbon dioxide and relative humidity significantly associated with the amount of airborne fungi (p \< .05).Discussion: The prevalence of allergic rhinitis of the office workers in this building is higher than that of general people in Thailand. However, there are a few office workers who have allergic rhinitis in the workplace and this is not related to the amount of airborne fungi. The amount of airborne fungi mainly depends on carbon dioxide and relative humidity not on visible mold, water intrusion or stain, water condensation, or mold odor in the workplace.