Background: Indoor air pollution contains several substances and can emanate from a range of sources. Of particular importance are volatile organic compounds (VOCs) and respirable particulates. The exposure to indoor air pollution can induce a wide range of acute and chronic respiratory health effects.

Objective: To investigate respiratory health effects of occupants in air-conditioned offices and to determine factors influencing their respiratory health.

Materials and Methods: Fourteen air-conditioned offices in Bangkok were measured for volume and concentration of PM2.5 and VOC. The 212 occupants in these offices were surveyed and their lung function were tested. The subjective respiratory symptoms were cough, phlegm, wheezing, and short breathing.

Results: The logistic regression analysis showed the concentration of VOC was significantly associated with forced vital capacity (FVC) and wheeze symptoms (p<0.05). Concentration of PM2.5 was significantly associated with the forced expiratory volume in the first second (FEV1) over the FVC (p<0.05). Smoking was significantly associated with cough (p<0.05). The significant association between history in gas or VOC job, and phlegm, current work experience, and FEV1 over the FVC ratio were found.

Conclusion: Indoor air pollution exposure was associated with respiratory health effects. Smoking and work experience also affect the respiratory health.

Keywords: Lung function, Respiratory health symptoms, Air-conditioned office

Received 16 Nov 2018 | Revised 18 Feb 2019 | Accepted 22 Feb 2019