Poor indoor air quality is a major threat towards workers since the office or office-like environment is now the workplace for the majority of the workforce in Malaysia. Workers in office buildings frequently have unexplained work-related symptoms or combinations of symptoms but evidence suggests that microbial contamination plays a part. Ultraviolet germicidal irradiation lights with high efficiency particulate air filter (UV-HEPA) are recognized for eradicating biological contaminants and capturing particles in indoor environments. Here, the effectiveness of UV-HEPA purification unit was obtained in two selected workplaces i.e. laboratory of conservation and laboratory of natural resources. Results show that there exist significance difference (P<0.05) on indoor air quality between pre-installation and post-installations of UV-HEPA filter in both selected room. Furthermore, it shows that UV-HEPA filter is effective in removing indoor air pollutants and improves the air quality. The use of UVGI lights with HEPA filter resulted in significant reduction in the concentration of microbes and respirable particulates within the ventilation systems. Keywords:indoorairquality,microbes,respirableparticulates,UV-HEPApurificationunit
