| Like most of the developed countries and metro area in the world, people spent most of their lifetime working in the indoor environments with mechanically ventilation facilities. The human exposure on various air pollutants changed its importance in nature from the outdoor origin to indoor. While the indoor environment was actually a confined space where air pollutants might not be able to dilute itself or exhausted to the adjacent environment effectively, the indoor air quality could only be controlled by either source management or relied on the performance of the ventilation system. As some of the air pollution sources were basically originated from the building envelop that could not be removed or hard to mitigate, the remaining questions were how the indoor air quality be smartly monitored and how the information could be implemented for the system control to achieve the best air quality delivery. As indoor air pollutants were from various sources and with different nature, just to perform a representative measurement and label them with a representative standard guideline for health concern was considerably a difficult task.; In search of the problems and the possible mitigation measures, the Hong Kong Environmental Protection Department HKEPD conducted an extensive indoor air quality consultancy study in 1995. The objective of the study was to evaluate the existing IAQ condition in typical commercial buildings in Hong Kong and to establish a realistic guideline for the building related industry to comply. From the results of the study, it was observed that most of the building was under-ventilated and the accumulation of indoor air contaminants was common and worth further investigation to avoid any possible hazardous scenario. Based on the results, the HKEPD issued a draft document named “Guidance Note for the Management of Indoor Air Quality in Offices and Public Places” (GN) in 1997 for public comment. The GN illustrated the common indoor air pollutants and their nature suggested with appropriate measurement methods. In reference with some international air pollutants exposure limits, the GN introduced a classification of IAQ in offices and public places with respect to three levels objectives, where level 1 represented a prestigious environment, level 2 represents a health and well maintained environment and level 3 was an acceptable work place in the sense of occupational safety. (Abstract shortened by UMI.)... |
