Recent Trends in Indoor Air Quality in Air-conditioned Office Buildings in Hong Kong: A Systematic Review

摘要

As it is too expensive to sample all air pollutants of a general community, air sampling should be conducted based on a practical assessment strategy and monitoring plan. In Hong Kong, the Environmental Protection Department (HKEPD) developed a set of Guidance Notes to grade indoor air quality (IAQ) in workplaces as 'Excellent' or 'Good'. IAQ is defined by measuring the levels of twelve indoor environmental parameters: carbon dioxide (CO_2), carbon monoxide (CO), respirable suspended particulates (RSP), nitrogen dioxide (NO_2), ozone (O_3), formaldehyde (HCHO), total volatile organic compounds (TVOC), radon (Rn), airborne bacteria count (ABC), temperature (T), relative humidity (RH) and air velocity (V). This study investigated, with assessment results based on Hong Kong indoor environments in the past decade, the implications of the Guidance Notes for indoor workplace environments in Hong Kong. In particular, recent assessment results of the twelve stated parameters at 422 offices are reported and used to identify recent trends of IAQ in Hong Kong air-conditioned office buildings. The predicted satisfactory rates of CO_2, HCHO and ABC were found enhanced with the implementation of the Guidance Notes from 1999 to 2003: they were improved from 28 to 82% and 56 to 97% for CO_2, from 16 to 42% and 72 to 94% for HCHO, and from 33 to 51% and 69 to 85% for ABC, all in the 'Excellent' and 'Good' levels respectively.