SCREENING FOR INDOOR AIR QUALITY EXPRESS ASSESSMENT PROTOCOL OF AIR-CONDITIONED OFFICES

A successful Indoor Air Quality (IAQ) surveillance plan is essential for healthy and safe workplaces;yet it is costly to sample all air pollutants of the entire community. In Hong Kong, a voluntary IAQcertification scheme for workplaces proposes the acceptable concentration levels of nine commonindoor air pollutants, namely carbon dioxide (CO2), carbon monoxide (CO), respirable suspendedparticulates (RSP), nitrogen dioxide (NO2), ozone (O3), formaldehyde (HCHO), total volatile organiccompounds (TVOC), radon (Rn) and airborne bacteria count (ABC). However, technical difficultieshave been reported during the full assessment of these pollutants. This study hence investigates thefeasibility of a preliminary screening process for presumptive detection of IAQ problems in an airconditionedenvironment. Specifically, a simple screening test at certain probability of unsatisfactoryIAQ for air-conditioned offices, together with an IAQ index which employs the average fractional doseto certain exposure limits of a few most representative air pollutants (rather than all of the listed nine)was proposed. This is an alternative for routine inspection in determining the asymptomatic IAQunsatisfactory for some air-conditioned offices of Hong Kong. And it was evaluated in terms of the testsensitivity, specificity and predictive values. The screening test would be a useful tool for policymakers,building owners and professionals to identify offices with probable IAQ problems and to makedecisions on resources for efficient mitigation actions.