tourists favor to spend their time in shopping malls in Hong Kong. Good indoor air quality is, therefore, very
essential to shoppers. In order to characterize the indoor air quality in shopping malls, nine shopping malls in Hong
?. ?. Kong were selected for this study. The indoor air pollutants included carbon dioxide CO , carbon monoxide CO , 2
?. ?. ?. total hydrocarbons THC , formaldehyde HCHO , respirable particulate matter PM and total bacteria count 10
?. TBC . More than 40% of the shopping malls had 1-h average CO levels above the 1000 ppm of the ASHRAE 2
standard on both weekdays and weekends. Also, they had average weekday PM concentrations that exceeded the 10
?. 3 Hong Kong Indoor Air Quality Objective HKIAQO . The highest indoor PM level at a mall was 380 gm . Of 10
the malls surveyed, 30% had indoor airborne bacteria levels above 1000 cfum3 set by the HKIAQO. The elevated
indoor CO and bacteria levels could result from high occupancy combined with insufficient ventilation. The 2
increased PM levels could be probably attributed to illegal smoking inside these establishments. In comparison, the 10
shopping malls that contained internal public transport drop-off areas, where vehicles were parked with idling
engines and had major entry doors close to heavy traffic roads had higher CO and PM indoor levels. In addition, 10<
