Hong Kong is one of the most densely populated cities in the world with over 7 million population living in the territory of 1,106 km2. The well-developed roadway transport network in Hong Kong also faces issues of narrow and congested roads with tall buildings forming street canyons that effectively trap the traffic pollutants and elevate the pollution level inside the streets.
Currently, the only publicly available air quality information source is from the government Air Quality Monitoring Stations (AQMS) operated by Hong Kong Environmental Protection Department (HKEPD) that measure the pollutant concentration at different districts in Hong Kong. However, these fixed air stations failed to represent the actual public exposure since the individuals may experience a wide variety of outdoor locations and indoor environments in a day by themselves, and different homes, offices and commute modes also have varying levels of pollutants. The mismatch of information creates the uncertainty to evaluate the population exposure and the gaps of individual’s expectations to understand and mitigate their own air exposure related health risks. There is no doubt a better understanding of individual’s exposure in different environments helps to identify the source, activity or microenvironment that contribute the significant health risks, and enact effective mitigation measures for determinants of exposure.
This study represents the first attempt of real-world monitoring of personal air pollution exposure by a uniform population group who are the volunteers working in International Commerce Centre (ICC) in West Kowloon, Hong Kong. We developed and employed portable sensor package to monitor the air pollutant PM2.5 exposure profiles of the volunteer groups who work in the same office environment but reside in different districts and travel by different commute modes. Over 70 volunteers have participated in the study by carrying the personal exposure kits (PEKs) to monitor their personal time activities and surrounding air quality. A total of 111 weekday and 50 weekend complete profiles were collected and analysed.
The outcomes of this study are expected to improve our understanding on the relation between the individual time activity and exposure risk, the contribution of different outdoor and indoor microenvironments to the integrated exposure for Hong Kong residents. The active engagement of the volunteers offered a new opportunity to raise the environmental awareness of the general public to understand and mitigate their individual exposure health risks.