The roadside TAP monitoring station was located at U core podium level of HKPU at 6m above and set back 8m from Hong Chong Road as shown in a campus map in Annex A. The site was characterised by typical "street-canyon" topography with high traffic volumes, in order to represent the typical urban setting of Hong Kong.

The site provided enough space for all the TAP monitoring equipment and an air-conditioned equipment shelter. An electricity supply for operating the TAP monitoring equipment as well as for the air-conditioning was provided to maintain the equipment in an operational state during the summer months. The site was also secured from possible tampering or vandalism.

The list of Category I and II Toxic Air Pollutants to be surveyed was agreed upon with EPD. Measurements of the ambient concentrations of the following species were undertaken at the roadside monitoring location:

• 1,3-Butadiene (Cat I);

• Benzene (Cat I);

• Formaldehyde (Cat I);

• Acetaldehyde (Cat II);

• Anthracene (Cat II);

• Methyl Chloride (Cat II);

• Benzo(a)anthracene (Cat II);

• Benzo(a)pyrene (Cat II);

• Chrysene (Cat II);

• Trichloroethylene (Cat II); and

• Tetrachloroethylene (Cat II).