Toxic air pollutants are substances that generally exist at low concentrations in the ambient environment. They are of particular concern because their health effects are typically harmful or even carcinogenic in nature. Inhalation of sufficient levels of these pollutants can cause health problems such as cancer, reproductive disorders and lung damage.

The objective of the survey is therefore to provide information related to the roadside concentrations of selected Toxic Air Pollutants, to supplement the database on ambient levels of TAP, and incorporate the results into the SUSDEV21 baseline database.

The toxic air monitoring was carried out jointly by ERM and PolyU Technology and Consultancy Company Ltd (HKPU). The Desert Research Institute (DRI), Nevada, USA was contracted by HKPU for sample analysis. The survey involved field sampling and analysis of three different type of TAPs which are VOCs, carbonyl compounds and PAHs.

The components of this study performed by ERM are as follows:

• carrying out the management, co-ordination and planning for the TAP survey, as well as providing all necessary support, guidance and supervision to the non-professional components, liaising with relevant parties and reporting to the ESMG. In particular, a key element was the planning and supervising of the toxic air monitoring at a roadside monitoring station over the year; and

• carrying out analysis of the monitoring data collected, documenting and reporting the results.

The work carried out by HKPU together with DRI included:

• providing the necessary equipment and setting up and removing the monitoring station;

• collecting and testing of samples, including appropriate quality control measures and maintaining relevant records; and

• production and presentation of sample testing results.