Source Apportionment of Particulate Pollutants in Hong Kong by Receptor Modeling  

Project Title: Source Apportionment of Particulate Pollutants in Hong Kong by Receptor Modeling

Applicant: The Hong Kong University of Science and Technology

Total Approved Grant: $112,500

Duration: 01/09/96 to 31/05/97

Project Status/Remarks: Completed

Scope: To determine the sources of airborne particulate pollutants found in Hong Kong.

Summary of the Findings/Outcomes: An advanced algorithm called Positive Matrix Factorization (PMF) in receptor modeling was used to identify the sources of Respirable Suspended Particulates (RSP) in Hong Kong, based on the compositional data obtained from the Hong Kong Environmental Protection Department (HKEPD) in 1992 and 1993. Unlike conventional receptor modeling algorithm such as Factor Analysis (FA), PMF only generated non-negative source profiles. A total of 11 factors were identified as the sources of RSP In Hong Kong. They were secondary ammonium sulfate, organic vehicular emission, particulate bromide, marine aerosols after chloride loss, coal burning, vehicular emission / incineration, crystal elements, marine aerosols, secondary nitrate, fuel oil burning, and particulate copper. The compositional profiles of these factors were also developed. PMF gave better results than FA in its ability to identify more factors and produce source profiles with all positive compositions.

This study provided a rigorous analysis of the HKEPD data beyond what was currently available. It generated source profiles that were based entirely on local aerosol data and could be all physically interpreted because of the non-negative constraints in the PMF algorithm.