The methodology used in this study was generally consistent with that applied at the two EPD TAP monitoring stations currently in operation, as specified in the EPD document, Ref PT/212/96, Supply, Installation, Establishment and Operation of 2 Toxic Air Pollutants Monitoring Stations - Notes for Tenderers. Utilisation of equivalent equipment and sampling methodology ensured direct comparability between the datasets. The monitoring station was operational for 12 months and throughout this period its operation , maintenance and the associated QA/QC programmes were equivalent to those implemented at the existing EPD TAP monitoring stations.