THE OCCURRENCE, DISTRIBUTION AND SOURCES OF POLYCYCLIC AROMATIC-HYDROCARBONS IN THE SEDIMENTS OF THE GEORGES RIVER ESTUARY, AUSTRALIA

Concentrations of 13 polycylic aromatic hydrocarbons (PAH) in sediment samples from the Georges River estuary N.S.W. have been determined by gas chromatography/mass spectrometry (GC-MS). The concentrations of individual PAH were in the range of <0.1-5600 mug kg-1 dry weight. The average values of PAH (11-1300 mug kg-1 dry weight) are well above those previously found in other industralized urban areas of Australia. The highest total PAH concentrations in sediments are found in a section of the river which also has the highest concentrations of silt, clay and organic matter, indicating that the PAH distribution may be controlled by sedimentation processes. Examination of the alkylated and non-alkylated PAH distributions in sediment extracts suggested that the main source of PAH is from combustion products, possibly associated with air particles, with point source contributions of two ring PAH from marinas and other boating activities at some sites.