2.2 Project design for dioxin measurements
The EPA study measured concentrations of the 17 most toxic congeners (with chlorine atoms in the 2,3,7 and 8 positions) at three sites, chosen to reflect a range of distinct environments. These were:
- a rural background site-Siding Spring Observatory in central-western NSW
- a site in western Sydney representative of urban conditions-Westmead, approximating the geographical centre of the Sydney Metropolitan Area
- an urban site near an industrial source of dioxins-Warrawong, about 3 kilometres south-east of the steelworks at Port Kembla in Wollongong.
Sampling began in November 1998 and continued till April 2000, excluding three months in early 1999.
Collection and analysis followed the US EPA Method TO-9A. Air was drawn into a canister through a filter paper and both the contents of the canister and the filters were then analysed by gas chromatography/mass spectrometry. Air was sampled continuously for 12 days at Westmead and Warrawong. Because the readings at Siding Spring were so low and the test methodology requires a sample to be taken which can provide a detectable concentration, samples at that site were taken continuously over 24 days.
Page last updated: 26 February 2011