Monitoring POPs in Australia - past, present and future

Jochen F. Müller

National Research Centre for Enviromental Toxicology

The University of Queensland

Monitoring of persistent organic pollutant is a major challenge. Most POPs occur in the environment at trace levels and the analytical costs, particularly for the most toxic POPs, the dioxin-like chemicals prohibits continuous large monitoring program particularly in large countries with relatively small populations such as Australia. Although selected POPs such as organochlorine pesticides have been included in routine monitoring efforts such as the National Residue Survey and the Food Basket studies a lack of funding and analytical capabilities have prevented the inclusion of dioxin-like chemicals in these surveys. In addition only very few other studies in Australia included monitoring of dioxin-like chemicals and until recently no systematic efforts have been made to evaluate exposure to dioxins in Australia.

Together with more than 150 countries Australia has signed the global treaty on POPs and the federal government is currently considering ratification of the treaty. This treaty - at least in part - has triggered a National Dioxin Program (NDP) that includes evaluation of the level of dioxin-like chemicals in the environment and humans. Phase 1 studies of the NDP which focused on the determination of background levels of dioxin-like chemicals in food, the environment and human are currently completed. These studies provide the first comprehensive evaluation of dioxin-like chemicals in Australia and will be used to carry out a risk assessment of these chemicals in Australia. The inclusion of a bushfire study (experimental evaluation of emission from bushfires) further accounts for the specific situation in Australia where previous estimates suggested that bushfires contribute to more than 70 % of the dioxin emissions in Australia.

Monitoring the risk from POPs requires understanding of the exposure and effects of these chemicals in combination with all other chemicals that are present. To account for the effects of mixed toxicity and to evaluate the combination of chemicals and their combined effects research is currently underway that combines novel time integrated extraction of chemicals and a toxicological profiling of the mixture using relevant assays that are associated with the toxicity of POPs. The development of these techniques aim to provide a cost-effective means for monitoring pollutants including POPs in the future.