2005
Department of the Environment and Heritage
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About the report
The term “dioxins” describes a group of toxic organic chemicals that remain in the environment for a long time. These compounds can accumulate in the body fat of animals and humans and tend to remain unchanged for long periods. Several hundred of these compounds exist and are members of three closely related families:
- the polychlorinated dibenzo–p–dioxins (PCDDs)
- the polychlorinated dibenzofurans (PCDFs or furans)
- certain co–planar polychlorinated biphenyls (PCBs).
The National Dioxins Program (NDP) has focused on the 29 most toxic of these compounds which are recognised internationally as being harmful to humans and animals. To assist the reader, the term “dioxins” is used in this report to refer to the three families, but there are instances where specific mention is made to furans and PCBs.
The Australian Government established the program in 2001 to improve knowledge about dioxins in Australia. The program aims to determine levels, assess the risks to Australians and our environment, and to consider appropriate management actions.
Previously, limited Australian studies showed environmental levels were low, but a lack of information made it difficult to assess dioxin impacts on the environment and human health. The current studies are designed to fill this gap.
Starting in mid 2001, information studies were undertaken by leading Australian scientific organisations, with assistance from overseas experts, under contract to the Australian Government Department of the Environment and Heritage. The studies gathered information by measuring, emissions from sources such as bushfires, as well as dioxin levels in the environment, food and population. The findings of these studies were used to determine the risk dioxins pose to our health and the environment.
Due to the high costs for laboratory analysis of dioxins, the number of samples collected for each study was limited and so caution is required when interpreting the findings. Nevertheless, these studies, completed in 2004, provide the largest survey of dioxin levels ever undertaken in Australia. This document summarises the results of these studies and the conclusions of the risk assessments.
The findings will contribute to debate on how to deal with dioxins in Australia, as well as assisting Australia meet its obligations under the Stockholm Convention on Persistent Organic Pollutants (POPs). The Convention sets out a range of obligations for countries to reduce and, where feasible, eliminate releases of persistent organic pollutants, including emissions of by–product POPs such as dioxins.