What are dioxins?
Dioxins are chemicals produced when household and industrial waste is burned and as by-products from some industrial chemical processes.
They persist in the environment for a long time and can get into food but assessments show the amounts are tiny so the risk to our health is minimal. Dioxins also break down in our bodies and we excrete them.
Where do dioxins come from?
More than 96 per cent of dioxins in the environment come from air emissions. Dioxins then fall to the ground and occur in trace amounts on soil, plant and water surfaces. In Australia, the major sources of dioxin emissions in the air are bushfires and burning agricultural stubble.
Plants do not generally absorb dioxins. However, dioxins can enter the food chain when animals eat plants on which dioxins have fallen. In oceans, rivers and lakes, filter-feeding animals can absorb dioxins when they filter sediments floating in the water.
What is being done to reduce dioxins in Australian food?
Although levels of dioxins in Australian food are low, the Australian Government has recognised it is important that we continue to reduce the amount of dioxins released into the environment, therefore further reducing their accumulation in the food chain. In 2001 the Australian Government funded a four year National Dioxins Program, implemented by the then Department of the Environment and Heritage. This program is now complete but the information it gathered is still relevant and is available on the department's website.
Dioxins in Sydney Harbour seafood
FSANZ and the NSW Food Authority have worked together since 2005 to assess the potential adverse health effects from dioxins in seafood caught in Sydney Harbour and found the risks to be very low, given that the general population only eats Sydney Harbour seafood infrequently and in small amounts. However, seafood caught in some areas of the harbour should not be eaten. See the FSANZ report (pdf 1mb) and the NSW Food Authority advice on eating seafood from Sydney Harbour.
Assessments carried out by FSANZ and the Department of Health show the risk to Australians from dioxins in food is very low.