Concerns are being raised over the potential use of two banned pesticides in the poisoning of about 30 magpies.
The native Australian birds were taken to a Cootamundra vet in September in various states of paralysis and weakness, with nine eventually dying.
The dead birds were taken for testing by the Environment Protection Authority (EPA), which found trace amounts of the banned chemicals DDE and dieldrin in their systems.
The EPA said the tests were “inconclusive” and that it could not confirm “whether the birds died from a poisoning incident or from naturally occurring diseases”.
Several magpies from Cootamundra were brought to a vet after showing signs of paralysis and weakness. (Supplied: Cooper Street Veterinary Hospital)
Banned substances
It has been illegal to use DDE or dieldrin in Australia for decades.
They belong to a group known as organochlorines, which are human-made chemicals once used widely as insecticides and pesticides.
DDE is a breakdown product of DDT, which Charles Sturt University associate professor Melanie Massaro said was used to fight malaria.
“DDT was used prolifically in various countries to effectively kill mosquitoes, which transmit malaria,” Dr Massaro said.
But Dr Massaro said by the 1970s “it became apparent that DDT has all sorts of negative effects.”
“Especially with birds of prey … their egg shells would be extremely thin and they were dying quite frequently,” she said.
Charles Sturt University associate professor Melanie Massaro. (Supplied: Charles Sturt University)
DDT was banned in the United States in 1972 and declared illegal to use in Australia in 1987.
The World Health Organisation’s website says dieldrin is highly toxic, which has led to humans being poisoned and can affect the central nervous system.
In 1987, the federal government restricted the use of dieldrin before banning it altogether in 1994.
“Both of these organochlorides are not good for our animals and humans because they are fat soluble,” Dr Massaro said.
“That means they accumulate … in animals rather than [being excreted].”
Possibility pesticides stockpiled
NSW Greens MP Sue Higginson said it was possible the chemicals were still being stored on people’s properties.
“It would be unbelievably concerning if that was the case,” she said.
“If it’s people still accessing or having these chemicals and using them, that would be catastrophic.
“We know that the life cycle and the life span of these chemicals is very long, it can range from months to years and, in many cases, decades.”
Greens MP Sue Higginson says the detection of two banned pesticides is a “wake-up call”. (ABC News: Nick Dole)
Ms Higginson said there was also a “bio-accumulative problem” where chemicals remained in the environment long after they were banned.
The use of banned chemicals can result in fines of up to $500,000 for an individual and $2 million for a corporation.
Banned pesticides regulated by EPA
The magpie deaths have sparked calls for stricter scrutiny of the use of banned chemicals.
“I think this is a real wake-up call to us. We don’t know what chemicals are in the environment; we don’t know what chemicals are being used,” Ms Higginson said.
“A system of regulation is failing.”
The magpies were taken to a local vet after showing signs of paralysis and weakness. (Supplied: Cooper Street Veterinary Hospital)
The Australian Pesticides and Veterinary Medicines Authority (APVMA) said in a statement: “States and territories are responsible for regulating the use of agricultural and veterinary chemicals after they’re sold.”
In NSW that responsibility falls to the EPA, which has declined ABC requests for an interview.
Cootamundra Mayor Abb McAlister said the government should “do something about calling these pesticides in”.
“Birds are a part of our life and our nature, and we want them to live the life span they are meant to live,” Cr McAlister said.
NSW Agriculture Minister Tara Moriarty was unavailable for an interview.
Cootamundra-Gundagai Mayor Abb McAlister says it’s concerning that some people may still be using banned pesticides. (ABC Riverina: Emily Doak)
