Top neurologists say they were snubbed in review of controversial weed killer

Neurologist David Blacker is calling on the Australian regulator to ban the herbicide paraquat. (Supplied) Leading neurologists say Australia's chemical regulator did not engage with expert submissions raising concerns about paraquat's links to Parkinson's disease. The Australian Pesticides and Veterinary Medicines Authority (APVMA) maintains that health and safety are its central consideration. The APVMA's review of paraquat has been underway since 1997 and a final decision is expected mid-year. Link copiedShareShare articleAustralia's top neurologists say they have been ignored by the chemical regulator as it considers the future of a controversial weed killer linked to Parkinson's disease. Dozens of the country's top movement disorder specialists say the Australian Pesticides and Veterinary Medicines Authority (APVMA) failed to engage with them during its review. It has raised fears that "real-world data" on paraquat's link to Parkinson's disease is being overlooked. It comes as a final regulatory decision on the herbicide is expected mid-year. Associate professor Wesley Thevathasan, a movement disorders specialist, said he and other experts had made submissions to the regulator during the public consultation process, but had received no further contact. Dr Wesley Thevathasan, a neurologist based in Melbourne, has treated thousands of patients with Parkinson's disease and says farmers are overly represented. (ABC News: Charlotte King) Dr Thevathasan is a Parkinson's disease specialist, and works across several hospitals, the University of Melbourne and The Florey Institute. "We put in submissions, myself, other scientific bodies, groups of neurologists, some of the leading scientific minds and organisations in Australia who have interest in Parkinson's disease, and as far as I know, none of us have been contacted by the APVMA." Paraquat and the related herbicide diquat are fast-acting weed killers that farming groups say are essential for controlling resistant weeds. The chemicals have been under review by the APVMA since 1997, and they are banned in the EU, the UK and China due to their toxicity. In its 2024 proposed regulatory decision the APVMA said "the available epidemiology data is insufficient to conclude any association between paraquat exposure and neurotoxicity (including Parkinson's disease) in the occupational environment." It's a position that Dr Thevathasan said conflicted with the "global consensus" in his field that exposure to paraquat was closely linked to the later development of Parkinson's disease. He said the evidence base used by the APVMA to date gave "almost no weight" to recent human studies. Parkinson's disease is a progressive, incurable neurological condition that affects movement and can cause stiffness and uncontrollable shaking. In this small rural community, Parkinson's disease is all too common. Many fear that farm chemicals could be behind it. Dr Thevathasan is not the only expert to raise concerns. More than 70 medical experts and clinicians from major hospitals, research institutes and movement disorder clinics around Australia have also put their names to submissions highlighting evidence linking paraquat to Parkinson's disease. "The suggestion that unless we can prove a link, it's considered safe rather than showing a degree of safety as we would for other significant exposures such as medications is always of concern, said neurologist Dr Kelly Bertram, president of the Movement Disorder Society of Australia and New Zealand. "Other jurisdictions around the world have seen the same level of data and have made a very different decision, which is not just to restrict the use but actually ban the sale of paraquat in the country," Dr Bertram said. The APVMA did not answer specific questions sent by the ABC, but in a statement said it acknowledged the "concerns of an association between paraquat exposure and Parkinson's disease," and that health and safety "is the central consideration". The regulator has confirmed to the ABC it has entered into a nine-month contract costing $109,000 with GRACosway, a public relations company that describes itself as a specialising in crisis communications. "As the independent regulator, the APVMA must follow a rigorous statutory process and is unable to pre-empt or release the findings of final decisions before they are formally published," the APVMA said in a statement. A spokesperson for Assistant Minister for Agriculture Anthony Chisholm said "the APVMA is using the full suite of its regulatory powers to promptly finalise long-standing chemical reviews". "Australians can have confidence that APVMA decisions are based on the best available science to improve health and safety outcomes for people, animals, and the environment," they said. According to the World Health Organization's (WHO) Global Burden of Disease study, Parkinson's disease is "the fastest-growing neurological disorder in the world in terms of

Top neurologists say they were snubbed in review of controversial weed killer

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