Australia’s pesticides regulator, the Australian Pesticides and Veterinary Medicines Authority (APVMA) has released its long-awaited regulatory review into paraquat, after public consultation and considering the latest data from the United States. As expected from the preliminary report in 2024, the review retains the use of paraquat.

However, standard maximum broadacre application rates have been slashed by 80% to reduce the risk of acute human toxicity and environmental risks to wildlife. Higher rates are permitted solely for technology-assisted spot spraying. Furthermore, the types of applications that are allowed are greatly restricted to improve safety. While paraquat is known as a Schedule 7 poison, most commentary has focused on potential links to Parkinson’s disease.

Parkinson’s disease is a devastating, progressive movement disorder. Over time, people develop muscle rigidity, become less able to move, experience tremors, and become unsteady on their feet. While agricultural workers have a higher risk of Parkinson’s, tying this to any specific chemical exposure has been elusive.

The APVMA has concluded that the weight of evidence does not show that paraquat exposure increases the risk of developing Parkinson's disease. This conclusion is certain to be controversial.

But it is warranted. Experimental animals exposed to paraquat through typical routes of exposure (inhalation, oral consumption) do not develop Parkinson’s. Industrial workers exposed to high levels of paraquat have not developed Parkinson’s. Systematic reviews of epidemiologic studies have failed to find a definitive link.

Regardless, the new exposure and application limits will improve human and environmental safety.

This is a very concerning decision for rural communities. We already know that Parkinson’s disease is more prevalent in rural and regional areas, and while the APVMA claims the causal link with paraquat has not been conclusively shown, it seems they have ignored submissions from experts in the field on the growing epidemiological evidence for this link.

In our research, we have found that this increased prevalence is also compounded by the low level of local services available for patients in rural and regional areas, such as specialists, physiotherapists and allied health professionals, meaning that many patients must travel long distances to access their care.

The recent announcement of the continued approval for the use of the herbicide paraquat by the Australian Pesticides and Veterinary Medicines Authority (APVMA) is a blow for the Parkinson's disease community in Australia, who have actively campaigned to bring Australia into line with countries that have banned the use of this chemical.

This is because there is strong evidence that exposure to paraquat, particularly over a period of time or high doses, increases risk for this common neurological disease. While there is as yet no definitive proof that paraquat causes Parkinson's disease, as this would be extremely hard to prove in humans, the evidence suggests it would be wise to err on the side of caution.

Decreasing exposure by wearing protective clothing or using alternative weed-control chemicals would appear to be wise until we have a better understanding of this risk. While the use of paraquat has not been banned in Australia, it will now be used under stricter controls, including at lower diseases, and this may decrease possible risks to the community.