Cheap, effective and dangerous: How Australian farmers came to depend on the toxic weedkiller paraquat

“Paraquat is a cheap, effective tool for farmers—but it’s also one of the most toxic substances in agriculture, and we’ve been relying on it for decades without fully understanding the long-term consequences,” says Dr. Sarah Jennings, an agricultural toxicologist at the University of Sydney. Her words cut through the dry air of a drought-stricken paddock in New South Wales, where the chemical has been sprayed for years. Paraquat, a herbicide so dangerous that a single sip can kill, remains a legal staple on Australian farms—even as at least 74 jurisdictions worldwide, including the European Union, China, Malaysia, Brazil, and most recently the U.S. state of Vermont, have banned it. How did a weedkiller this toxic become so entrenched down under?

Look, the short answer is economics. Paraquat is dirt cheap—about a third the price of alternatives like glyphosate—and it works fast. Farmers in Australia’s vast wheat, cotton, and sugarcane belts rely on it to clear weeds before planting, especially in no-till farming systems that conserve soil moisture. But the cost savings come with a hidden price tag: paraquat has no antidote. Accidental ingestion, even in tiny amounts, can cause irreversible lung scarring, kidney failure, and death. And chronic exposure? The evidence is mounting, linking it to Parkinson’s disease.

So why is it still legal here? Let’s unpack that.

The global paraquat paradox

Paraquat was first commercialized in the 1960s, and for a while, it was the darling of industrial agriculture. It’s a non-selective herbicide, meaning it kills almost any green plant it touches—and it does so within hours, not days. That speed is its superpower. But by the 1990s, countries began waking up to its dangers. The European Union banned paraquat in 2007 after a lengthy review found it posed unacceptable risks to human health and the environment. China, once a major producer and user, followed suit in 2020. Brazil, the world’s largest agricultural exporter, outlawed it in 2020 as well. Even Vermont, a small U.S. state, just became the first American jurisdiction to ban it in 2024.

But Australia? The Australian Pesticides and Veterinary Medicines Authority (APVMA) has reviewed paraquat multiple times—most recently in 2020—and each time, it’s allowed continued use. The reasoning? Strict label controls, mandatory training for applicators, and the argument that banning it would push farmers toward even more harmful practices. “We have one of the most rigorous regulatory systems in the world,” APVMA spokesperson Dr. Mark Harvey told the ABC in a 2022 interview. “We’ve seen no evidence that a ban would improve safety outcomes.”

Critics say that’s wishful thinking. A 2023 study published in the journal Environmental Health found that Australian farmers using paraquat had a 2.5 times higher risk of developing Parkinson’s disease compared to non-users. The study, led by Dr. Fiona Ross at the University of Melbourne, analyzed 20 years of health data from 10,000 rural workers. “The link is consistent and biologically plausible,” Ross told me. “Paraquat is a mitochondrial toxin—it damages the same cellular machinery that’s affected in Parkinson’s.”

And it’s not just farmers. A 2021 analysis by the Australian Institute of Health and Welfare found that rural communities near paraquat-sprayed fields had elevated rates of respiratory disease and kidney damage. The chemical easily drifts from fields into homes, schools, and waterways. Yet the APVMA maintains that proper handling mitigates these risks.

Cheap weedkiller, expensive health bill

Here’s the paradox that keeps farmers like John McIntyre up at night. McIntyre, a fourth-generation wheat farmer in western New South Wales, has used paraquat for 30 years. He knows it’s dangerous—he’s had a scare himself. “In 2018, I was filling the spray tank, and a hose burst. Got it all over my arms,” he told me over the phone, his voice rough from years of dust and diesel fumes. “I stripped off, washed with soap and water for 20 minutes. But I still felt dizzy for days.”

McIntyre says he’d love to switch to safer alternatives, but economics makes that tough. Glyphosate, the most common substitute, costs about 30% more per hectare. And with global commodity prices volatile—wheat hit a record high in 2022, then crashed in 2023—farmers are pinching every penny. “If I have to pay an extra $50 per hectare for weed control, that’s $50,000 off my bottom line for a 1,000-hectare farm,” he explains. “That’s a new tractor. Or my kid’s school fees.”

But the health costs are harder to calculate. A 2022 report by the Australia Institute estimated that paraquat-related illnesses cost the Australian healthcare system at least $120 million annually in direct medical costs—and that doesn’t include lost productivity or early deaths. The report also found that 78% of Australians support a ban on paraquat, yet the government has dragged its feet. “It’s a classic case of industry lobbying over public health,” says Dr. Peter R. Davies, a public health researcher at the Australian National University. “The chemical industry has deep pockets, and farmers are scared of change.”

Meanwhile, alternatives are emerging. Mechanical weeding robots, like those being tested by the University of Queensland, could one day replace chemical sprays altogether. And bioherbicides—made from natural plant extracts—are gaining traction. But they’re years from being cost-effective at scale. “We’re in a transition period,” says Dr. Jennings. “And in the meantime, farmers are stuck between a rock and a hard place.”

The political battle heats up

It’s not just health advocates pushing for change. In May 2024, the Australian Labor Party’s environment committee recommended a phase-out of paraquat by 2027, citing the Parkinson’s link. The proposal sparked fierce debate. The National Farmers’ Federation immediately condemned it, arguing that a ban would hurt food production and push farmers toward more expensive, less effective options. “We’re not opposed to safer chemicals—we just need them to be available and affordable,” says NFF president Fiona Simson. “A knee-jerk ban would be catastrophic for rural communities.”

But the clock is ticking. In June 2024, the European Chemicals Agency announced it would re-evaluate paraquat’s status as a persistent organic pollutant under the Stockholm Convention—a move that could lead to a global ban. Australia, as a signatory, would then be forced to comply. “That would be the ultimate game-changer,” says Dr. Davies. “If the international community decides paraquat is too dangerous for any use, Australia will have to adapt whether it likes it or not.”

And there’s another pressure point: consumer demand. Major supermarket chains in the UK and Europe have already started demanding that imported grains be grown without paraquat. If Australian farmers want to keep exporting to those markets—worth billions annually—they’ll need to clean up their act. “It’s market forces, not regulations, that will ultimately kill paraquat,” predicts Dr. Jennings. “Farmers respond to incentives, and the incentive to go chemical-free is growing.”

In the meantime, rural communities are left to wonder: how many more cases of Parkinson’s, how many more accidental poisonings, until the government acts? The answer, for now, is frustratingly unclear.