In a world first, Australian agricultural scientists have created a map that pinpoints global hotspots of glyphosate contamination.

Key points: The European Commission is still deciding whether to ban the use of Roundup

The European Commission is still deciding whether to ban the use of Roundup In Australia and overseas, there are multiple legal cases underway over claims that Roundup causes cancer

In Australia and overseas, there are multiple legal cases underway over claims that Roundup causes cancer Researchers, who have mapped where glyphosate has been used, say "it's found nearly everywhere globally" but have identified hotspots

Glyphosate is the active ingredient in weedkiller Roundup, originally produced by Monsanto — a global company now owned by Bayer.

The map identifies environmental risk analysis and determines that Australia's most affected regions are south-east New South Wales and central-west New South Wales continuing up to north-west Queensland.

Western Australia also shows various regions to have a medium hazard, as well as parts of South Australia and Victoria.

Lead author of the paper, Associate Professor Federico Maggi from the Sydney Institute of Agriculture, said the map was based on research complied over years of global study.

"The reason we produced the database is because there is a lack of understanding of the molecules used and the geographic distribution of the users," he said.

This comes as international agencies discuss the future of the herbicide.

"The European Commission is investigating whether to extend [Roundup's] licence, suspend the use of it, or ban it," Dr Maggi said.

In Australia and overseas, there are multiple legal actions underway against agricultural chemical company Monsanto over claims that Roundup causes cancer.

But Dr Maggi said the jury was still out on whether the chemical was a health risk.

"The scientific literature is very much divided into those who bring evidence that it may have negative impacts, and those who state there are no visible impacts on human health," he said.

'It's everywhere'

The research found that glyphosate and associated by-products of the chemical were detected in the majority of the globe's soil.

"It's found nearly everywhere globally, and it is unpreventable because we found that environments that have not been exposed to this molecule before have a very low capability to degrade it," Dr Maggi said.

"All croplands globally are currently affected by these substances; the intensity of the chemical is variable," he said.

But Dr Maggi said some countries had contamination at a much more hazardous level.

A Federal Court in San Francisco has concluded that a weedkiller containing glyphosate was a substantial factor in a California man's cancer. ( AP: Haven Daley )

"What we call the 'hotspots' are Europe, China, South-East Asia, North America, a little bit in South America, and Australia," he said.

Dr Maggi said the by-product of glyphosate, aminomethylphosphonic acid (AMPA), could pose more of a risk as it did not appear to break down, and the effects on environmental and human health were unknown.

"It's poisonous to plants, at least, and we don't know much about this molecule," he said.

Dr Maggie said the prevalence of the chemical was mostly found in soybean and corn pastures.

"Given the amount of glyphosate used globally, it's very likely that we will find this by-product molecule widely in the environment," he said.

Glyphosate contamination in Australia. ( Supplied: University of Sydney )

The director of the Sydney Institute of Agriculture, Professor Alex McBratney, said there had long been localised data and anecdotal evidence of glyphosate contamination.

"We often hear general statements about how much is being used, but this [map] allows us to see exactly where things are being used," Dr McBratney said.

"Although we think glyphosate is environmentally friendly, there are some residues from it that are building up in the soil — and we're not sure about whether [those residues] have any environmental consequences.

"I'm certainly concerned that there are effects from using large amounts of glyphosate, and we have developed our food system to use large amounts of glyphosate."

'Roundup resistance growing'

Dr McBratney said the Australian agriculture industry needed to ramp up efforts to implement alternative weed control tactics.

"We are concerned that, from a purely ecological point of view, having the world's food supply dependant on the use of this single herbicide is a fairly dangerous route to go down," he said.

"We do need to have three or four different alternatives to glyphosate, not because it's necessarily unsafe environmentally but there is herbicide resistance growing.

"Crops can actually tolerate glyphosate as a way of weed management, which encourages the overuse of the herbicide when we have other technologies available."

The world's first populations of glyphosate-resistant radish have been confirmed by Australian Herbicide Resistance Initiative researcher Mike Ashworth. ( Supplied: Grains Research and Development Corporation )

But Dr McBratney said, although 'red flags' were beginning to emerge, the relatively cheap price and ease of application made transitioning away from the product difficult.

"It's a little bit precarious to be relying on one single herbicide, and the sooner we can have alternatives out there in the field the better," he said.

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"The irony is that it allows us to do the agriculture that we strive to do, to preserve water and carbon, but by doing that we put ourselves in another danger — more of an ecological one.

"I think people have done it for the right reasons — both economically and environmentally — but the consequences might not be what we expect if we don't diversify soon."

Consumer acceptance fading

As customers became increasingly aware of what food they were consuming, Dr McBratney said farmers needed to move away from pesticides and herbicides.

"The biggest danger is the loss of public confidence in using this for the production of food," he said.

"Social licence for herbicides and pesticides is fading and we need to look at alternatives.

"I just feel that the environmental and the [ongoing] litigations will see glyphosate eventually not being used."

Demonstrators participate in a protest march against Monsanto in Paris in 2015. ( Reuters: Mal Langsdon )

Dr McBratney said the answer was likely to lie in high-tech machinery and the use of artificial intelligence.

"There are several people working on that in Australia, and I see that as the future for dealing with weeds in our agriculture," he said.

"Whether by modifying the crops themselves, or using more information-based technologies to detect weeds.

"Once you detect the weed you can electrocute it, steam it, or pull it out, so there are other ways of dealing with this problem."