Marlborough Express - Weekend Express
Use of weedkiller glyphosate?
But they say they also use the chemical to maintain safety in road transport corridors, to protect assets like kerb sides and help with ecological restoration projects.
Some local boards choose not to use it at all.
Auckland Council and Christchurch City Council last year backed away from proposals to expand their glyphosate use.
Auckland Council did so after alternative methods for killing weeds, such as hot water, plantbased herbicide and removal by hand, were found not to be as expensive as stated.
Christchurch City Council acted after opponents branded the plan ‘‘short-sighted’’, and environmental campaigners called for a reduction in spraying as a way of getting rid of weeds.
Wellington City Council said it currently didn’t have ‘‘suitable alternatives’’ to glyphosate, which it used to protect and maintain infrastructural assets, ensure public safety, and protect the natural environment from invasive or difficult-to-control weed species.
Nelson City Council said it was prioritising a review on its use of glyphosate, over ecological, economic and health concerns from some in the community.
The council – recently targeted by Extinction Rebellion protesters for its use of the weedkiller – said 49 per cent of the 441 litres of glyphosate concentrate it used in 2019 was on its parks. Seventeen per cent was used in roadside vegetation, 28 per cent on forestry, and 6 per cent on ecological restoration/ environmental weed control activities.
The council said it sought to minimise glyphosate use in parks through mulching, and techniques including handweeding.
IS GLYPHOSATE HARMING HUMANS AND THE ENVIRONMENT?
That is the multibillion-dollar question.
German conglomerate Bayer AG, which bought Monsanto in 2018, has committed over US$10 billion to settle a flood of US lawsuits alleging Roundup caused cancer.
The firm says decades of studies show glyphosate is safe for human use.
In New Zealand, toxicologist Dr Belinda Cridge, from the Institute of Environmental Science and Research, says all chemicals pose risks.
While the IARC found glyphosate had the potential to cause cancer, it did not assess the chances of that happening.
Glyphosate affects soil composition, but poses very low risk to human and animal health as it breaks down ‘‘reasonably quickly’’, based on factors including soil chemistry and rainfall, Cridge says.
She believes there is no evidence that it is unsafe for people to use if applied correctly, using protective gear while spraying, and not spraying in high winds.
But the Soil and Health Association of New Zealand says evidence that glyphosate has the potential to cause harm to people should be enough for it to be banned in public places and around waterways.
Its glyphosate spokesperson, Jodie Bruning, says research overseas shows glyphosate can last in soils for months.
Countries in Europe and elsewhere are moving away from using glyphosate where the public could be exposed, and New Zealand should do the same on a ‘‘precautionary principle’’.
She says the EPA never conducted a risk assessment of glyphosate to understand how it worked in the New Zealand environment.
‘‘Local councils need to take the initiative ... because they are responsible for protecting public health.’’
SHOULD GLYPHOSATE BE RECLASSIFIED?
University of canterbury toxicology professor ian shaw says glyphosate should be categorised as hazardous until proven otherwise.
Having recently reviewed the gamut of scientific papers on glyphosate, he says we don’t know enough about its long-term effects.
When glyphosate was licensed in the 1970s, it was seen as the ‘‘holy grail of pesticides’’, with no effects on humans and animals.
‘‘One of the important environmental aspects of it was that it was quickly removed from the environment. We now know that really isn’t true.’’
The risks to people from single spraying or exposure to glyphosate are very low, he says.
But the chemical is constantly leaching into the environment, binding to soils and sediment in rivers and streams, and breaking down to a compound about which we knew very little.
‘‘We don’t have enough data about glyphosate’s long-term effects to rule out that it might be a carcinogen, and to rule out that it might be affecting ecosystems in a long-term context.
‘‘We’ve got to sit down and do a proper study that gives a definitive result, rather than lots of bits and pieces from around the world, that confuse the picture.’’