Risk from herbicides too great

22:47, Jul 14 2014

New Zealand farmers could be setting themselves up for market rejection of their primary products through continued reliance on glyphosate as a management tool.

The more I investigate the product, the more I am concerned about its long-term effectiveness because emerging research indicates serious problems.

Glyphosate resistance is emerging in New Zealand production, including in our vineyards, according to the Foundation For Arable Research. And scientific research from overseas is flagging connections between disease and illness and the international plantings of herbicide-tolerant crops that follows with the consumption of the food from these plants.

Distributors and manufacturers of glyphosate promote its rapid breakdown in soil, and that it is excreted in our urine and therefore is non bio-accumulative. However, a US pilot study released by Sustainable Pulse in April this year shows it was in human breast milk at up to 1600 times higher than the European Drinking Water Directive allows for individual pesticides.

The test commissioners have asked the USDA and EPA to halt its use until further tests are completed.

Emerging research by University of Caen molecular biologist Giles-Eric Seralini indicates the more harmful substance may not be the glyphosate but an adjuvant which is recorded as actively toxic to human cells. Adjuvants stabilise the compounds in glyphosate and assist with spray penetration.


For years health and environmental assessors have tested glyphosate itself for its effects on mammals, but not in the formulations that make up various brand products and contain certain ingredients that may pose other risks.

While controversy continues around Professor Seralini's branded glyphosate feeding trials on rats which showed liver, kidney, reproductive health and increased tumour growth, there are other research studies that also link glyphosate to a range of common health diseases and environmental issues.

Dr Don Huber, a former Monsanto chemist, claims glyphosate and other chemicals lead to destruction of soil qualities and reduced quantities of vital minerals in food crops.

Concerns in Argentina of cranial deformities in babies in heavily sprayed herbicide-tolerant GE soy cropping areas led to research by Professor Andres Carrasco published in Chemical Research in Toxicology, a medical research journal, showing glyphosate and glyphosate herbicides "interfere with key molecular mechanisms regulating early development of chicken embryos, leading to congenital malformations".

Research published in Reproductive Toxicology showed glyphosate herbicide traces in the blood of Canadian women who did not live near farms and so were likely exposed through food rather than spray drift. Other herbicide traces were also found in the foetuses of pregnant woman, according to the research, which calls in to question all herbicides used in food production.

Such results will often be criticised or debunked by scientific peers. But I think we also have to look for anything that might influence their thinking.

The use of glyphosate products is well established, from driveway weed spraying to paddocks and cropping ahead of new crops, and increasingly on food crops ahead of harvest, but the smart choice is to go away from its use.

With the amount of research indicating problems associated with the herbicide, I'd put money on it being withdrawn in general within 10 years. Before our trading partners begin banning it, in my view farmers and growers need to become familiar with the available internet literature and assess the risks to their business through continued use. We need to be looking at a phase-out of glyphosate and considering the use of different sets of management tools now. I want farmers across all sectors doing well without buying into potential market access or liability problems.

There are numerous positive examples around New Zealand of alternative farming practices to counter weeds, or for desiccation, the spraying of pasture and some food crops to even ripening or remove foliage ahead of harvest. Desiccation is contrary to consumers' perception of how their food is produced.

I think herbicide harvests do not fit with what New Zealanders or our export customers expect, and a clean green 100% Pure export brand needs a more progressive stance.

The Marlborough Express