The component's use accelerated particularly sharply in the 1990s when Monsanto started selling seeds that had been genetically modified to resist glyphosate herbicides (so called "Roundup ready" crops); these crops make up most of the corn and soya beans grown across North and South America. In 2013, Monsanto asked the US Environmental Protection Agency to agree to raise the level of the chemical considered "safe" - which was duly done, with everyone apparently satisfied that the product was still being used at levels safe for humans.
Concerns about glyphosate have been raised many times over the years, but in each case they have been quashed. In Sri Lanka and Nicaragua, glyphosate herbicides have been blamed (along with other factors) for chronic kidney disease in agricultural labourers, but attempts to ban or modify the use of the product have been met ferociously by its producer.
Monsanto is once more marshalling its legal troops over the latest report by the International Agency for Research on Cancer (IARC), an arm of the World Health Organisation, which asked 17 experts to assess five different, commonly-used pesticides from publicly-available studies conducted back as far as 2001. Three, including glyphosate, were deemed "probable" carcinogens.
The guts of it was that the chemical had been detected in the air during spraying, in water and in food. In workers that had been exposed to glyphosate in the US, Canada and Sweden, there was an increase in the incidence of non-Hodgkin lymphoma cases - and mice exposed to it were more likely to develop other, various cancers.
More importantly, perhaps, is that "glyphosate has been detected in the blood and urine of agricultural workers, indicating absorption".
And "glyphosate and glyphosate formulations induced DNA and chromosomal damage in mammals, and in human and animal cells in vitro".
Monsanto has, predictably, fought the findings, saying they don't gel with those of countries around the globe that have found glyphosate herbicides safe to use. The company accuses IARC of "cherry-picking" data and the agency's report of containing poor data.
IARC does take a pretty conservative view when synthesising studies, according to a report in the Sydney Morning Herald, which points out the agency demarked alcohol, tobacco and asbestos as "carcinogenic", night shifts and work as a hairdresser as "probably carcinogenic", and coffee "possibly carcinogenic".
That said, many things we now consider dangerous were once considered safe or "mostly" safe, and studies appeared to back those findings. Furthermore, it seems scary that we are pumping this product so heavily into our ecosystem - a chemical that was originally used as a descaling agent in pipes - without a huge dollop of over-caution.
But most remiss of all: where is the official comment on this major report? We almost stopped the country's entire trade in infant milk powder over a serious threat of contamination - and fair enough - but what about cautions to our friends in agriculture to consider reports that, at the very least, paint a worrying picture of something they are routinely exposed to?
The greatest risk to those using glyphosate herbicides is not to the urban gardeners, according to the latest report, but that hasn't stopped warnings being issued in some countries to gardeners to "hand weed to be on the safe side".
We can only hope that if there's a "safer side" to be on, New Zealanders would have heard about it by now.
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