Re-analysing the data, it's conceivable that they genuinely found a link, and that the papers' original authors were fudging the stats. But I don't know how to find out whether this is true.
It’s not a paper of original research but a meta analysis of various other scientist’s research which they selectively edited out the papers and science that didn’t support the agenda they had pre-determined. This was the description of the report that was originally given:
>> A Working Group of 17 experts from 11 countries met at the International Agency for Research on Cancer (IARC) on 3-10 March 2015 to review the available published scientific evidence and evaluate the carcinogenicity of five organophosphate insecticides and herbicides: diazinon, glyphosate, malathion, parathion, and tetrachlorvinphos.
Caprolactam used to be the the only chemical IARC had ever classified in their group 4 "probably not carcinogenic to humans" [1] but in 2019 they moved it to group 3 [2].
It wasn't supported by the conclusions they originally included. That doesn't mean the data didn't support it (although that might also be true – I don't know).
Many of the studies were likely funded by Monsanto, so it's predictable that they would be biased. So doing independent analysis would be wise. But then, it's also possible that some of the WHO staff or consultants were biased.
Someone would need to look at the original studies and work done for the WHO report. That'd be a lot of work. And it'd be hard to find anyone that both sides would trust.
“Portier, an American statistician who worked for the federal government for over thirty years, was the special advisor to the IARC panel that issued the report declaring glyphosate to be “probably carcinogenic.” The transcripts show that during the same week in March 2015 in which IARC published its glyphosate opinion, Portier signed a lucrative contract to act as a litigation consultant for two law firms that were preparing to sue Monsanto on behalf of glyphosate cancer victims. His contract contained a confidentiality clause barring Portier from disclosing his employment to other parties.”
It is easy to view these Glyphosate wars as tiny heroic Davids battling a vast malicious Goliath, and huge multinationals certainly can get up to all sorts of dubious stuff—but so can the “little guys”. And we have been here before: just look at Andrew Wakefield, found balls deep in lawyer money and rival patents, and still causing serious harm (e.g. 79 dead in Samoa) a decade after being busted for the mendacious money-grabbing little shit he really was.
As for the WHO, while it has done a great amount of very good work over the last 70 years, it is a human institution like any other and thus not immune to errors and corruption.
>> A Working Group of 17 experts from 11 countries met at the International Agency for Research on Cancer (IARC) on 3-10 March 2015 to review the available published scientific evidence and evaluate the carcinogenicity of five organophosphate insecticides and herbicides: diazinon, glyphosate, malathion, parathion, and tetrachlorvinphos.
https://www.iarc.fr/featured-news/media-centre-iarc-news-gly...
The article said they added their own statistical analysis that wasn’t supported by the data they originally included:
> In one instance, a fresh statistical analysis was inserted - effectively reversing the original finding of a study being reviewed by IARC.