For example, the facts quoted in the letter, as sourced from the Rodale Institute in the US, do not indicate the level of contamination in the various products - whether glyphosate was present as a mere trace, or whether it was within the acceptable limits as defined by legislation, or whether present at levels beyond the prescribed limits.

And one might ask what are the risks of contamination through means of exposure like skin absorption or inhalation or accidental ingestion. But not everybody agrees on these facts.

An article in the Daily Telegraph on June 8 portrays a different view on this issue, quote: "A Sydney environmental expert has fired a blistering attack against the 'hysteria' and 'misinformation' that popular weedkiller Roundup causes cancer, saying scientific evidence shows it's "our safest herbicide".

University of Sydney Emeritus Professor Ivan Kennedy, who has conducted risk assessments of pesticides for nearly 50 years, claims the recent landmark court verdicts in the United States against Bayer, the owner of Roundup manufacturer Monsanto, were based on emotion rather that scientific data.

One couple was awarded more than $2 million in damages after suing on the grounds that long-term exposure to glyphosate, the herbicide used in Roundup, had caused their cancer.

"This is very disappointing because, from my point of view, glyphosate is the safest herbicide that we have - and it's inherently non toxic," Prof Kennedy said.

"The court decisions, I believe, were based on emotion and there's all this hysteria and misinformation out there now."

His comments came as the first lawsuit was filed in Australia over Roundup's cancer link. Whom or what to believe? And how safe is safe?