Good ol' Round up aye (it can be found in many-a garden shed) active ingredent glyphosate .
here's a little ditty from the Soil and Health Association on NZ

"a link between glyphosate and non-Hodgkin lymphoma,(Cancer) a possibility that can no longer be ignored. That being the case, it can be concluded that a precautionary approach should be taken to any further use of glyphosate in New Zealand until a definite link can be established or refuted with certainty." -- italics added by me.
"Non hodgkins lymphoma has risen 73 percent in the US since 1973 (about the time RoundUp was introduced). (wow that's a coincidence isn't it?)

So you might say yay to GE onions or (Roundup-ready herbicide resistant onions) but lets take a look at what the US Department of Agriculture itself says --overall herbicide usage has increased since the introduction of herbicide-resistant crops. In particular, it says that up to 30 percent more herbicide are being used on herbicide resistant Soya beans (what is to say this won't happen to clean green NZ onions. (yummy) (by the way Organic (not using any toxic or harmful chemicals) Onions are being grown in the Hawkes Bay with great success)it looks like some people have the right idea :)

and a further note to add
"to accommodate RoundUp ready crops, regulatory authority's world wide agreed to a 200-fold increase in acceptable residue levels of herbicide in our food"

information from
-Soil and Health Association NZ
-article by Dr Robert Anderson from
Physicians and Scientists for Responsible Genetics -