The Environmental Working Group (EWG) has come out with an article "Breakfast With a Dose of Roundup?" based on a study of the presence of toxic glyphosphates (pesticides) present in many conventional wheat products. The recent EWG study was triggered by the award of $289 million dollars to a California man dying from cancer caused by exposure to Monsanto product called "Round-up". The study found that 31 out of 45: conventional producers of wheat products had higher than safe levels of pesticide. This is problematic because these unsafe levels of pesticides are still legal according to regulatory agencies.
A 2009 study looked at 13 people with pesticide poisoning from consumption of wheat bagels. Found that acute exposure can cause: nausea, dizziness, vomiting in individuals. But, long term effects can be fatal. (Read more: Kavalci C. "Organophosphate poisoning due to a wheat bagel." Intern Med. 2009;48(2):85-8. Epub 2009 Jan 15).
The solution is to eat wheat products organic sources. These are have very low to no detection of pesticides and therefore provide a much safer alternative.