Kathy Solomon's July 4th letter regarding soy-based foods may well contain factual elements. However, she states "... the seeds ... have been genetically-modified to incorporate glyphosate." That is not correct.
Glyphosate is a weed-killer. Roundup Ready seeds, which is what she refers to, have been genetically (not chemically) modified to be resistant to glyphosate so that the herbicide can be used around the crops and not kill them.
The EPA considered a "worst case" dietary risk model of an individual eating a lifetime of food derived entirely from glyphosate-sprayed fields with residues at their maximum levels. This model indicated that no adverse health effects would be expected under such conditions.
See U.S. EPA ReRegistration Decision Fact Sheet for Glyphosate (EPA-738-F-93-011) 1993 for more than you ever wanted to know. (It is available online at http://www.epa.gov/oppsrrd1/REDs/factsheets/0178fact.pdf )
I am not, by the way, an employee of nor a shill for (nor even a fan of) Monsanto. I am moved to act when misinformation is published as established fact (with no backup references).