Re: Re-registration of Bt crops should be delayed at this time

Dear Administrator Whitman:

On July 27, 2001, the EPA concluded that there was no reasonable scientific basis to conclude that any level of StarLink corn is safe for human consumption. Today, we submit new evidence demonstrating that the EPA has no reasonable scientific basis to allow, at this time, the human consumption of any variety of corn or potatoes genetically engineered with bacterial toxins derived from Bacillus thuringiensis (Bt) that the EPA is currently considering for re-registration. Due to the inhalation exposure to cotton dust by field workers and people who process Bt cotton, this crop should also not be approved for commercial planting at this time. The evidence in question derives from two sources: studies conducted after the original registration of Bt crops in 1996, and a re-examination of deficient studies submitted by registrants prior to the original registrations. In addition, the EPA has not collected or evaluated information the Agency itself deems as “required” for its human health assessment.

The EPA is supposed to base its reassessment on “the most current health and ecological data,” incorporating “all available scientific information on Bt products,” in particular the recommendations of its Scientific Advisory Panels and the National Academy of Sciences report on pest-protected plants.[i] As detailed in our submission to the EPA, the Agency has failed to do this.

Our comments focus on the three primary characteristics of known allergens by which the EPA decides whether Bt toxins have the potential to cause allergies. The toxins at issue either have these characteristics, or have not been adequately assessed for them. Of greatest concern are data showing that the bacterial toxin engineered into Monsanto’s Yieldgard corn and Syngenta’s Bt11 corn is resistant to digestion and heat, similar to the toxin engineered into StarLink corn. Corn containing the Cry1F protein registered to Mycogen/Pioneer may also exhibit digestive and heat stability (see attached table).

StarLink was not approved for human consumption because it had “characteristics of known allergens,” according to the EPA. Consequently, individuals and their physicians did not know to examine this particular type of corn to seek the cause of unexplained corn allergies that they suffered, sometimes severely enough to require emergency room admission. Only after hearing news of this potential allergen through the media did individuals know to consider it as a possible cause of their allergic response. Indeed, this summer, at least one individual was diagnosed by his allergist as “most likely” allergic to this corn, and the EPA’s scientific advisors recommended that he and others undergo further testing.

As long as products made with genetically engineered corn are not labeled, consumers will be exposed to potential hazards. Due to this situation, it is incumbent upon you to take all available measures to determine if other engineered varieties are allergenic or toxic to people before making any decision to re-register these crops for cultivation. The alternative is for the EPA to advise the Food and Drug Administration that the potential human health impacts [O1] of these crops remain uncharacterized and, therefore, that foods containing genetically engineered corn should be labeled “may cause allergic reactions or other adverse effects.”

According to a study by Aventis CropScience: “The Cry1Ab protein was digested at a similar, if slightly faster, rate than the E. coli-derived Cry9C protein in simulated gastric fluid.”[ii] This finding of digestive stability was confirmed by Dr. Hubert Noteborn, who also found that, unlike other Cry proteins, the Cry1Ab protein exhibits “relatively significant thermostability … comparable to that of the Lys mutant of Cry9C protein” found in StarLink.[iii]

The EPA has failed to collect data on the third criterion, amino acid homology to known allergens and toxins, for two of the three varieties of Bt corn. The data available for Bt cotton and potatoes is likewise lacking or deficient.

The issues raised, above, in summary form are discussed in more detail along with other concerns in an annotated document we have submitted to the Bt re-registration docket, OOP-00678B. The full submission will be posted at www.foe.org/safefood.

We urge you to delay the registration of Bt crops currently under consideration unless complete and adequate studies on potential health impacts, as noted above, are submitted by the biotechnology industry or are conducted. The health of the American people, confidence in the food supply and the vitality of our farm economy depend on it.

Sincerely,

Larry Bohlen

Director, Health and Environment Programs