The draft report was posted on a 'members only' page of the society's Web site (www.toxicology.org). Not surprisingly, it circulated more generally by E-mail and made its way onto the Internet.
According to society secretary Kendall Wallace of the University of Minnesota, Duluth, "any member can suggest to the council a topic to consider" for study. Once the council, composed of the society's elected officials, approves the suggestion, it asks appropriate sections to nominate experts to serve on a working group. In this case, the group consisted of six participants—they met for the first time a year ago—with Wallace acting as society liaison. The council Okayed the preliminary draft for posting to the membership.
Wallace concedes that biotechnology is a controversial topic, but that didn't keep the poison mavens from tackling it. "If we are a leading force in toxicology science, it was incumbent upon us to make a statement," he says. "To be silent on the issue would be a disservice to society in general."
The toxicology study comes on the heels of a report issued by the UK Royal Society in February calling for better safety assessment of genetically modified foods (www.royalsoc.ac.uk).1
Scientists and industry advocates who support GM crops insist the plants should be judged on the basis of their content—whether they are 'substantially equivalent' to cousins bred via traditional practices—rather than on the molecular tricks that birth them. The new report forcefully supports that stand. "The safety of current biotechnology-derived foods compared to their conventional counterparts can be assessed with reasonable certainty using established and accepted methods of analytical, nutritional, and toxicological research," the study concludes. Based on available tests, there's no reason to suspect that transgenic plants differ in any substantive way from traditional varieties.
By affirming the substantial equivalence standard, the report indirectly questions the better-safe-than-sorry 'precautionary principle,' long advocated by biotech critics as a strategy to ban the super crops. It also sides with a view dear to the hearts of agricultural technology champions: New crops should be judged on a case-by-case basis.
Skeptics argue that inserting foreign genes into plants could disrupt normal metabolic pathways or turn on cryptic processes leading to the accumulation of toxins. Biotech crops expressing non-native proteins—such as Bacillus thuringiensis (Bt) insecticidal toxins in corn—could foster allergic reactions in sensitized consumers. That concern prompted what's now known as Tacogate—in fall, 2000, the Food and Drug Administration recalled hundreds of corn-based products contaminated with a gene for Cry9C Bt toxin, which had been banned for human consumption.2 Circumstantial evidence indicated Cry9C could be allergenic.
The toxicologists see no current danger from allergies, citing tests conducted by the Centers for Disease Control and Prevention in collaboration with the FDA.3 The report takes an even wider perspective in concluding that "over 5,000 field trials with more than 70 transgenic plant species have been conducted since 1987 in the [United States] by the Department of Agriculture's Animal and Plant Health Inspection Service. In only one instance has an unexpected result been seen," and that involved surprising color patterns in petunia flowers.
Biotech advocates maintain that conventional breeding is just as risky if not more so because large numbers of unknown genes are transferred along with traits of interest. Yet, transgenic foods are unfairly held to higher safety standards than conventional crops, merely because of hypothetical risks posed by molecular biology. The report essentially supports this contention. "The extent of the genetic changes resulting from conventional breeding techniques, which is generally undefined, far exceeds that typically produced by transgenic methods," the toxicologists say. They even question whether the term 'genetically modified' is a useful distinction in light of wholesale gene juggling practiced 'the old fashioned way.'
The report didn't throw caution to the wind, though. Future biotech crops containing multiple or stacked traits could pose problems that would be difficult to detect with current tests. The authors of the study conclude that "there is no guarantee that all future genetic modifications will have apparently benign and predictable results." That's why they call for "a continuing evolution of toxicological methodologies and regulatory strategies to ensure that this level of safety is maintained."
The draft report is subject to change by Society of Toxicology members. Comments will be forwarded to the working group, which will then get any revision back to the council for final approval, probably in early May.
1. See also S. Mayor, "Better safety checks needed on GM foods," www.the-scientist.com/news/20020206/04.
2. B.A. Palevitz, "EPA reauthorizes Bt corn," The Scientist, 15:11, Oct. 29, 2001.
3. National Center for Environmental Health, "Investigation of human health effects associated with potential exposure to genetically modified corn," www.cdc.gov/nceh/ehhe/Cry9cReport.