PRESS RELEASE from PHYSICIANS AND SCIENTISTS FOR RESPONSIBLE GENETICS
23 October 2001
Transgenic Bt crops
Physicians and Scientists for Responsible Genetics note that the US Environmental Protection Agency has approved
genetically engineered Bt crops for a further seven years.
The EPA decision has been made despite its own scientific advisory panel - appointed to investigate and advise following
the StarLink corn controversy, and including leading allergists and independent scientists - called for more tests to
determine the potential allergenicity of Bt crops. This testing has not been carried out and, as the Aventis Bt corn
variety, StarLink, proved in 2000, allergenicity can result from ingesting a Bt transgene.
Bt sprays are an important management tool for sustainable farming methods. Bt engineered plants produce an insecticidal
or Bt toxin, one of a family of related molecules produced by Bacillus thuringiensis, a soil bacterium. The engineered
plant produces the toxin in most, if not all, of its parts, through all or most of a growing season. Toxins in Bt sprays
break down rapidly in the environment as opposed to the Bt in genetically engineered crops which breaks down very
slowly.
The EPA has not required biotechnology companies to conduct toxicity and allergenicity tests on the engineered proteins
produced in Bt crops, but accepts tests on surrogate proteins from bacteria. These can differ substantially from their
plant-produced counterparts.
Studies on potential environmental impacts of Bt corn are also inadequate. The Agency ignored the concerns of
researchers at Cornell and Iowa State Universities and the University of Minnesota whose recent studies suggest exposure
to Bt corn may have long-term, harmful effects on monarch butterflies. Biologists at all three schools involved in this
related research urged the EPA to delay its decision until more data were available.
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23 October 2001