WASHINGTON -- Animal experiments at Duke University Medical
Center show that harmless doses of three chemicals used to
protect Gulf War soldiers from insect-borne diseases and nerve-
gas poisoning are highly toxic when used in combination,
researchers reported Wednesday. They said the findings may
explain the wide array of symptoms reported by an estimated
30,000 Gulf In studies using chickens, the researchers
specifically found that two pesticides, DEET and permethrin, and
the anti-nerve gas agent pyridostigmine bromide (PB) were
harmless when used alone, even at three times the doses soldiers
likely received. But when used in combination, the chemicals
caused neurological deficits in the test animals similar to
those reported by some Gulf War veterans, according to Duke
pharmacologist Mohamed Abou-Donia and Tom Kurt, a toxicologist
at The University of Texas Southwestern Medical Center in
Dallas. Chickens were selected over rodents as test animals
because their susceptibility to neurotoxic chemicals more clo