(Monday, Feb. 23, 2004 -- CropChoice news) -- Reuters: KUALA LUMPUR - Filipino farm workers living by a field of gene-modified maize showed signs of exposure to the plant's anti-pest toxin three months after the pollen season, Norwegian scientist Terje Traavik said on Monday.
Blood samples from 39 people in a farm community on the southern Philippine island of Mindanao carried increased levels of three different target antibodies, evidence of an immune reaction to the Bt toxin built in to combat pests, he added.
"We are absolutely sure it's a reaction to being exposed to the Bt maize," Traavik told Reuters on Monday at the start of international talks on trade in genetically modified (GM) crops.
The timing of the immune response, which was not equivalent to conventional hay fever, coincided with maize flowering in June.
If more tests were to confirm his findings, they would fuel anti-GM campaigner arguments that extra caution is needed before wide-scale cultivation of modified crops such as maize, canola and cotton goes any further.
Biotech companies say their GM products are as safe as "substantially equivalent" natural varieties and need no additional safety tests or measures.
Critics say not enough tests have been done to be sure.
U.S. consumers have been eating GM foods such as Bt maize for several years and the country easily leads the world in terms of area under GM cultivation.
Traavik said the maize variety involved, sold as Dekalb 818 YG, came from U.S. crop company Monsanto .
The professor of gene ecology at Norway's University of Tromso is a critic of mainstream biotech research who says too few scientists are free from industry connections.
No one from Monsanto, whose representatives were present at the talks, was immediately available for comment.
Willy De Greef, a biotech law consultant formerly employed by Swiss agrochemicals company Syngenta, expressed surprise at Traavik's findings, saying research showed Bt maize pollen did not carry the toxin so no reaction should occur.
"One would want a scientific panel to look at Traavik's results," he said on the margins of the Malaysia meeting.