Glyphosate residue limits in soya relaxed to accommodate GM crops

The European Union (EU) has substantially increased the maximum residue limit allowed for glyphosate in imported genetically modified (GM) soya. Has pressure from the makers of GM herbicide tolerant crops over-ridden consumer concerns? Sue Dibb reports.

Farmers in the US, who have been using the GM technology since the late 1980s, are already concerned about weeds in fields of soya that glyphosate cannot control, or which are not controlled at the rates of herbicide application for which they are willing to pay.
    These levels of herbicide use are likely to result in the increased  incidence of residues in the soya crop. To accommodate this, Monsanto, the major manufacturer of glyphosate, has successfully applied to the EU to raise the maximum residue limit for glyphosate 200 times from 0.1 mg/kg to 20 mg/kg. In conventional systems, residues would be less likely to occur in soya because the product cannot be used whilst the crop is growing—it would have killed the crop along with all the weeds. The GM herbicide tolerant soya, however, is more likely to contain residues because the crop has been genetically designed to withstand the herbicidal effects of glyphosate. Similar standards have been set at Codex, the WHO/FAO food standards agency, and applied for in Australia and New Zealand.
    Many public interest groups  around the world are concerned that the decision to raise permitted residue levels, is a move in the wrong direction. It is, after all, contrary to the current trend with other residue limits, such as drinking water and baby food, where the EU has some of the strictest standards in the world.
    In a BBC interview in June a spokesman for the supermarket chain Sainsbury’s confirmed that their tests were now finding residues of glyphosate in imported US soya, and the company has raised the issue with the Ministry of Agriculture, Fisheries and Food (MAFF). MAFF responded by saying that “residues pose no identifiable risk to consumers.” But current levels of contamination are not clear, as the most recent MAFF reports on pesticide residues contain no data  on residues of glyphosate in soya(1), and supermarkets are unwilling to make their results public.
    Glyphosate is now the world’s most commonly used pesticide—and its use is increasing rapidly with GM glyphosate-tolerant crops. It is currently applied to at least 70 million hectares world-wide, and between 1997 and 1998 sales have increased by a massive 25%.
    The UK approval of glyphosate is based on data submitted in the 1970s, and MAFF has not reviewed the safety and environmental effects of this chemical to today’s standards, as they have done with a number of other older pesticides.
    New research has raised concerns over health effects which may be caused by glyphosate. It says non-Hodgkin’s lymphoma, one of the most rapidly increasing cancers in the Western world, is linked to several commonly used herbicides. The chemicals suppress the patient’s immune system, allowing viruses to trigger cancers. Although the sample size was small, researchers found that Swedish sufferers of the disease were two to three times more likely to have had contact with glyphosate(2).

1. Annual Report of the Working Party on Pesticides Residues, (latest edition) September 1999.
2. Lenart Hardell, A case control study of non-Hodgkin’s lymphoma and exposure to pesticides, Cancer, 1999, Vol. 85:6. 

Sue Dibb is Co-Director of the Food Commission, which campaigns for safer, healthier food and  publishes the Food Magazine, 94 White Lion Street, London N1 9PF,  Fax. +44 (0)171 837 1141.

[This article first appeared in Pesticides News No.45, September 2000, page 5]