A startling new unpublished report from Britain concludes that it is inevitable that genetically engineered crops will contaminate organic food. The report by biotechnology and agriculture experts at the John Innes Centre found that pollen from engineered plants can spread far beyond the boundaries of fields.

The report recommends that organic farmers set a standard for acceptable levels of genetically engineered content, and that a system for checking for contamination be put into place. "Neither source of contamination, either pollen or seed, can be entirely eliminated, so acceptable levels have to be decided on," says the report, Organic Farming and Gene Transfer from Genetically Modified Crops.

Current organic standards in the US and around the world require zero levels of genetically engineered content in organic food.

The authors of the British report reached their conclusions after examining data from trials of engineered crops to see whether the proposed "buffer zones" between fields of GE and organic crops would protect them from contamination. The report found that pollen from genetically engineered crops can travel large distances on the wind, and is also carried by insects. With maize pollen, "in normal weather conditions, pollination could occur at sites remote from the source (e.g. 180 kilometres)," the report found.

In Britain, official genetically engineered crop trials operate with only a 200-yard buffer zone. The Soil Association, which regulates organic farming in Britain, says a six-mile barrier is the minimum needed to guarantee organic crops are not contaminated.

In the US, genetically engineered crops have already contaminated a shipment of organically grown corn for chips produced by the Wisconsin company, Terra Prima. The chips were found to be contaminated after they were shipped to Europe and tested there - costing the company several hundred thousand dollars.

In Canada, the National Farmers Union (NFU) is calling on the Canadian government to make agricultural biotechnology companies financially responsible for "genetic pollution" of organic and traditional crops.