Letter: GM food furore

Sir: GM plants tolerant to herbicides will, presumably, contain herbicide residues. The "precautionary principle" requires that we assume these residues may harm us when we eat them, unless and until they are proved safe.

The Salk vaccine has done a magnificent job over the past 40 years in saving many from polio: it is only now that it has been found that it may have caused cancers.

That was a very worthwhile benefit and arguably justifies its use despite this new-found side effect. The only benefit from herbicide-tolerant GM foods is to make some rich people richer.

Dr K N CHANDLER

Swansea