Tuesday, May 02, 2006

Pesticides in cotton

http://www.sciencedaily.com/releases/2006/05/060501232015.htm

Bt (Biotech) cotton has been genetically engineered to contain Bt toxin, a naturally occuring insecticide. The good news is that farmers need fewer chemical insecticides, and insect diversity is not affected, when compared with conventional cotton. I noticed that although evaluations included uncultivated fields beside the cotton fields, this article did not mention how the uncultivated fields compared with the cotton fields in terms of biodiversity.
A factor of concern is the effect of the Bt or other insecticides on humans. In the past, cotton has not been subjected to the same restraints on the use of pesticides as food crops, despite the fact that cottonseed oil is widely used in processed foods. Many pesticides are fat-soluble. Since the current administration has repeatedly decreased standards for public health in favor of business profits, I doubt that this has changed for the better.

Another aspect not mentioned in this article is that insects have been evolving resistance to pesticides. Bt is unlikely to be an exception. Breeding it into cotton seems likely to hasten the development of resistance.

Also ignored is the likelyhood that the Bt cotton will interbreed with other wild and domesticated crops. Since it confers protection to some insects, I would expect the spread of the Bt genes to spread rapidly in plants, at least until insets gain resistance. This should result in resistance developing even more quickly.

If the Bt genes do spread to other plants, what will be the effects on human and animal health?

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