Hi Everyone,
One of the issues in this GM debate that is causing some misunderstanding is the language of toxicology.  Lloyd Spear wrote in part:

>Perhaps such a presentation, as well as a question and answer opportunity,
>might clear up the use of terms such as "practically non-toxic" and "the
>NOEL is greater than 20 ppm".

"Practically non-toxic" only means that the experiment done did not show any overt toxic effects and remember it was given as a one time ie "acute" test.  A researcher in toxicology who has only done "acute" tests will not rule out the possibility of other toxic effects if the material being tested is given over a longer time ie a "chronic" test and therefore will not usually say non-toxic.  NOEL = No Observed Effects Level  the dose at which no measurable toxic effects can be observed.  It of course takes several tests both acute and chronic to determine this level but if one does a single test and finds no observable effects the NOEL is greater than the dose given in the test.  Now it probably should have been said " acute NOEL is greater than 20 ppm" but elsewhere it noted that only a single short term test was done.

My own concern about the BT corn and other crops is a little different and has been touched on by others already.  By using the BT toxin in large acreage of crops we are selecting very rapidly for resistance to the toxin in the pest population.  By doing this we will select for and see pests that are resistant to BT which is one of the mainstays of the organic and alternative pest control methods and has been for many years.  The result will be that the organic folks and those who use low impact pest controls like IPM will loose one of the best and lowest environmental impact controls for caterpillars.

Interesting discussion with ramifications for all of us in agriculture.

blane


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Blane White
MN Dept of Agriculture
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