Thanks for the references John...appreciate your work. one aspect of your note got me to thinking
>>the irony is that Bt corn is not (as far as I know) permitted for use as a human food. It is only used to feed cattle, so as the Bt corn strains increase in strength, then it is going to be unlikely or never that Bt corn will be ingested by humans
First, I think about issues of environmental justice: while such crops may not be *sold* for human food, it seems pretty unlikely that they will never be used as human food. People, often poor & disempowered people, live & work around fields, storage facilities, in transportation & distribution of such foods. We have no real control over who eats what. The protections we do have, as a species, are the traditional understandings of food stuffs. When we genetically change food it may well be that up-to-date educated folks will ponder the complexity of the issue---but hungry folk will eat what is there & assume it is food they are used to. In the past crops designated as "animal food" were not actually dangerous--simply undesirable.
An anecdote that remains vivid for me is one I read some time ago (sorry, no reference--I'll see what I can dig up later) in which an outdated hospital x-ray machine was inadvertently scrapped with its radioactive core intact. Business deals led one to the next, as they are prone to, and somehow the old x-ray machine wound up in a junkyard in a remote region of Mexico. The people there managed to force open the core and all around men, women & children marveled at the seemingly magical soft phosphorescent powder contained within. People dipped their fingers in the powder, painted designs on their faces & even tasted the beautiful, glowing substance.
How can we possibly guard against such events? People are so incredibly varied in socialization, education & belief system. To fundamentally change the nature of food seems, in a way, almost arrogant.
ennyhoo. my $ 0.02
anne
----- Original Message -----
From: John Foster <[log in to unmask]>
Date: Thursday, July 31, 2003 2:31 am
Subject: Bt Corn
> Hi Anne,
>
> after re-installing the OS on my computer I removed all the
> references. However hard work and time is required to get to the
> bottom of the topic.
>
>
> The topic of GM crops is complex and the environmental science is
> evolving. Here is one reference which in essence indicates that
> with some strains of Bt corn the risk to insects is significant,
> and not only for Monarch butterflies.
>
> Some insects are already becoming resistant to Bt corn, and this
> article refers to weak GM strains which the corn borer larvae can
> feed on and survive. So just as long as a few insects (there are
> over 500 species of plants and animals of economic importance now
> that are resistant to chemical pesticides) survive the Bt toxin,
> selectively these will be 'selected' because they survive and
> breed.
>
> Cockroches are just about as immune to chemical insecticides as it
> gets. In Central America it is now only possible to grow cotton if
> it is sprayed every other day, and I have heard of reports where
> cotton crops are sprayed over a 12 times in one season.
>
> Therefore resistance is a problem with Bt corn, and the irony is
> that Bt corn is not (as far as I know) permitted for use as a
> human food. It is only used to feed cattle, so as the Bt corn
> strains increase in strength, then it is going to be unlikely or
> never that Bt corn will be ingested by humans. Not only that but
> Bt corn cross pollinates with non-Bt corn.
>
> Eventually many of the susecptible 'migratory' or secondary
> insects in and adjacent to the more toxic strains of Bt corn will
> be seriously impacted. The following reference indicates that
> there are various existing problems and some 'mounting' problems.
> The early 'less toxic strains' have been ineffective in
> controlling the corn root borer. In order to be effective over the
> long term all corn borers in a field would have to be killed.
>
>
> "The Cornell study used a strain of corn from Novartis that
> contained up to 40 times more Bt toxin in its pollen than
> Monsanto's brand does."
>
> http://www.biotech-info.net/under_milkweed.html
>
>
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