Re: Roundup Safety issues

Frank Teuton (fteuton@total.net)
Mon, 24 Aug 1998 10:20:12 -0400

> Date: Tue, 18 Aug 1998 08:55:07 -0500
> From: "Wilson, Dale" <WILSONDO@phibred.com>
> Subject: RE: Roundup Safety issues
>
> Frank,
>
> > Dr. Trotter posted a query a while back on no-till which begged a
> > question I have been laboring over. For those who use Roundup
> > and those
> > who refuse to use it, how do you interpret the science of Roundup
> > safety, both in terms of human health and also environmental
> > consequences?
>
> When I was an undergraduate in the mid-seventies, glyphosate was sort of
> a miracle herbicide. We were taught that it is rapidly immobilized in
> the environment, and then degraded. With an LD50 of about 5g/kg it was
> a lot safer than other herbicides in terms of acute toxicity. I have
> used Roundup quite often, and it seems to be bound and inactivated
> immediately by the soil. It sure is bad though when the spray drifts
> onto corn or cucurbits! Also, some broadleaf weeds appear somewhat
> resistant. Additional surfactant appears to improve it a great deal.
>
> When the matter came up on Sanet a while back, I pulled about 100
> references out of Agricola on the toxicology and persistence of
> glyphosate, since I had never personally looked at the primary
> literature on this subject.
>
> Perusal of the abstracts tended to support safety. Apparently you have
> to drink about 300 ml of Roundup concentrate to kill to yourself.
> Glyphosate from small oral doses is about 99% eliminated via the urine
> in about a week. It is not absorbed through the skin very easily. Even
> applied directly to water for control of aquatic weeds, glyphosate
> doesn't have much effect on aquatic animals, or submerged plants.
> Surfactants can increase toxicity to aquatic animals. It is bound
> rapidly by colloids in soil and water and is broken down in a few weeks
> by bacteria. Frequent applications can reduce rate of earthworm growth.
>
> If people are interested, they should read these papers, not just the
> abstracts, and see how credible the work was. If anyone is interested,
> I'll send them the search results.
>
> > I have read Caroline Cox's 48 page compilation of
> > references indicating problems with Roundup in
> > the Journal of Pesticide Reform.
>
> Have you got that in electronic format? I'd like to look at it.

http://host.envirolink.org/hecweb/archive/glyphos1.htm

http://host.envirolink.org/hecweb/archive/glyphos2.htm
>
> > Is all this, to use Dr. Trotter's term, 'junk science'? And if it
> > is, how do we avoid the other side of the coin, 'whore science'?
>
> Anything that is not peer-reviewed is immediately suspect. If it is
> peer-reviewed, what is the nature of the community? I tend to discount
> sources that are intentionally polemic. I would take a source like "J.
> Pesticide Reform" with a grain of salt, just like I would Monsanto trade
> literature. Journals published by long-standing scientific societies
> with a tradition of scholarship are probably reliable. Ultimately one
> has to dig in the literature, read the papers, and judge for themselves.

Thanks for your response, Dale. I posted the URLs above.
>
> Dale Wilson
>

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