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nafex - Re: [NAFEX] Safest Systemic Killer for Stump?

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  • From: Hilborn.E@epamail.epa.gov
  • To: Unschooler@lrec.org, North American Fruit Explorers <nafex@lists.ibiblio.org>
  • Subject: Re: [NAFEX] Safest Systemic Killer for Stump?
  • Date: Wed, 29 Sep 2010 11:52:24 -0400

Roundup has never been marketed as being nontoxic. However, this Mother
Earth article is misleading. Here is the link to the abstract from the
original paper: http://www.ncbi.nlm.nih.gov/pubmed/19539684

The scientists describe dosing liver cells in culture, there was no
direct effect observed on reproductive cells as stated in the article.
Remember that dosing cells in culture may help to identify broad
categories of risk, but is not the same thing as exposing a whole
organism.

If you have to use an herbicide, glyphosate, (the active ingredient
itself) is still considered one of the least toxic among herbicides.
See:
http://text.lsuagcenter.com/NR/rdonlyres/2B8BEF0F-BD60-4651-B240-0F36884D997C/56790/28RelativeToxicity09.pdf

(BTW- LD50 is lethal dose 50, it means that at that dose, 50% of exposed
animals die. It is a crude measure of comparative acute toxicity.)

As you suggest below, inert ingredient formulations matter in the
toxicity of various glyphosate formulations and it is hard to get
specific manufacturer information about the composition and absolute
toxicity of these.

One approach I have personally taken is to buy formulations meant for
treating aquatic vegetation, as these inert ingredients have been
selected specifically as having lower toxicity for aquatic animals. I do
use them near wetlands, so I figure it benefits me and the environment.
The aquatic formulation seems equally effective as
commercially-available premixed "Roundup" on my target plants which are
mostly terrestrial, not aquatic. However, I have noticed that it can
take up to 5-7 days to see the killing effect rather than the 24 hours
that some premixed "Roundup" formulations promise.

I think that it is prudent to always wear protective gear, minimize
exposure and use caution when working with potentially toxic chemicals,
even commonly used ones.

These are my personal statements and in no way represent those of the
Agency.

Betsy Hilborn
7a NC



From: Leslie Moyer <unschooler@lrec.org>
To: North American Fruit Explorers <nafex@lists.ibiblio.org>
Date: 09/28/2010 11:24 PM
Subject: Re: [NAFEX] Safest Systemic Killer for Stump?
Sent by: nafex-bounces@lists.ibiblio.org



On 9/28/10 6:42 PM, Matt Demmon wrote:
> Most people consider glyphosate (active ingredient in Roundup) to be
> one of the 'least toxic' of herbicides. It's supposedly not very
> persistent, and not very harmful to humans.
A true statement about "most people", I imagine, and I used to feel the
same way. However, there has been plenty of information to the contrary.

Here's an excerpt from a post I sent to another list earlier this spring

that references the medical journal, Toxicology:

This is such an important topic in light of the huge increase in
"Roundup Ready" seed use in the last few years.

http://www.motherearthnews.com/Sustainable-Farming/Roundup-Weed-Killer-Toxicity.aspx?utm_content=05.26.10
+SLCS&utm_campaign=SLCS&utm_source=iPost&utm_medium=email


To protect our health, the U.S. Environmental Protection Agency (EPA)
sets maximum legal residue levels for every pesticide, for dozens of
crops. But a new study in the respected journal Toxicology has shown
that, at low levels that are currently legal on our food, Roundup could
cause DNA damage, endocrine disruption and cell death. The study,
conducted by French researchers, shows glyphosate-based herbicides are
toxic to human reproductive cells.

<<snip>>

"... If a pregnant woman were to be exposed early in gestation, it looks

like these herbicides could have an effect during the sexual
differentiation stage. They really lock in on testosterone.”

<<snip>>

Despite being termed “inert,” these added (and usually secret)
ingredients are anything but benign, as the manufacturers have claimed
for decades. The new French research found the surfactants not only
amplify the effects of glyphosate, but glyphosate also amplifies the
effects of the surfactants. Basically, one plus one equals something
larger than two.

<<snip>>

More in the article at the link above and you can find more about
glyphosate's toxicity--to humans and other biological creatures--if you
begin to look around.

-Leslie






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