http://www.reninet.com/catz/round.htm
Product: ROUNDUP
Active ingredient: GLYPHOSATE 41%
Type: HERBICIDE, (Systemic)
Other ingredients: 59% includes polyethoxethyleneamine
(POEA) and isopropylamine
(amount undisclosed); identity of remaining ingredients
withheld by manufacture as
trade secrets.
Mode of Action: Inhibits enzymatic activity necessary for
aromatic amino acid
biosynthesis, a process specific to plants. Other enzyme
systems in plants and animals not
specific to this biosynthetic pathway are affected by
glyphosate. (Heitanen et. al. 1983)
Of pesticides used during 1994, glyphosate was #7 for
overall total pounds of active
ingredient applied in California. Of the total glyphosate
used in California in 1994, 10%
was used in grape production, yet grapes were the number one
crop associated with
glyphosate- related illnesses from 1984 to1990 (Pease1995).
TOXICOLOGY
In California agriculture, Roundup's active ingredient,
glyphosate, ranked 3rd for
reported pesticide related skin and eye acute illnesses,
15th for reported systemic and
respiratory acute illnesses and 3th for reported pesticide
related acute illnesses of any
kind from 1984 to 1990 (Pease 1993). It ranked eighth in
acute illnesses per million
pounds applied.
Roundup inhibits enzymes involved in the detoxification
of chemicals in the body.
Test animals injected with glyphosate showed depressed
function of cytochrome P450
and two other enzymes which are vital to the body's
processing of toxicants (Heitanen
1983). At least two enzymatic steps are involved in the
processing of toxicants in the liver
of humans; the first involves cytochrome P450 enzymes and
the second involves
glutathione S tranferases (GSTs). People who do not possess
certain GSTs due to genetic
variation (estimated at approximately 50% of the Caucasian
population), may have a
greater risk of some types of cancer (Perera 1996).
U.S. EPA has recently reclassified glyphosate as a Group
E chemical, meaning that
evidence exists that the compound is not a human carcinogen.
Studies submitted to the
California Department of Pesticide Regulation have shown
possible adverse cancer
effects, with rare tumor formation in the kidneys and
adrenal cortex of test animals.
Other studies found an increase of testicular tumors,
thyroid cancer in females, and a
rare kidney tumor (U.S.EPA 1982;1983;1985;1991).
Metabolites and breakdown products of glyphosate include
the known carcinogen
formaldehyde (Lund 1986). Formaldehyde is listed as a
carcinogen by California's Office
of Environmental Health Hazard Assessment under Proposition
65. It also causes gene
mutations and is a reproductive toxicant (MBTOC 1995).
N- nitrosoglyphosate, a contaminant of glyphosate, is a
member of a chemical
family of which approximately 75% are known carcinogens
(Lijinsky 1974; Sittig 1980).
Glyphosate is a severe eye irritant. Symptoms of external
exposure to glyphosate
products include eye and skin irritation, which is sometimes
quite severe and can persist
for months (Temple and Smith 1992).
A study in humans documented a greater incidence of
impaired lung function,
throat irritation, coughing and breathlessness in workers
exposed to dust of flax treated
with Roundup, as compared to those exposed to untreated flax
dust. (Jamison 1986)
A low dose exposure study in experimental animals
demonstrated salivary gland
abnormalities related to changes in adrenalin levels when
the animals were exposed to
glyphosate. Changes were also observed in the kidney, liver,
and thymus of the animals
(U.S. Department of Health and Human Services).
An unknown percentage of Roundup's formulation is
composed of
Polyethoxethyleneamine (POEA), which is a surfactant added
to enhance the
performance of glyphosate. POEA is three times as acutely
toxic as glyphosate (Sawada
1988), is irritating to eyes and skin, and causes
gastrointestinal problems(Monsanto
1992). POEA is contaminated by 1,4 dioxane during the
manufacturing process (NCAP
1990). U.S.EPA regards 1,4 dioxane as a probable human
carcinogen. OEHHA recognizes
1,4 dioxane as a carcinogen under Proposition 65.
In animal tests, a mixture of glyphosate and POEA caused
cardiac arrest
(UNEP/WHO/ILO 1994). The amount of Roundup, which is
composed of glyphosate and
POEA, required to kill rats is about 1/3 of a lethal dose of
either compound separately
(Martinez 1990,1991), suggesting that synergism of the two
chemicals may enhance
toxicity.
Another portion of Roundup's formula is composed of
isopropylamine, a neutralizing
agent. It is extremely destructive to tissue of the mucous
membranes and upper
respiratory tract (Sigma Chemical 1994).
ENVIRONMENTAL FATE AND EFFECTS
Glyphosate is a candidate for evaluation as a toxic air
contaminant by the California
Department of Pesticide Regulation. Formaldehyde, one of
glyphosate's breakdown
products, is listed as a toxic air contaminant. (DPR 1994)
Between 14% and 78% of glyphosate applied as a ground
spray drifts off site
(Freedman 1990, 1991). It has been documented to affect
plants as far as 131 feet away,
and residues have been detected 1,312 feet downwind (Marrs
1993; Yates 1978).
Glyphosate is highly persistent in soil, taking from 24
to 249 days for one- half of it to
transform or biodegrade (Lappe 1996).
Glyphosate has been found in surface water as the result
of agricultural run-off (Frank
1990; Edwards 1980) and in ground water (U.S.EPA 1992).
Roundup is highly toxic to fish and aquatic organisms
(Product label). Juvenile fish
are particularly sensitive to the toxic effects of Roundup.
Physical and chemical factors
such as temperature, pH and solute concentration in aquatic
ecosystems influence the
acute toxicity of glyphosate to aquatic organisms (Caltrans
1991).
Glyphosate was shown in one study to inhibit the growth
of mycorrhizal fungi,
organisms which are essential to ecosystems and enhance
plant survival (Cummins
1991).
Acute toxicity to mammals, birds, and bees is low, but no
information is available
regarding long term effects to these organisms. No data is
available regarding the
toxicity of glyphosate to soil invertebrates, reptiles or
amphibians. (Caltrans 1991)
FRAUD AND PROFIT
Laboratories contracted by the manufacturer to conduct
toxicological analysis on
glyphosate have twice been documented as falsifying data for
these tests (U.S. Congress
1984; EPA 1994).
Public perception of Roundup has largely been shaped by
high profile advertising
campaigns of its manufacturer, Monsanto, which has a high
economic stake in its
continued use. According to The Wall Street Journal (1/2/96)
Roundup accounts for one
half of Monsanto's earnings. Monsanto's advertises that
Roundup can be used, "where
pets and kids play" and that it, "breaks down into natural
materials when its work is
done." But in 1996 the New York Attorney General fined
Monsanto $50,000 for these false
claims and extracted a promise from Monsanto to never again
advertise in the state
that Roundup is safe.
References
Californians for Alternatives to
Toxics
P.O. Box 1195, Arcata, CA 95518 USA (707)
822-8497(fax 7136) catz@reninet.com
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