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http://www.ecwa.asn.au/info/glyphosb.html



Aquatic Effects
Seston is particulate matter of organic origin suspended in water,
usually detritus from surrounding bush and forest. It adsorbs
glyphosate much more readily than soil particles. However, this
adsorption can complex the chemical so that it can move into the
aquatic environment by erosion. This changes the effect of the
compound on aquatic organisms and it can alter the rate of chemical
and biological degradation.

Several studies have been done on aquatic organisms. However, low
concentrations of chemicals in the aqueous environment often can be
excreted by most aquatic organisms without adverse effect to either
themselves or the community in which they live. For these reasons, in
these studies, it becomes difficult to interpret the data. In
general, several studies reported that the increased toxicity of
Roundup is due to the surfactant (MON 0818) present in the
formulation. Evidence of the combined effect of glyphosate and the
surfactant showed an increasing effect to sockeye salmon, rainbow
trout and coho salmon. The investigators reported a 4.8 fold increase
in LC50 (for Roundup) as pH decreased from 7.5 to 6.5. The surfactant
was tested separately from glyphosate and found to be much more toxic
than glyphosate itself and even more toxic when combined.

Fish, amphibians and aquatic invertebrates are more sensitive to
glyphosate due to differences in toxicity between the salts and the
surfactants used in glyphosate-containing products. The toxicity is
increased with higher water temperatures, higher concentration and pH.
This toxicity can have a devastating effect on endangered species. In
Australia, guidelines state that most glyphosate-containing products
should not be used in or near water because of their toxic effects on
all aquatic species.

Studies conducted by the Department of Environmental Protection in
South West Australia in 1995 showed that tadpoles (which respire with
gills) were more sensitive to the full formulation than adult frogs.
The tadpoles were also considerably more sensitive to the formulation
of Roundup 360 than to technical grade glyphosate. Some surfactants
affect aquatic organisms by damaging the gill membrane. Frogs and
other aquatic organisms are exposed to herbicides through runoff or
overspray from treated areas adjacent to wetlands. LC50 values for
adult frogs in shallow water indicate there may be little difference
between lethal and non-lethal concentrations.

Fish - Both glyphosate and glyphosate-containing products are acutely
toxic to fish. However, glyphosate alone is less toxic than the
glyphosate product such as Roundup. Other glyphosate-containing
products have intermediate toxicity. The surfactant in Roundup causes
toxicity to fish and it is about 30 times more toxic to fish than
glyphosate itself. Acute toxicities of glyphosate alone varies. The
median lethal concentration (LD50) ranges from 10ppm to over 1000ppm
have been reported depending on the types of fish and test conditions.
Acute toxicities of glyphosate-containing products such as Roundup to
fish range from an LC50 of 52ppm. However, there are factors that are
important in determining the toxicity of glyphosate or
glyphosate-containing products to fish. They include;

Different species of fish have different susceptibilities. For
example, pink or chum salmon are less tolerant of glyphosate than coho
and chinook salmon.

Water quality.
Glyphosate is 20 times more toxic to rainbow trout in soft water than
is glyphosate in hard water.


Age.
Juveniles are often more susceptible than adults. For example,
Roundup is 4 times more toxic to rainbow trout fry and fingerlings
than it is to larger fish.


Nutrition/diet.
Hungry fishes are more susceptible to glyphosate than fed fish.
Glyphosate toxicity increases with increasing water temperature, pH
and concentration. For example, the toxicity of both rainbow trout
and bluegills increased with increasing temperature. Roundup was
twice as toxic to rainbow trout at 17?C than at 7?C. Roundup was more
toxic to both rainbow trout and bluegills at higher pH and even more
so if pH exceeds 7.5.
Human Effects
As with all mammals and aquatic organisms, glyphosate obviously
affects humans. Humans do not normally suffer acute toxicity from
glyphosate, however acute toxicity was first widely publicised by
physicians in Japan who studied 56 cases of Roundup poisoning. Many
of the cases were suicides. Symptoms showed in humans were
gastrointestinal pain, vomiting, excess fluid in the lungs, pneumonia,
clouding of consciousness and destruction of red blood cells. The
mean calculated in these cases was more than 200 millilitres (about ?
of a cup). It was believed that the surfactant in the product Roundup
caused the toxicity. There were also similar symptoms found such as
lung congestion or dysfunction, erosion of the gastrointestinal tract,
abnormal electrocardiograms, massive gastrointestinal fluid loss, low
blood pressure and kidney damage or failure. However, these are
caused by larger amounts of Roundup.

Smaller amounts of Roundup or glyphosate-containing products also
cause less lethal effects. Most incidents reported in humans have
involved skin or eye irritation. These are general cases and are
mainly confined to farmers or agricultural workers and especially
manufacturers’ workers. Nausea and dizziness have also been reported
after exposure. Swallowing the Roundup formulation caused mouth and
throat irritation, vomiting, low blood pressure, pain in the abdomen,
and reduced urine output. The amount swallowed was about 100
millilitres (about ? a cup).

The most important ways that people come in contact with glyphosate
are through work place exposure, eating of contaminated food, exposure
caused by off-target movement following application (drift), contact
with contaminated soil and drinking or bathing in contaminated water.

Conclusion
Glyphosate-containing products can be effective tools in weed control
programs. However, they are acutely toxic to terrestrial and aquatic
organisms as well as to humans. Laboratory studies have identified
effects of glyphosate-containing products in all standard categories
of toxicological testing. When glyphosate is added to the
environment, a chain of contamination is effected in all parts of the
environment including soil-water effects, ecological effects and human
health effects. Results of environmental fate studies clearly
indicate that if glyphosate is bound to soil particles it can have
serious effects on the environment because microbial activity is
unable to biodegrade it. Since glyphosate is being marketed as a safe
environmentally friendly product, there is a danger to non-target
plants as well as endangered plants and animal species. Habitat
damage and destruction will increase and food crops will be put at
risk. Glyphosate can be seriously detrimental to all living
organisms. Most importantly, all herbicide users should be aware of
the environmental effects involved.

Bibliography/Reference
Agriculture Canada. Food Production and Inspection Branch, Pesticides
Directorate. 1991. Discussion document: Pre-harvest use of
glyphosate. Ottawa, Ontario, Canada (November 27).
Bidwell, J.R. and Gorrie, J.R. (June 1995), Acute Toxicity of
Herbicide to selected frog species: final report. Technical Series:
79, Western Australian Department of Environmental Protection, Perth.
Brust, G.E. 1990. Direct and indirect effects of four herbicides on
the activity of carabid beetles (Coleoptera:Carabidae). Pestic. Sci.
30:309-320.
Buhl K.J. and Faerber, N.L. 1989. Acute toxicities of selected
herbicides and surfactants to larvae of the midge Chironomus riparius.
Arch. Environ. Contam. Toxicol. 18:530-536.
Cornell University, “Glyphosate”, 2001,
http://pmep.cce.cornell.edu/profiles...osate-ext.html
(Accessed 4 July 2001).
Cox, Caroline. 1995, Glyphosate, Part 1: Toxicology and Glyphosate,
Part 2: Human Exposure and Ecological Effects, Journal of Pesticide
Reform, Vol 15, no. 3 and no. 4.
Folmar, L.C., Sanders, H.O. and Julin A.M. 1979. Toxicity of the
herbicide glyphosate and several of its formulations to fish and
aquatic invertebrates. Arch. Environ. Contam. Toxicol. 8:269-278.
Franz, J.E., (1997), Glyphosate — A Unique Global Herbicide, American
Chemcial Society, Washington D.C.
Greenpeace. “factsheets — Glyphosate Fact Sheet”, April 1997,
http://www.greenpeaceusa.org/media/f...hosatetext.htm
(Accessed 7 July 2001).
Hassan, S.A. et al. 1988. Results of the fourth joint pesticide
testing programme carried out by the IOBC/WPRS - Working group
“Pesticides and Beneficial Organisms”. J. Appl. Ent. 105:321-329.
Holdway, D.A and Dixon, D.G. 1988. Acute toxicity of permethrin or
glyphosate pulse exposure to larral white sucker (Catostomus
commersoni) and juvenile flagfish (Jordanella floridae) as modified by
age and ration level. Eviron. Toxical. Chem, 7:63-68.
Kearney, P.C. 1988. Herbicides. Marcel Dekker, Inc, New York.
Knight, S. “Herbicide Bibliography”, Glyphosate, Roundup and other
herbicides - an annoted bibliography, January 1997,
http://www.powerlink.net/fen/herb.htm (Accessed 7 July 2001).
Levesque, C.A. and Rahe, J.E. (1992), Herbicide interactions with
fungal root pathogens, with special reference to glyphosate. Annual
Review of Phytopathology v.30 (1992) p.579-602.
MacKinnon, D.S. and Freedman, B. 1993. Effects of silvicultural use
of the herbicide glyphosate on breeding birds of regenerating
clearcuts in Nova Scotia, Canada. J. Appl. Ecol. 30(3):395-406.
Pesticides Trust, “Glyphosate”, Pesticides News (issues No.33,
September 1996), http://www.pan-uk.org/pestnews/actives/glyphosa.htm
(Accessed 4 July 2001).
Piccolo, A. et al (1994), Adsorption and desorption of glyphosate in
some European soils. Journal of Environmental Science and Health,
part B, v.29, pp.1105-1115.
Author not mentioned, “ Round up”, 19 November 1997,
http://csf.colorado.edu/northwest/nw.../msg00923.html
(Accessed 7 July 2001).
Sawada, Y., Nagai, Y., Ueyama, M., and Yamamoto, I. 1988. Probable
toxicity of surface-active agent in commercial herbicide containing
glyphosate. Lancet 1(8580):299.
Servizi, J.A., Gordon, R.W., and Martens, D.W. 1987. Acute toxcity of
Garlon 4 and Roundup herbicides to salmon, Daphnia, and trout. Bull.
Environ. Contam. Toxicol. 39:15-22.
Talbot, A.R. et al. 1991. Acute poisoning with a
glyphosate-surfactant herbicide ('Roundup'): A review of 93 cases.
Human Exp. Toxicol. 10: 1-8.
Temple, W.A. and Smith, N.A. 1992. Glyphosate herbicide poisoning
experience in New Zealand. N.Z. Med. J. 105:173-174.
Tominack, R.L. et al. 1991. Taiwan National Poison Center: Survey of
glyphosate-surfactant herbicide ingestions. Clin. Toxicol. 29(1):
91-109.
U.S. Dept. of Health and Human Services. Public Health Service.
National Institutes of Health. NTP technical report on toxicity
studies of glyphosate (eas No. 1071-83-6) administered in dosed feed
to F344/N rats and B6C3F1 mice. (NIH Publication 92-3135). Toxicity
Reports Series No. 16. Research Triangle Park, NC: National
Toxicology Program.
U.S. EPA. Office of Pesticide and Toxic Substances. 1985.
Glyphosate; EPA Reg. #524-308; Mouse Oncogenicity Study. Washington,
D.C. (April 3).
U.S. EPA Office of Pesticides and Toxic Substances. 1986. Guidance
for the reregistration of pesticide products containing glyphosate.
Washington D.C (June).
United States Environmental Protection Agency (EPA), “Consumer
Factsheet on: Glyphosate”, Main Line News. 1998,
http://groups.yahoo.com/group/MainLi...age/13040.html
(Accessed 7 July 2001).
U.S Forest Service Contract, “Glyphosate-Pesticide Fact Sheet”,
Information Ventures, Inc, November 1995,
http://www.infoventures.com/e-hlth/p...e/glyphos.html ( Accessed 4
July 2001).
Wan, M.T., Watts, R.G. and Moul, D.J. 1989. Effects of different
dilution water types on the acute toxicity to juvenile pacific
salmonids and rainbow trout of glyphosate and its formulated products.
Bull. Environ. Contam. Toxicol. 43:378-385.
Wan, M.T, Watts, R.G. and Moul, D.J. 1991. Acute toxicity to juvenile
Pacific Northwest Salmonids of Basacid Blue NB755 and its mixture with
formulated products of 2,4-D, glyphosate and triclopyr. Bull.
Environ. Contam. Toxicol. 47:471-478.
World Health Organisation, United Nations Environment Programme, the
International Labour Organisation. 1994. Glyphosate. Environmental
Health Criteria #159. Geneva , Switzerland.
Yousef, M.I. et al (1995), Toxic effects of carbofuran and glyphosate
on semen characteristics in rabbits. Journal of Environmental Science
and Health, part B. v. 30p.513-534.