What
is atrazine?
Atrazine
is an herbicide used to control broadleaf and grassy weeds.
Atrazine is mainly applied to corn and soybean crops, but is also
used on sorghum, sugarcane, pineapple, and Christmas tree farms.
This pesticide is a white crystalline solid organic compound that
is available in many forms as a dry flowable, flowable
liquid, water dispersible granular liquid, and a wetable powder.
Trade names for atrazine include aatrex and atratol, and atrazine
is in the family of triazines.4,5
What
is the distribution of atrazine?
Atrazine
is one of the most heavily used herbicide in the United States.4
In 1990, over 64 million acres of cropland were treated with
atrazine. This herbicide is
used mainly in Indiana, Illinois, Indiana, Iowa, Kansas, Missouri,
Nebraska, Ohio, Texas and Wisconsin.
In 1997 in Portage County, WI, atrazine was applied to 21,318 acres
at 0.75 lbs/A/yr (total-15,988 lbs) for field corn, and 5,200 acres at
0.78 lbs/A/yr (total-4,056 lbs) for sweet corn.3
Atrazine
is carried by water into the soil and other water bodies.
Microbial activity and other chemicals breakdown atrazine in soil
and water, especially in alkaline conditions.
Occasionally, atrazine may bind to soil particles, but it generally
leaches to groundwater. Sunlight and evaporation do not reduce or affect atrazine.4,5
What
is the drinking water regulation?
The
Safe Drinking Water Act of 1974 requires that the EPA (Environmental
Protection Agency) set safe drinking water standards for chemicals in
drinking water. Atrazine has
entered surface water and groundwater mainly through runoff from
herbicides used in row crops and wastewater from manufacturing facilities.
This potential for water contamination prompted the regulation of
atrazine in 1992 with both the Maximum Contaminant Level Goal (MCLG) and
Maximum Contaminant Level (MCL) being set at 3 parts per billion (ppb).
Between 1993 and 1995, public water supplies were required to
collect water samples every three months for one year and test for
atrazine. If atrazine was
above 1ppb, then testing had to be continued every three months.
If atrazine was above 3ppb, then the water was treated with
granular activated charcoal. Since
its regulation, only licensed applicators may purchase and apply atrazine.4
Atrazine Levels in Portage County Well Water Samples
Where
is the water contaminate?
Despite restrictions, atrazine has contaminated groundwater. In fact, it was the second most frequently detected pesticide in the EPA’s National Pesticide in Drinking Water Wells Survey.4 Atrazine exceeds the MCL of 3ppb in the following states: Delaware, Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, New York, and Wisconsin.4
In
Portage County, 40% of the private wells tested have a detection of
atrazine (small red dots on map).
Of this 40%, 3% exceed the Drinking Water MCL of 3 ppb for atrazine
(large red dots on map).1,2 The pink shaded areas on the
map indicate moratorium areas where the use of atrazine is banned.
What
are the health impacts?
Studies
have shown atrazine to be slightly to moderately toxic to humans and
animals, especially aquatic life. Atrazine
can be absorbed orally, through the skin, and inhaled. The symptoms mimic many other illnesses.
They include abdominal pain; diarrhea; vomiting; and irritation to
the eye, skin, and mucus membranes. Short-term
exposure can result in congestion of heart, lungs, kidneys; low blood
pressure; muscle spasms; weight loss; and damage to adrenal glands.
A short-term exposure is defined as exposure above the MCL for
short periods of time. Long
term exposure can result in weight loss; cardiovascular damage; retinal
and some muscle degeneration; and cancer.
A long-term exposure is defined as a lifetime exposure above the
MCL.4,5
References
and More Information
1.
Kraft, George & Mechenich, Dave.
(2000, January 1). Portage
County Groundwater Conditions. Stevens
Point, WI: Groundwater Management Subcommittee and Public
Involvement/Education Subcommittee of the Portage County Groundwater
Citizens Advisory Committee for Portage County Planning and Zoning
Department.
2.
http://www.uwsp.edu/water/portage/undrstnd/landuse.htm
3.
http://www.uwsp.edu/water/portage/undrstnd/pestpc.htm
4.
http://www.epa.gov/safewater/dwh/c-soc/atrazine.html
5.
http://pmep.cce.cornell.edu/profiles/extoxnet/24d-captan/atrazine-ext.html
6.
http://www.ianr.unl.edu/pubs/pesticides/g1158.htm
7.
http://www.epa.gov/pesticides/reregistration/atrazine/
8.
http://www.scorecard.org/chemical-profiles/summary.tcl?edf_substance_id=1912-24-9
9.
http://www.cjnetworks.com/~sccdistrict/bestatra.htm
10. http://www.ianr.unl.edu/pubs/water/g1299.htm
11. http://www.junkscience.com/news/atrazine.html