ToxFAQs™ for Atrazine
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This fact sheet answers the most frequently asked health questions about atrazine. For more information, you may call the ATSDR Information Center at 1-888-422-8737. This fact sheet is one in a series of summaries about hazardous substances and their health effects. This information is important because this substance may harm you. The effects of exposure to any hazardous substance depend on the dose, the duration, how you are exposed, personal traits and habits, and whether other chemicals are present.
The general population is probably not exposed to atrazine. However, exposure to atrazine may occur at farms where it has been sprayed. Atrazine may affect pregnant women by causing their babies to grow more slowly than normal. Birth defects and liver, kidney, and heart damage has been seen in animals exposed to high levels of atrazine. This chemical has been found in at least 20 of the 1,636 National Priorities List sites identified by the Environmental Protection Agency (EPA).
What is atrazine?
Atrazine is an herbicide that does not occur naturally. Pure atrazine is an odorless, white powder that is not very volatile, reactive, or flammable and that will dissolve in water.
Atrazine is used to kill weeds, primarily on farms, but has also been used on highway and railroad rights-of-way. The EPA now restricts how atrazine can be used and applied; only trained people are allowed to spray it.
What happens to atrazine when it enters the environment?
- Atrazine enters the environment primarily through spraying on farm crops.
- In soil, atrazine is taken up by the plants growing in the soil or is broken down over a period of days to months.
- It may also wash from soil into streams or groundwater where it will stay for a long time, because breakdown of the chemical is slow in water.
- If atrazine enters the air, it may be broken down by reactions with chemicals in the air, or it may adhere to particles such as dust which eventually settle out of the air.
- Atrazine does not accumulate in living organisms such as algae, bacteria, clams, or fish.
How might I be exposed to atrazine?
- Most people are not exposed to atrazine on a regular basis.
- It is rarely found in food samples; when found, it is only at very low levels.
- Farm workers, chemical sprayers, and people who work in factories that make atrazine may be exposed.
- People may also be exposed to atrazine by digging in dirt that has atrazine in it.
- Individuals may also be exposed by drinking water from wells that are contaminated with the herbicide.
How can atrazine affect my health?
Liver, kidney, and heart damage has been
observed in animals exposed to atrazine; we do not know if
this would also occur in humans. Atrazine has also been shown
to cause changes in blood hormone levels in animals that affected
ovulation and the ability to reproduce. These effects are
not expected to occur in humans because of specific biological
differences between humans and these types of animals.
How likely is atrazine to cause cancer?
Available information is inadequate to
definitely state whether atrazine causes cancer in humans.
There are limited human and animal data that suggest that
there may be a link between atrazine exposure and various
types of cancer. A Cancer Assessment Review Committee (CARC)
sponsored by EPA has classified atrazine as not likely to
be carcinogenic to humans. The International Agency for Research
on Cancer (IARC) has determined that atrazine is not classifiable
as to its carcinogenicity to humans.
How can atrazine affect children?
Little information is available regarding
the effects of atrazine in children. It is likely that the
health effects seen in children should be similar to the effects
seen in adults. We do not know whether children differ from
adults in their susceptibility to atrazine.
A few studies are available that suggest
that atrazine could affect pregnant women by causing their
babies to grow more slowly than normal or by causing them
to give birth early. However, the women in these studies were
also exposed to other chemicals that may have caused or contributed
to these effects. In pregnant animals, exposure to atrazine
causes a decrease in fetal growth and birth defects. Exposure
to high levels of atrazine during pregnancy caused reduced
survival of fetuses. It is unclear whether or at what level
of exposure this might occur in humans.
How can families reduce the risk of exposure to
- The general population is not likely to be exposed to
large amounts of atrazine. Populations living in the areas
where atrazine is used on crops, however, may be exposed
to greater amounts of atrazine. Therefore, staying away
from fields that have been recently sprayed may reduce exposure.
- Atrazine may be washed from fields where it is sprayed
into streams and rivers or may migrate into wells used for
drinking and bathing. In areas of high atrazine use, individuals
should avoid swimming in or drinking from contaminated water
sources and may desire to have personal well water tested
for the presence of atrazine.
- Children should avoid playing in soils near uncontrolled
hazardous waste sites where atrazine may have been discarded.
Is there a medical test to show whether I've been
exposed to atrazine?
Atrazine can be detected in your blood
and some other body tissues within 24 to 48 hours after your
last exposure. These tests are not usually available at your
doctors office, but your doctor can send the samples to a
laboratory that can perform the tests. None of these tests,
however, can predict whether you will experience any health
Has the federal government made recommendations to
protect human health?
The EPA has set a maximum amount of atrazine in drinking water of 0.003 milligrams of atrazine per liter of drinking water (0.003 mg/L).
The Occupational Safety and Health Administration (OSHA) has set a limit of 5 milligrams of atrazine per cubic meter of workplace air (5 mg/m3) for an 8-hour workday and 40-hour work week.
The EPA has determined maximum levels allowed in foods of 0.02-15 parts atrazine per million parts of food (0.02-15 ppm).
Agency for Toxic Substances and Disease Registry (ATSDR). 2003. Toxicological Profile for Atrazine. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.
Where can I get more information?
If you have questions or concerns, please contact your community or state health or environmental quality department or:
For more information, contact:
Agency for Toxic Substances and Disease Registry
Office of Innovation and Analytics, Toxicology Section
4770 Buford Highway
Chamblee, GA 30341-3717
Phone: 1-800-CDC-INFO 888-232-6348 (TTY)
Email: Contact CDC-INFO
ATSDR can also tell you the location of occupational and environmental health clinics. These clinics specialize in recognizing, evaluating, and treating illnesses resulting from exposure to hazardous substances.