Atrazine and its effects in the
United States
Jennifer Yu, Kyle Schultz, Ambara
Adan
WHAT IS ATRAZINE??
• Atrazine is one of the most used
herbicide/pesticide used for growing corn,
sugarcanes, other crops and as well as
landscaping
• Atrazine kills weeds by blocking
photosynthesis but does not harm crop
production (and it’s pocket friendly so farmers
love this stuff)
SO…what does it have to do with me?
• Human beings are exposed to atrazine in our
food, water and air.
• Atrazine is an endocrine disruptor and is
causing abnormal hormone function in frogs,
fish, rats and even human
• Humans and frogs have similar physiology
• Potential causing health problems to humans
• Creates massive contamination problems
Decreasing biodiversity
•
• Exposure to atrazine, depending on the amount the frogs are
exposed to, can lower or eliminate testosterone and increase
estrogen, turning frogs hermaphroditic
• Changes frogs behavior
• Lack of interest to mate and not able to reproduce.
• Decrease of evolutionary fitness
• Possible extinction in future which is not good for ecosystem.
SO…what does it have to do with me?
• Human beings are exposed to atrazine in our
food, water and air.
• Atrazine is an endocrine disruptor and is
causing abnormal hormone function in frogs,
fish, rats and even human
• Humans and frogs have similar physiology
• Potential causing health problems to humans
• Creates massive contamination problems
Contamination of
Ground and surface
water
• The Atrazine rap
•
• https://www.youtube.com
/watch?v=3MxrH4lN0-A
•
•
•
•
•
Atrazine is a chemical with
mobility
Once sprayed on weed, it slowly
absorbed into the soil and
eventually contaminating ground
water
Runoff from rain transports
Atrazine to near by water such as
lakes, ponds, rivers and
contaminating surface water
Rain
Atrazine is most commonly found
chemical in water.
If were drinking water with
atrazine….what will happen to us?
Resolution?
• In october 2003, Europe
banned the Atrazine due to
water contamination.
• Banning the atrazine is the
best solution for the U.S but
it doesn’t completely solve
the problem and is costly
How Does Atrazine Enter the Environment?
Used as herbicide for numerous crops
-Corn,sugarcane, sorghum
-Most Heavily used in Corn in the US
Spray application with a high chance of runoff (especially after rain)
Non-point pollution sources that build up as they flow down
the watershed
-Atrazine flows and contaminate streams rivers and groundwater and has a
half life in water of 6 months allowing concentration levels to build past EPA
standards in some locations (Quansah, 2008)
(Hayes, 2002)
(Solomon, 1996)
(Solomon, 1996)
(Solomon, 1996)
(Hayes, 2002)
Source of the Environmental Problem…
• There’s up to 40 parts per billion (ppb) of
atrazine in precipitation from agricultural runoffs (Hayes et. al 2002).
– Atrazine, an endocrine disrupter was the most
commonly used herbicide in 1997 (EPA).
– The herbicide applications had 76 million pounds
of active ingredient (EPA).
– Used for over 40 years and in 80 countries (Hayes et.
al 2002).
Source of the Environmental
Problem…Explained through Experimentation
• Tyrone B. Hayes discovered that atrazine
feminizes the male African clawed frogs
physically.
– Genetically they were still males, but had female
reproductive structures and functions (Hayes et al.
2006).
• This later made people realize if it effects frogs, maybe
it effects humans too.
African clawed frogs (Xenopus laevis)
Chromosomes:
Female- ZZ
Male- ZW
• kind of opposite to humans (male:XY female:XX)
– May be the reason that mammals do not change sex when exposed to
atrazine, but it does have other negative side effects.
• Similar to the frog DNA they used in Jurassic Park, which makes no sense since
chickens have a greater relationship with dinosaurs, but the dinosaurs in that
movie were Protogyny and not Protandry.
• African clawed frogs show sexual dimorphism: females are larger
• You can induce the release of eggs in females by injecting them
with human chorionic gonadotropin (hCG) or luteinizing
hormone-releasing hormone (LHRHa) (Byrne 2010).
African clawed frogs (Xenopus laevis)
• An atrazine-induced female frog (a genetic male) is shown
(bottom) copulating with an unexposed male sibling. This union
produced viable eggs and larvae that survived to metamorphosis
and adulthood. Yet, because both animals were genetic males, the
offspring were all males (Sanders 2010). (Tyrone Hayes photo
posted on UC-Berkeley News Center)
How Atrazine affects frogs
• Males had 10-fold decrease in testosterone
levels when they were exposed to 25 ppb of
atrazine (Hayes et. al 2002).
• Atrazine induces aromatase (enzyme
responsible for synthesis of estrogen) and
converts testosterone (male hormone) to
estrogen (female hormone) (Hayes et. al 2002).
How Atrazine affects frogs
• Hayes finding suggest that atrazine could
impair other amphibians to leave viable
offspring, when there is a higher ratio of
females than males.
– This will decrease the biodiversity in of
amphibians.
– But since there’s an increase in females, which
means that inbreeding can occur; it increases
the frogs’ coefficient of relatedness, which
decreases genetic variation.
Solutions
Ideal Solutions
- Push to ban atrazine untill effects are fully understood or remedied
-Push for reduction
- More efficient water treatment plants (Tertiary Treatment)
-Switch to a safer herbicide alternative
(Not Feasible in the short term because of time and money)
Monitoring and Improved Farming Techniques
Types of Monitoring
Water Erosion Prediction Project (WEPP)
-Model to simulate soil loss from erosion
Soil and Water Assessment Tool (SWAT)
-predicts sediment and agricultural chemical yields
Agricultural Drainage and Pesticide Transport (ADAPT)
-model for determining agricultural migration into groundwater
Groundwater Loading Effects of Agricultural Management Systems
(GLEAMS)
-assess pesticide loss to ground and surface water
(Quansah, 2008)
No Till Vs. Conventional Farming
No till farming is a farming practice that is more
environmentally friendly and helps crop yields for
farmers
-Helps to prevent soil erosion and nutrient leaching
-Retains more nutrients in the soil usable by crops
-Reduces C02 Emissions
Study done by J Quansah looks at the effect of no till farming on
Atrazine through monitoring stations and satellite imagery.
(Quansah, 2008)
(Quansah, 2008)
(Quansah, 2008)
References:
•
Byrne, Phillip G., and Aimee J. Silla. "Hormonal induction of gamete release, and in-vitro fertilisation, in the critically
endangered Southern Corroboree Frog, Pseudophryne corroboree." Reprod Biol Endocrinol 8 (2010): 144.
•
EPA. "Atrazine Chemical Summary." U.S. EPA, Toxicity and Exposure Assessment for Children’s Health. Environmental
Protection Agency, 24 Apr. 2007. Web. 18 Apr. 2014. <http://www.epa.gov/teach/chem_summ/Atrazine_summary.pdf>.
•
Hayes, Tyrone B., et al. "Hermaphroditic, demasculinized frogs after exposure to the herbicide atrazine at low ecologically
relevant doses."Proceedings of the National Academy of Sciences 99.8 (2002): 5476-5480.
•
Hayes, Tyrone B., A. Ali Stuart, Magdalena Mendoza, Atif Collins, Nigel Noriega, Aaron Vonk, Gwynne Johnston, Roger
Liu, and Dzifa Kpodzo. "Characterization of Atrazine-Induced Gonadal Malformations in African Clawed Frogs (Xenopus
Laevis) and Comparisons with Effects of an Androgen Antagonist (Cyproterone Acetate) and Exogenous Estrogen (17βEstradiol): Support for the Demasculinization/Feminization Hypothesis." National Center for Biotechnology Information.
U.S. National Library of Medicine, 24 Jan. 2006. Web. 20 Apr. 2014.
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1874169/>. Sanders, Robert. "Pesticide Atrazine Can Turn Male Frogs into
Females." UC Berkeley NewsCenter. UC Berkeley, 1 Mar. 2010. Web. 20 Apr. 2014.
<http://newscenter.berkeley.edu/2010/03/01/frogs/>.
-Solomon, Keith R., David B. Baker, R. Peter Richards, Kenneth R. Dixon, Stephen J. Klaine, Thomas W. La Point, Ronald J.
Kendall, Carol P. Weisskopf, Jeffrey M. Giddings, John P. Giesy, Lenwood W. Hall, and W. Marty Williams. "Ecological
Risk Assessment of Atrazine in North American Surface Waters." Environmental Toxicology and Chemistry15.1 (1996): 3176. Print
Con’t...
-Quansah, J. E., B. A. Engel, and I. Chaubey. "Tillage Practices Usage in Early Warning Prediction of Atrazine Pollution."
Transactions of the ASABE51.4 (2008): 1311-321. Print.
-Hayes, Tyrone, Kelly Haston, Mable Tsui, Anhthu Hoang, Cathryn Haeffele, and Aaron Vonk. "Atrazine-Induced
Hermaphroditism at 0.1 Ppb in American Leopard Frogs (Rana Pipiens): Laboratory and Field Evidence."Environmental
Health Perspectives 111.4 (2002): 568-75. Print.