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 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? The Atrazine rap /watch?v=3MxrH4lN0-A

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)

(Hayes, 2002)

Source of the Environmental Problem… There’s up to 40 parts per billion (ppb) of atrazine in precipitation from agricultural run- offs (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)

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 Web. 18 Apr 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): 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 (17β- Estradiol): Support for the Demasculinization/Feminization Hypothesis." National Center for Biotechnology Information. U.S. National Library of Medicine, 24 Jan Web. 20 Apr Sanders, Robert. "Pesticide Atrazine Can Turn Male Frogs into Females." UC Berkeley NewsCenter. UC Berkeley, 1 Mar Web. 20 Apr 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): 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): 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 (2002): Print.