The Effects of Atrazine Application to the Environment. By: Perry Loken, Tim Weisbrod, Nick Taylor, Sara Schmidt

1. The Effects of Atrazine Application to the Environment.By: Perry Loken, Tim Weisbrod, Nick Taylor, Sara Schmidt

2. What is Atrazine? • Atrazine is a 6-carbon S-chlorotriazine. • Atrazine is the most widely used S-triazine. • Other S-triazines used as herbicides are Symazine and cyromazine. • Atrazine is not very volatile, reactive or flammable but dissolves readily in water.

3. How Atrazine is released into the environment. • Atrazine is a selective herbicide used primarily in the agriculture industry • Atrazine is primarily applied to corn, sorghum and sugar cane. • Atrazine is a Restricted Use Pesticide (RUP).

4. Amounts of Atrazine released into the environment. • In 1993 the total amount of atrazine used in the whole country was 35,000 tons. • Atrazine usage have been increasing steadily since the 1960’s to the current level of 70,000-90,000 tons per year. • Environmental levels of atrazine in countries that use it average 5ug/L

5. Map of Atrazine application by agriculture in the U.S.

6. How Atrazine Works • Atrazine was designed to block photosynthesis. • Crop plants are able to detoxify the atrazine. • Atrazine works well as both a pre- and post emergent herbicide.

7. Why Atrazine may be a threat to the environment • The complete effects of Atrazine’s ability to block normal functions of plants and animals (expecially humans) is unknown. • Atrazine is being found in surface and drinking water reserves in areas of atrazine use • It takes considerable time to biodegrade out of the an aqueous system. • Because of our extensive reliance on herbicides.

8. Outline of Atrazine’s course through the environment

9. Atrazine in the soil • Degradation effects of Atrazine while it is in the soil. • Microbial degradation is the principle mechanism. • The kinetics is based on the nitrogen avalibility in the soil.

10. Application history • Two types of fields • Adapted • Has had atrazine applied on a consistent basis. • Non-adapted • Has not had atrazine applied to the soil.

11. Nitrogen rich soils • Nitrogen rich soils contain nitrogen molecules that are easier for the microbial to break down. • So Atrazine will be less likely attacked. • If nitrogen is deficient, then Atrazine would be a source of nitrogen for the microbial.

12. Movement through the soil • Clay and silty soil • Movement is limited to soil layers of minimal depth. Sandy soil movement reaches depths greater than clay and silty soil.

13. Atrazine in the air • Highest Concentration is in Summer, Lowest Concentration is in Winter • Remains in the air more in enclosed areas

14. Atrazine run-off to surface water • In the spring Atrazine levels are highest. • Most of the Atrazine in the soil eventually runs off into surface water. • Once in surface water it can be transported long distances before it has time to degrade.

15. Atrazine’s effect on animals • Once in surface water, atrazine is in direct contact with many species which drink or live in the water. • Atrazine does not bioaccumulate up the food chain. • The major effects of atrazine on animals are: Endocrine/Reproductive effects and Neurological effects

16. Endocrine and Reproductive Effects • Atrazine disrupts pregnancy by inhibiting normal ovulatory surges. • Which include a release in luteinizing hormone (LH), Prolactin (PRL) and testosterone (in males). • Also atrazine has been known to cause detoxification problems.

17. Nerveous system problems • Atrazine effects the Purkije cells of the nerveous system. • Cellular activity is lowered by 50% in 60 minutes. • The exact mechanism of this is unknown. • Atrazine causes motor disorders in animals.

18. Human Exposure • 2-3 million people are exposed • 0.2 ppb exposed to in drinking water • Minimal amounts from food

19. Chemical Affects • Atrazine has aromatic activities • Estrogen levels reduce • Underlying reason for hormonal disruption and tumor promoting properties

20. The Future • Womb Exposure • Suffer permanent brain defects • Breast Feeding Exposure

21. Children • Sonora, Mexico • Compared preschoolers that were exposed to Atrazine to the students that were not. • Differences is: • Hand-eye coordination • Metal and Physical skills

22. Long Term Exposure • Increase Risk of Ovarian Cancer • Increase Risk of Breast Cancer • Increase Infertility • Increase Reproductive Disorder

23. Modeling with Stella • Model Logic • Method to find Atrazine sink • Predict environmental degradation • Compare soil, Air, Water degradation • Interpretation of Stella

24. Model

25. Atrazine In Soil • Outflows • Biological Degradation, Half-life 42.5 days • Erosion, 55% immediately lost • Evaporation, Half-life 97 days • Inflows • Application of 34 million kg • Condensation from Air

26. Atrazine In Air • Inflows • Evaporation, Half Life 97 days • initial applicationspraying • Outflows • Oxidation, Half life 0.11 Days • Photodegradation, Half life 0.796 days • Condensation • Take into account 30% of Earth land

27. Atrazine In Water • Inflows • Erosion, 55% • Condensation, F(x) of Air • Outflows • Sedimentation, Half life 14 days • Aquatic Degradation, Half life 3.2 days • Ingestion

28. Atrazine Movement

29. Water as the Sink • Air is not:Degradation less than 1 day • Soil, initially a sink, long run NO • The Data suggest that water is the sink • the sink is draining, does not acumulate • Warning: decrease with one application after years steady increase

30. Degradation Routes • Air initial spike degrades quickly • Water Spikes later and degrades slower • Soil initial spike but degrades out

31. Future Projection • Projected to 2020 • It can be seen that it would take until 2012 or 22 years to be nearly rid of Atrazine • Indicates steadily rising levels of ATR over time with yearly application

32. Demonstration • Atrazine Movement Through the Environment • Begins with application, mainly crops

33. Stella Agreement • Stella agrees with the literature in that atrazine does not persist relatively long in the environment • Stella is also in agreement in terms of water being the final sink.

34. Demonstration • It then works its way to the water supply, by runoff and other mechaisms • then it follows tributaries and streams • Ends up in Large rivers, Lakes and Oceans

35. Conclusions • Banning atrazine would decrease the environmental problem but could increase health and environmental risks. • Corn and Sorghum crop yields would be reduced. • The banning would increase the use of atrazine alternatives, which are less well understood. • A better plan might be to find alternative methods of crop management in order to get the best yeilds with the smallest amount of pesticides.

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