1. The Effects of Atrazine Application to the Environment
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.
-atrazine is a 6-carbon S-chlorotriazine
-Pure atrazine is a man-made odorless white powder that is not naturally occurring, it is used in a powder, liquid and granular form.
-Atrazine has been known to persist in soil and water long after application has ended
Bio-degradation is theoretically possible but studies have found that atrazine is still persistant in the environment.
Atrazine has been seen to Bio-accumulate in Zebra fish embryo’s with a BCF of 19

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).
-Atrazine is a selective herbicide used primarily as a broadleaf weed and grass controller in many agricultural settings.
-Atrazine is usually applied in the spring or summer months because in order to be activated atrazine must be dissolved in water and enter the target plants root system.
-this causes problems because of the large amount of rain in the spring which can make it mobile and wash it into another median.
-Atrazine is a restricted use pesticide(rup) this means that in order to use atrazine a farmer must go through a yearly certification process where that person is liscenced by the state.

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
-In small agricultural ponds with intense run-off can obtain levels of 1mg/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.
-Atrazine was designed to reduce the CO2 fixation in selected plants by blocking photosynthesis.
-Crop plants aren’t effected when they are induced with Glutathione S-transferences (GST) which is one mechanism for detoxifying the Atrazine that is in contact with the plants by breaking it down before it can disrupt photosynthesis.
Atrazine works well as both a pre- and post emergent herbicide- due to its ability to block photosynthesis when in contact with non crop plants.

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.
-The complete effects of Atrazine’s ability to block normal functions of plants and animals (expecially humans) is unknown due to a lack of data on humans because of obvious morality issues that would be involved in such a study.
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 this is due to diverse conditions that are present in the system .
Because of our extensive reliance on herbicides such as Atrazine in order to continue to produce enough food to support our planet going to need to find better more biodegradable pesticides or we will have to cut back on our use of the currently used ones such as atrazine.

8. Outline of Atrazine’s course through the environment
-Because of the application techniques of spraying herbicides broadly on the fields over the soil the first thing affected is the soil
-From here it can be evaporated into the air or stay in the plants washed into the surface water

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 Non-adapted
Has had atrazine applied on a consistent basis.
Non-adapted
Has not had atrazine applied to the soil.
Adapted soils have a higher degradation rate due to a higher microbial population. Almost like the atrazine is feeding the microbial and causing the population to grow. Dealkylation dehalogenation.
Non-adapted soils has a lower degradtion rate. Lower microbial population.

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.
Addition of organic amendments stimulates the microbial biomass, accelerates biodegradation.

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.
In the spring Atrazine levels are highest. -most of the atrazine applied to kill pre-emergent plants ends up as run-off in local surface water.
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.
once in surface water it degrades very slowly it can have a half life of >200 days.
-though atrazine does biodegrade slow in water sources there is a possibility for special bacteria to be grown that survive off of atrazine as their only energy source. But unfortunately the natural systems are far more complex and at the present time such solutions are unrealistic.

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
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 effects, Neurological effects and reproductive 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.
-Atrazine disrupts pregnancy by inhibiting normal ovulatory surges
.-Which include a release in luteinizing hormone (LH) and Prolactin (PRL) and testosterone(in males).
Inhibiting the release of (LH) with 30-50mg/kg of atrazine causes the pregnancy to be terminated.
Inhibiting the release of (PRL) causes the cancerous mammary gland tumors.
Inhibitng the release of testosterone can slow down the normal development of the reproductive track.
In zebra fish embryos the process of detoxifying the atrazine can use up the available yolk and harm the fish’s development.

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

27. Atrazine In Water Inflows Outflows 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.

36. THANK YOU