Presentation on theme: "The Effects of Atrazine Application to the Environment"— Presentation transcript:
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 endedBio-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 industryAtrazine 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 useIt 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 useIt 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 soilDegradation 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-adaptedHas 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 soilsNitrogen 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 soilMovement is limited to soil layers of minimal depth.Sandy soil movement reaches depths greater than clay and silty soil.
13 Atrazine in the airHighest Concentration is in Summer, Lowest Concentration is in WinterRemains 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 effectsOnce 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 waterMinimal amounts from food
19 Chemical Affects Atrazine has aromatic activities Estrogen levels reduceUnderlying 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 coordinationMetal and Physical skills
22 Long Term Exposure Increase Risk of Ovarian Cancer Increase Risk of Breast CancerIncrease InfertilityIncrease Reproductive Disorder
23 Modeling with Stella Model Logic Method to find Atrazine sink Predict environmental degradationCompare soil, Air, Water degradationInterpretation of Stella
25 Atrazine In Soil Outflows Inflows Biological Degradation, Half-life 42.5 daysErosion, 55% immediately lostEvaporation, Half-life 97 daysInflowsApplication of 34 million kgCondensation from Air
26 Atrazine In Air Inflows Outflows Evaporation, Half Life 97 days initial applicationsprayingOutflowsOxidation, Half life 0.11 DaysPhotodegradation, Half life daysCondensationTake into account 30% of Earth land
27 Atrazine In Water Inflows Outflows Erosion, 55% Condensation, F(x) of AirOutflowsSedimentation, Half life 14 daysAquatic Degradation, Half life 3.2 daysIngestion
29 Water as the Sink Air is not:Degradation less than 1 day Soil, initially a sink, long run NOThe Data suggest that water is the sinkthe sink is draining, does not acumulateWarning: decrease with one application after years steady increase
30 Degradation Routes Air initial spike degrades quickly Water Spikes later and degrades slowerSoil 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 AtrazineIndicates steadily rising levels of ATR over time with yearly application
32 Demonstration Atrazine Movement Through the Environment Begins with application, mainly crops
33 Stella AgreementStella agrees with the literature in that atrazine does not persist relatively long in the environmentStella is also in agreement in terms of water being the final sink.
34 DemonstrationIt then works its way to the water supply, by runoff and other mechaismsthen it follows tributaries and streamsEnds up in Large rivers, Lakes and Oceans
35 ConclusionsBanning 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.