1. Chapter 23
The Pesticide Dilemma

2. What is a Pesticide? First-Generation Pesticides
Inorganic compounds (e.g., lead, mercury)
Botanicals (e.g., nicotine, pyrethrin)
Pyrethrin is used against mosquitos
Nicotine has been banned as pesticide since 2001

3. Pyrethrin is derived from chrysanthemum flowers.

4. What is a Pesticide? Second-Generation Pesticides
Synthetic botanicals (e.g., pyrethroids)
DDT

5. What is a Pesticide? The Major Groups of Insecticides
Chlorinated hydrocarbon (e.g., DDT)
Organophosphates (e.g., malathion) The chemicals in this class kill insects by disrupting their brains and nervous systems. Unfortunately, these chemicals also can harm the brains and nervous systems of animals and humans
Carbamates (e.g., carbaryl)

6. SHORT-TERM HEALTH HAZARDS
- The carbamate pesticides listed above are highly poisonous chemicals, with the exception of carbaryl
(SEVIN), which is moderately poisonous.
- All these chemicals can be absorbed through the skin, especially through cuts and scratches, so direct contact
should be avoided.
- Carbamates are highly irritating to the eyes.
LONG-TERM HEALTH HAZARDS
- Carbamates are generally not considered to be cancerous, with two exceptions. Carbaryl (SEVIN) and
carbofuran (FURADAN) can mix with other elements in the stomach to form possible cancerous chemicals.
- Some carbamates, such as carbofuran (FURADAN), have been shown to cause birth defects or reproduction
problems in laboratory animals. Further studies are required for specific compounds.
- Carbamates do not accumulate and persist in the body.

7. What is a Pesticide? The Major Kinds of Herbicides
Selective herbicides
(e.g., 2,4-D – kills broad-leaved plants)
Nonselective herbicides
(e.g., glyphosate, aka: Round-UpTM)

8. Did somebody
say “roundup”?
I love horsies!!!

9. Benefits and Problems with Pesticides
Benefit: Disease Control
Location of malaria

10. Benefits and Problems with Pesticides
Benefit: Crop production
Farmers save ~$3 - $5 in crops for every $1 invested into pesticides
Mo money, mo money, mo money!!!

11. Benefits and Problems with Pesticides
Problem: Evolution of Genetic Resistance
# of species exhibiting genetic resistance to pesticides

12. Benefits and Problems with Pesticides
Problem: Evolution of Genetic Resistance
Creates a pesticide treadmill
Kills most pests
Resistant survive
Numbers increase
INCREASE
Pesticide application
EVEN MORE
New population genetically resistant

13. Benefits and Problems with Pesticides
Problem: Evolution of Genetic Resistance
Resistance Management
Create a “refuge” (no pesticide applied)
Avoid repeated use of same pesticide

14. Benefits and Problems with Pesticides
Problem: Imbalances in the Ecosystem

15. California red scale was introduced into California between 1868 and 1875, apparently on citrus seedlings from Australia. The scale insect is native to Southeast Asia but has been transported on citrus seedlings to all arid and semiarid regions of the world where citrus is grown. It occurs in all of California's citrus growing areas.

16. Benefits and Problems with Pesticides
Problem: Imbalances in the Ecosystem
Creation of New Pests

17. Benefits and Problems with Pesticides
Problem: Persistence, Bioaccumulation, and Biological Magnification
Biomagnification of DDT

18. Benefits and Problems with Pesticides
Problem: Mobility in the Environment

21. Risks of Pesticides to Human Health
Short-term Effects of Pesticides
Handling of food with pesticide residue

22. There are two types of exposure: chronic and acute, like me!!!
Move over Bowles, that’s my line!!!

23. Risks of Pesticides to Human Health
Short-term Effects of Pesticides
Case-in-Point: The Bhopal Disaster
40 tons of methyl isocyanate gas released
600,000 people exposed
2,500 immediately killed
2,500 more killed through time
50,000-60,000 have serious health problems

24. Risks of Pesticides to Human Health
Long-term Effects of Pesticides
Potentially higher risk of cancer
Sterility
Miscarriage / birth defects
Potentially higher risk for Parkinson’s disease

25. Alternatives to Pesticides
Using Cultivation Methods to Control Pests
Interplant mixtures of plants
Strip cutting
Planting, fertilizing, and irrigating at proper time
Crop rotation

26. Alternatives to Pesticides
Biological Controls
Using naturally occurring diseases, parasites, or predators to control a pest
Pheromones and Hormones
Use pheromones to attract insects to traps
Synthetic hormones induce abnormal development
Reproductive Controls
Sterile-male technique – inundate pest population with large numbers of sterile males

27. Alternatives to Pesticides
Genetic Controls
Using Genetically Modified plants (GMOs)
Case-in-Point: Bt, Its Potential and Problems
Genetically modified corn to produce Bt toxin
Potential problem: may affect non-target species, such as monarch butterfly
Quarantine

28. Alternatives to Pesticides
Integrated Pest Management

29. Alternatives to Pesticides
Integrated Pest Management
IPM introduced
Rice Production in Indonesia

30. Alternatives to Pesticides
Irradiating Foods
Predominantly used on meats
Kills many microorganisms
This really makes Zombies! No listen to me, they will take over the world, they already live in the oceans!!!

31. Laws Controlling Pesticide Use
Food, Drug, and Cosmetics Act (1938)
Pesticide Chemicals Amendment (1954)
Delaney Cause (1958)
Federal Insecticide, Fungicide, and Rodenticide Act (1947)
Estimates of Risk of Cancer from Pesticide Residue

32. Laws Controlling Pesticide Use
Food, Drug, and Cosmetics Act (1938)
Pesticide Chemicals Amendment (1954)
Delaney Cause (1958)
Federal Insecticide, Fungicide, and Rodenticide Act (1947)
Food Quality Protection Act (1996)

33. The Manufacture and Use of Banned Pesticides
Some US companies still make banned or seriously restricted pesticides and export the product.
This can potentially lead to the importation of food tainted with banned pesticides
Soylent Green is People!

34. The Manufacture and Use of Banned Pesticides
The Global Ban of Persistent Organic Pollutants