PESTICIDES

1
PESTICIDES

• a discussion of the health hazards
• associated with chemicals
• used for control of various pests

2
General Considerations

• Substances used to kill unwanted pests
• Algae-, herb-, insect-, rodent-
• Selective toxicities
• Resistance of target species
• Bioconcentration
• Environmental persistence

3
Rodenticides

• Red Squill (extract from sea onion)
• Sodium fluoroacetate
• Thallium salts
• Norbormide
• Warfarin
• Fumigants (MeBr, phosphine, etc.)

4
Insecticides

• CHLORINATED HYDROCARBONS
• Organic based structure
• Chlorine in the base molecule
• Unknown toxic action in the insects
• Moderate-to-long persistence
• Accumulation in fatty tissue
• Toxic action on CNSgttremorsgtdeath
• Some are cancer suspects

5
Alternatives to Insecticides

• Other chemicals
• Bacterial insecticides
• Growth regulators
• Sex attractants
• Sterile males
• Insect-resistant crops
• Questioned effectiveness of insecticides

6
Herbicides

• Usually used to kill broad-leaf weeds and/or
  defoliate
• Most work on basis of action on plant hormones
  (auxins)
• Examples 2,4-D and 2,4,5-T
• Highly toxic byproduct dioxin
• Toxicities of dioxin