Pesticides

1
Pesticides
2
Pesticides

• Used to get rid of pests of all kinds.
• If it is toxic to other life forms, it may be
  toxic to us.
• Also may be toxic to other organism that we dont
  want them to harm.
• Must be used with care
• 20,000/year in US receive emergency medical care
  from perceived or actual exposure
• 30/year die from above

3
(No Transcript)
4
Pesticides

• Most important are insecticides, herbicides, and
  fungicides
• Persistent pesticides remain in environment and
  spread.
• Most recent research has been for short-lived
  pesticides
• Most persistent ones have been removed from use.
• Like DDT

5
(No Transcript)
6
(No Transcript)
7
DDT

• Hailed as miraculous in 1945 by Sir Winston
  Churchill
• Saved millions of lives
• Malaria mosquitoes
• Yellow fever mosquitoes
• Typhus body lice
• Fleas bubonic plague
• Banned in the late 1960s in developed countries
• Still being used in underdeveloped countries
• Still saving millions of lives/year imported
  foods?

8
Organochlorine insecticides
9
Bioaccumulation bioconcentration
biomagnification
More soluble in fats than in water
.000003 ppm in water
10
Organophosphate and CarbamateInsecticides

• Non-persistant break down quickly in the
  environment.
• Dont bioaccumulate
• More immediately toxic to humans and mammals
• Examples
• Malathion will soon be restricted
• Diazinone no longer available

11
Pyrethrin, an natural insecticide
Most unstable in sunlight
12
H23 C10

• 24 - 27, 29, 30, 63, 64, 66, 69, 70, 72, 87, 88