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1. A.P. Environmental Science Historical Environmental Damage of DDT
2. DDT Used to Fight Malaria WHO: World Health Organization claims that DDT has saved 50,000,000 lives
In the beginning DDT was a miracle chemical that destroyed mosquitoes and controlled Malaria
3. DDT Benefits and Production Between 1945-1960 DDT was used to control agricultural pests and disease carrying insects.
Chemical companies discovered more insecticides: Chlordane, dieldrin, mirex, methoxychlor, and lindane. DDT sprayed to control: Gypsy Moth, Dutch Elm Disease, Fire Ants, and mosquitoes.
Chemical companies increase production: 53’-38million, 57’- 84 million and by 60’- 125 million pounds
4. Rachel Carson’s Silent Spring
5. Silent Spring Fall-out
6. A Giant Awakes!
7. Chemical Companies Response
8. Peregrine falcon populations declining since 50’s
Occupy same nest each year
Raptor top of food chain
Could chlorinated insecticides be responsible?
9. Madison Conference Conclusions
10. Environmental Defense Fund Legal battle against DDT
11. DDT Facts Banned in many developed countries, it is still used today to fight yellow fever, sleeping sickness, typhoid & malaria.
Persistent in Temperate climates (years) compared to Tropical climates (months).
DDT is insoluble in water but accumulates in soil which acts as a sink.
DDT accumulates in the body fat of animals. High trophic level feeders contain higher concentrations.
12. DDT Facts Continued LD50 levels are 150-400 mg/kg of body weight, relatively low.
Long term exposure leads to liver damage, tremors and hyperactivity.
DDT levels of 200mg/kg in rats show no sign of poisoning, multiply by 70 to relate to human values.
DDT has no teratogentic properties but can develop tumors in rats at concentrations near 500mg/kg.
13. DDT Facts continued Humans do not appear to be affected by DDT studies of humans over a 25 year period in which they were given 0.25mg.kg showed no adverse effect.
Because DDT accumulate in body fat DDT exposure should be avoided to prevent tumor development