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The DDT Story
DDT, a powerful insecticide, is invented by chemist Paul Hermann Muller
Typhus outbreaks cause threats in Allied troops during WWII. DDT is used to kill insects that transmit deadly diseases to people
Muller is awarded the 1948 Nobel Prize in Physiology or Medicine for his discovery
DDT is widely used on crops to control damage from insects
Toxic effects of DDT were first recorded
Rachel Carson publishes her book, Silent Spring, describing how pesticides spread through the environment
DDT is severely restricted in Canada
About 10 years after DDT was first used, dead birds, fish, frogs, and other animals were found in areas where DDT had been sprayed
Tests of soil and water showed that DDT remained in the environment for many years
DDT was also being found in bodies of organisms in areas around the world where DDT had not been sprayed.
DDT shows up in tissues of people
Numbers of hawks, eagles and ospreys across Europe and North America fall drastically due to biomagnification
Malaria incidents increase 50-60%
What actually happens with DDT?
It accumulates in the body of an organism. When a larger organism from a higher trophic level eats this organism, there is a higher concentration of DDT present.
This is BIOMAGNIFICATION
Advantages/Disadvantages of DDT
ADVANTAGES DISADVANTAGESGets rid of typhus Toxic effects
Used on crops to control damage from insect
pests
Kills organisms
Gets rid of malaria Builds up in tissue and affects organisms at higher tropic levels
Affects reproduction of birds of prey