2.  DDT, a powerful insecticide, is invented by chemist Paul Hermann Muller

3.  Typhus outbreaks cause threats in Allied troops during WWII. DDT is used to kill insects that transmit deadly diseases to people

4.  Muller is awarded the 1948 Nobel Prize in Physiology or Medicine for his discovery

5.  DDT is widely used on crops to control damage from insects

6.  Toxic effects of DDT were first recorded

7.  Rachel Carson publishes her book, Silent Spring, describing how pesticides spread through the environment

8.  DDT is severely restricted in Canada

9.  About 10 years after DDT was first used, dead birds, fish, frogs, and other animals were found in areas where DDT had been sprayed

10.  Tests of soil and water showed that DDT remained in the environment for many years

11.  DDT was also being found in bodies of organisms in areas around the world where DDT had not been sprayed.

12.  DDT shows up in tissues of people

13.  Numbers of hawks, eagles and ospreys across Europe and North America fall drastically due to biomagnification

14.  Malaria incidents increase 50-60%

15.  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

17. ADVANTAGESDISADVANTAGES Gets rid of typhusToxic effects Used on crops to control damage from insect pests Kills organisms Gets rid of malariaBuilds up in tissue and affects organisms at higher tropic levels Affects reproduction of birds of prey