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