Harmful Effects of DDT on the Earth

By: Ligaya Madamba

DDT

During World War II, Paul Hermann Müller discovered that the chemical, DDT, could be used as an insecticide.

What is DDT?

A hydrophobic (repelled by water), odorless, colorless, crystalline solid that is not very soluble in water. It is created by reacting trichloroethanal and chlorobenzene.

DDT as an Insecticide

Often referred to as the “atomic bomb” of pesticides, DDT, was used to kill malaria carrying mosquitoes and many more

insects that carried typhus and other diseases. It was also used to kill various arthropods that attacked farms.

Effects of DDT

BENEFITSFrom 1948 to the 70s, DDT seemed to be very

beneficial. DDT:-completely destroyed malaria from Europe,

Brazil, Egypt, and North America-controlled typhus carried by lice in Italy-controlled insects that carried yellow fever

DDT during the Early 70s

In a matter of ten years people started doubting DDT. Personal observations were made about the decline in bird sightings.

In 1962, Rachel Carson wrote a novel, Silent Springs, which exposed the effects of DDT. Nothing was done until the early 70s.

More Sightings of Harmful Effects

-In 1965 there was a massive decline in fish at Yaphank Ponds after a spraying of DDT.

-Decrease in large birds like ospreys and eagles (this was due to DDT’s thinning effect on their egg shells)

In 1972 DDT was finally banned by the US Environmental Protection Agency (EPA).

Why is DDT So Harmful?

DDT is a big concern because it is very insoluble in water, but fairly soluble in fats. It’s structure makes it very difficult for it to breakdown in nature.

Since DDT is hard to breakdown and is very insoluble in water it can stay in the environment and even in human bodies for decades.

What Does DDT Affect?

EVERYTHING!DDT in microorganisms (i.e. green algae) grow

slower and carry out photosynthesis slower. Since these organisms are at the bottom of the food chain the DDT found in higher organisms is magnified. Invertebrates found on land are not deeply affected, but aquatic invertebrates are. Fish and birds are extremely sensitive to DDT.

DDT in Humans

DDT in large amounts can cause headache, confusion, tremors, and nausea. It may even be linked to breast cancer because DDT mimics estrogen. There are also hypotheses that it decreases the sperm count in men.

DDT DDT NowNow

DDT is completely banned from the US. It is still used in countries like China, South America, Africa, and Malaysia.

In most areas DDT has become completely unsuccessful…mosquitoes in India and other areas are now immune to DDT.