Pesticides

Pesticides are… Poisons that are sprayed to kill insects and other pests. Examples include DDT, DEET, “Roundup”, and diazinon.

Dosage Types Lethal Dose – The amount it takes to kill an organism. Non-Lethal Dose – An amount that isn’t enough to kill, but might be enough to keep an animal from being able to reproduce.

Bioaccumulation is… When an animal ends up with a lethal dose of pesticide because it ate many smaller animals that had eaten non-lethal doses of pesticide. The pesticides build up in its system.

What is being done about this? People first paid attention when Rachel Carson wrote “Silent Spring” in Laws were passed banning some of the most harmful pesticides. Many are still used elsewhere in the world.

Banned Pesticides Mercury compounds Dieldrin DDT

Mercury… Builds up in the bodies of living things, and causes brain, heart, kidneys, lungs, and immune systems. Pregnant women are told not to eat fatty fish like tuna because of bioaccumulation and the risk of mercury poisoning for the growing baby.

DDT… Also builds up in fat tissue. Causes heart problems, reproductive problems, and death. Even though it was banned in 1972, most Americans have some DDT in their body. Responsible for the bald eagle becoming endangered.

Although we have taken steps to ban the most harmful pesticides, they are still one of the reasons many animals are endangered.