Pesticides, diseases, and DDT1) What are two ways chemicals get into the environment?

b) What is the difference between persistent and non-persistent?

2) What is the difference between pesticides, herbicides, and insecticides?

3) What does ingestion and absorption mean?

4) What is one pro and one con for DDT?

Looking at this photo: How are chemicals getting into our water system?

Types of wastesNon- persistent: Will break down by natural ways in the environment. Ex) sewage

Persistent: Will not break down in the environment very easily. Ex) DDT, mercury

Pesticides

Pesticide: Herbicides Insecticides

What they control plants insects

Example pests Weeds Mosquitoes

Example pesticides Roundup DDT

DDT

• Dichlorodiphenyltrichloroethane

… We’ll just call it DDT

DDT

- Used in WWII to exterminate lice.

PRO

DDT: Lice/Typhus- The lice carried the disease typhus, which cause devastating effects, sometimes even death, on the soldiers.

PRO

DDT: Mosquitoes/ malaria- Mosquitoes carry malaria, which causes your red blood cells to burst open. This means they can no longer carry oxygen.

PRO

Pros of DDT:

- In African countries, the use of DDT caused a drop of malaria from 70% to 5% in just 6 years.

PRO

How DDT gets into organisms

Ingestion: eat it. Digestive system

Inhalation: Breath it in. Respiratory system

Absorption: absorbed through the skin. Circulatory system

Evidence against DDT-It has a half-life of 12 years. Meaning it does not leave the environment for many many generations.

- It is fat-soluble meaning it dissolves into fat stores and stays in organisms for decades.

CON

Peregrine Falcon-Stops the flow of calcium from mother to eggs. This meant the eggs were not at thick and strong as they should be.- These brittle eggs would break, resulting in less falcons making it to adulthood.- These birds almost went extinct

CON

DDT: collects in the food chain- As DDT moves up the food chain. More of it collects in the fat stores of animals.

Biomagnification

- Build up of substances, such as pesticides, in an organism.

- It is being absorbed faster than the substance is lost.

DDT debate

• Life-saving or life-threatening?

Pesticides, diseases, and DDT1) What are two ways chemicals get into the environment?

b) What is the difference between persistent and non-persistent?

2) What is the difference between pesticides, herbicides, and insecticides?

3) What does ingestion and absorption mean?

4) What is one pro and one con for DDT?