Environmental Health and Toxicity- Reverse Lesson 1

Presented by Mrs. Perryman

Antibiotic and Pesticide Wheel

What does this concept mean for you?

• CBS News Report on Antibiotics

Toxic Chemicals

Hazardous• Means dangerous

Toxins• Are poisonous

We will not discuss these formally but be familiar with:

• Allergens• Antigens• Neurotoxins• Mutagens• Teratogens• Fetal Alcohol Syndrome• Carcinogens

• These may appear on the AP exam. I might include them in test questions (as part of the question), so be familiar with their meaning.

Movement, distribution and fate of toxins

Bioaccumulation

• Natural process of an organism selectively absorbing and storing a great variety of molecules

• Organism could not survive with out this process

• Biomass

Biomagnification

• A chemical is stored in tissue and is transferred up the food chain

• Usually your oil/fat soluble toxins

Two visuals to help us with this!

http://www.youtube.com/watch?v=E5P-UoKLxlA

• How does Pacman explain Bioaccumulation and Biomagnification?

Persistence

• Chemical remains for a very long time

• Directly related to the structure of the molecule.

• C-Cl combinations- not found in nature so no microbes have evolved to break them down so they remain in an ecosystem

• Example:Chloroflurocarbons

Chemical Interactions

• Antagonistic reactions- interfere with the intended effects OR stimulate the break down of a needed molecule.

• Example: Vitamin A, D and E can reduce the response an organism has to carcinogens

• Additive- occur together in an exposure

Synergistic Effect

• Interactions in which one substance exacerbates the effect of another

• Example: • London's Killer Fog• Killer Fog Part 2,3, 4,5 and

6 available on Youtube. They are interesting we will discuss this in more detail Second Semester.