2. How can chemicals both cause and cure disease?

3. Exposure The actual contact that a person has with a chemical. If the exposure is repeated over a long period of time it is CHRONIC exposure.

4. Types of Exposure Inhalation: breathing in of a substance in the form of gas, vapor, fumes, or dust. Ingestion:process of taking in a substance into the body through the mouth. Absorption:penetration through the skin.

5. Dose, Concentration, and Potency Dose: amount of chemical absorbed into and processed by the body during an exposure. Concentration: amount of material (chemical) in a larger amount of another material. (blood stream) Dose-Response Relationship: body’s response to differing amounts of a chemical. Threshold: dose below which a chemical causes no adverse effects to the human body. Potency: measure of its strength and ability to produce a given effect.

6. Individual Susceptibility An individual is considered susceptible to a specific chemical if they experience a severe reaction when exposed to it. Susceptibility is influenced by age, gender, genetics, health status, and lifestyle.

7. Risks and Benefits of Chemicals Benefit: advantage or outcome that promotes well-being. Risk: possibility of suffering harm or loss. Examples: Medicine, Preservatives, Sanitation, Crop Yield

8. Medicines Benefit: ease our discomfort when we are not feeling well. Risks: Side effects- when treatment affects organs or tissues other than the ones being treated. Might not work as intended.

9. Preservatives Benefits: prevent food spoilage. Maintain product consistency Improve nutritional value of food Enhance flavor of food Risks: Can be carcinogenic Can cause severe allergic reactions in some people

10. Sanitation Benefits: Maintain clean, hygienic conditions, that help prevent disease through services such as sewage treatment, garbage collections, and wastewater disposal. Risks: Chemicals that are used are hazardous to store and handle.

11. Crop Yield Chemicals such as fertilizers, pesticides, and herbicides have resulted in plentiful and inexpensive grains, fruits, and vegetables. Pesticides: kills pests (insects) Herbicides: kill weeds Fertilizers: balance soil nutritional levels. N P K Pesticides have been linked to increased prostrate cancer rates among farmers. Contain organophosphates which are known neurotoxins.