How can chemicals both cause and cure disease?

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.

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.

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.

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.

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

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.

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

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.

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.