1. What environmental factors are related to the spread of disease?

2. Conditions Favorable to Infectious Diseases  Overcrowding  Lack of Sanitation  Climate (Warm and Wet)  Contaminated Water Supply

3. Environmental Factors Related to Non-Infectious Disease  Long term exposure to certain chemicals  Carcinogen: a substance in the environment that may cause cancer.

4. 3 Common Factors  Ultraviolet Light (UV): can result in skin cancer. Ozone in our atmosphere absorbs UV light.  Vinyl Chloride: used to make PVC plastic. Exposure through breathing vapors. Leads to liver, brain, and lung cancer. Still on the market b/c its so useful.  Arsenic: occurs naturally in soil and rock. Widely used in pesticides and as a wood preservative. No longer used b/c of its links to liver, bladder, kidney, and lung cancer. Also poisonous and lethal if consumed in large doses.