2.  PPM –  PPB –  PPT – Parts per million (1 in per 1,000,000, 10 -6 ) Parts per billion (1 part in 1,000,000,000, 10 -9 ) Parts per trillion (1 in 1,000,000,000,000, 10 -12 )

3. 1m

4. 1 cube would be considered 1 PPM

5.  1 inch in 16 miles  1 minute in two years  1 cent in $10,000  1 ounce of salt in 31 tons of potato chips  1 bad apple in 2,000 barrels of apples

6.  1 inch in 16,000 miles  1 second in 32 years  1 cent in $10,000,000  1 pinch of salt in 10 tons of potato chips  1 lob in 1,200,000 tennis matches  1 bad apple in 2,000,000 barrels of apples

7.  1 postage stamp in the area of the city of Dallas  1 inch in 16 million miles (more than 600 times around the earth)  1 second in 320 centuries  1 flea on 360 million elephants  1 grain of sugar in an Olympic sized pool  1 bad apple in 2 billion barrels

8.  Pollution refers to the occurrence of unwanted change in the environment  introduction of harmful or toxic materials into the surroundings  Contamination  similar to that of pollution  implies making something unfit for a particular use through the introduction of toxic materials

9.  Physical hazards = occur naturally in our environment  Earthquakes, volcanoes, fires, floods, droughts  We can’t prevent them, but we can prepare for them  We increase our vulnerability by deforesting slopes (landslides), channelizing rivers (flooding), etc.  We can reduce risk by better environmental choices  Chemical = synthetic chemicals such as pesticides, disinfectants, pharmaceuticals  Harmful natural chemicals also exist  Biological = result from ecological interactions  Viruses, bacteria, and other pathogens  Infectious (communicable, or transmissible) disease = other species parasitize humans, fulfilling their ecological roles  We can’t avoid risk, but we can reduce the likelihood of infection  Cultural = result from the place we live, our socioeconomic status, our occupation, our behavioral choices  Smoking, drug use, diet and nutrition, crime, mode of transportation Environmental health = assesses environmental factors that influence human health and quality of life (Natural and human-caused )

10.  Despite our technology, disease kills most of us  Disease has a genetic and environmental basis  Cancer, heart disease, respiratory disorders  Poverty and poor hygiene can foster illnesses

11.  Tuberculosis, acquired immunodeficiency syndrome (AIDS), and the West Nile virus  Our mobility spreads diseases  Diseases are evolving resistance to antibiotics  Climate change will expand the range of diseases  To predict and prevent diseases, experts deal with complicated interrelationships

12.  Infectious disease  Spread by interactions between individuals and through food, water, air or soil.  Can travel globally via airplanes  New diseases emerging and previous ones reemerging  Some infectious diseases can be controlled by manipulating the environment

14.  If you really knew me…