2.  Any visible or invisible particle or gas found in the air that is not part of the original, normal composition  Natural: forest fires, pollen, dust storm  Unnatural: coal, wood and other fuels used in cars, homes, and factories for energy

3.  Smog: Fog grabs smoke from coal factories and traps it on the ground  Global warming from excess CO 2 from the burning of fossil fuels  Acid rain from sulfur dioxide, also from the burning of fossil fuels  Respiratory problems

4.  Agriculture runoff - carrying fertilizers, pesticides/herbicides and other pollutants into water bodies  Accidental leaks and spills  Plastic materials/wastes  Intended/illegal discharges of waste

5.  Death of aquatic (water) animals  Disruption of food-chains  Disease  Destruction of ecosystem

6.  The process in an ecosystem by which higher concentrations of a particular chemical, such as the pesticide DDT, are reached in organisms higher up the food chain.  Occurs through a series of predator-prey relationships

7.  A sound of any kind is called a noise.  Unnecessary noises = noise pollution.  Affects human health and quality of life. Hearing loss, high blood pressure, stress, and sleep loss  Examples: airplanes, construction equipment, city traffic, factories, home appliances, and lawnmowers

8.  Sound intensity is measured in decibels (dB).  Quietest sound that we can hear = 0 dB.  For each increase in decibel intensity, the decibel level is 10 times higher than the previous level.  A sound of 120 dB is at the threshold of pain. Permanent deafness may come as a result of continuous exposure.

10.  Not a direct hazard to human health.  Negatively affects our environment. Diminishing our view of the night sky Energy waste  When light is directed upward into the night sky and lost into space.  Examples: billboards, the lighting of building exteriors, and poor- quality street lights.  2 million barrels of oil per day in U.S.

11.  Solutions to energy waste: Shielding light so it is directed downward. Using time or motion controls Using more efficient bulbs