1. Environmental Problems 7 th Grade Science Pg. 78

2. Pollution -unwanted change in environment. -what causes it? -wastes, forms of energy -pollutant – anything that causes pollution. -some made by natural events (volcanoes). -some made by humans.

3. Garbage – Cause of Pollution -average American – 12kg of trash per week. -goes to landfills. -hazardous waste – can catch fire, corrode (eat through metal), explode, make people sick.

4. Chemicals – Cause of Pollution -may help people, but may harm environment. -2 groups of harmful chemicals: 1. CFC’s (chlorofluorocarbons) – destroy ozone. Used in aerosols, refrigerators, plastics. 2. PCB’s (polychlorinated biphenyls) – poisonous & may cause cancer. Used in appliances & paint. -now banned, but still remain in atmosphere.

5. Radioactive Waste – Cause of Pollution -hazardous waste that gives off radiation. -produced by nuclear power plants. -may take 1000’s of years to recover. -Chernobyl disaster, Ukraine. 1986.

6. Noise – Cause of Pollution

7. Resources -Renewable – can be used over & over. -nearly unlimited supply. -solar, wind, geothermal energies. -Nonrenewable – cannot be replaced, or takes thousands or millions of years to. -fossil fuels – coal, oil.

8. Exotic or Invasive Species -Organism that makes a home in a new place outside native area. -free from predators. -become pests. -can take over new area. ex: zebra mussels in Lake Erie Lake Erie

9. Overpopulation -Too many individuals for the available resources. -Figure 5, pg. 81 -1800- 1 billion people on Earth. -2000- over 6 billion. -Why are people living longer? -advances in medicine, farming, others? -Impacts on Earth?

11. Point-Source Pollution vs. Nonpoint-source Pollution -Point-source: pollution that comes from one source. -ex: oil spills -Nonpoint-source: comes from many different sources. -ex: runoff chemicals into lake or river

12. Solutions -REDUCE, REUSE, RECYCLE!!!!! -figure 11, pg. 90. -can you think of any others?