What is biological magnification? Give some examples.
· Toxic substances build up in lower level organisms.  As other organisms eat these organisms, toxins are built up in that organism.   As these substances climb the food chain they grow in concentration.
· Mercury poisoning in Japanese fish
· DDT in eagles and peregrine falcons

What are some other examples of water pollution?
· Heated water from nuclear power plants
· Oil spills like the Exxon Valdez

What are some of the problems with aerosols?
· Aerosols are tiny particles suspended in the air
· They block the sun's rays and lower surface temperature
· SO₂ causes acid rain
· Fossil fuels contribute to acid rain, high amounts of CO₂, and smog.

How is solid waste disposed of?
· Buried in a landfill - takes up space
· Burned in an incinerator for energy - causes some pollution

Many countries have introduced programs to improve the lives of their citizens and to halt the deterioration of the environment.  Some of the programs are aimed at family planning to slow the rate of population growth.  Other programs deal with disease control and sanitation.  There are also programs aimed at pollution control, conservation of natural resources, and preservation of existing species.

What are some countries doing to control pollution?
· Emission controls on automobiles and any fuel burning machinery. (catalytic converters, scrubbers, buffers)
· Ban the use of aerosols especially CFCs
· Sewage treatment plants that break down waste naturally
· Proper dumping of toxic waste materials (landfills, etc..)

What is the difference between renewable and nonrenewable resources?
· Renewable resources may be replaced or replenished by natural events while nonrenewable resources may only be used once.
· Renewable - air, water, soil, sunlight, and living things
· Nonrenewable - coal, oil, natural gas, metals, and minerals.  These maybe recycled however.

Describe how the following is being conserved.
Soil-
· Cover crops are used to prevent soil erosion.  Plants with fibrous roots that hold soil in placed are planted.  One method is strip cropping where strips of cover crops are placed between other crops.
· Terracing flat area are cut into a slope or hill to prevent water from running straight down and carrying soil away
· Contour farming crops are plowed across slopes to prevent erosion.
· Windbreaks help to slow down wind erosion.
· Dams slow down running water and flooding.  Also help with water conservation.
· Crop rotation changing crops to replace nutrients in soil.  Also use fertilizer

Forest-
· Sustained yield tree farming methods such as
Block cutting - only cut blocks of trees
Strip cutting - strips of trees are removed
            Selective harvesting - only certain trees are removed
· Better than clear cutting trees have a chance to replace themselves.
· Reforestation - trees are replants in areas that have been cut.  Takes a long time unless using certain trees.
· Alternatives - Hemp can be used for many of the same products we use trees for with as good as or  better quality.   A lot of red tape!  Composites- part plastic part wood. Use less timber  Can be      expensive.

Wildlife-
· Destruction of habitat, hunting, and pollution has caused a decline in the population of many species.
· Endanger Species Act - animals are now protected from over hunting and destruction of habitat.
· Populations are being restored.
· Wildlife refuges and preserves are being built.
· Restricting the use of pesticides and herbicides

What is being done to control pests?
· Introducing natural predators.  Must be done carefully.
· Crop rotation - some organism like only certain plants so their food is continually moved.
· Pheromones - natural chemicals that attract or repel insects are used to trap them or get rid of them.