AP Environmental Science Unit 8 - Land & Water Pollution

What you need to know for APES Unit 8

Pollution created by human activities directly impacts ecosystems in the air, on land, and in water. 

• Increasing ocean temperatures, ocean acidification and sediment runoff from agriculture practices have caused coral reefs to decline.
• Large scale oil spills kill plants and animals due to chemical and physical impacts.
• Excess nutrients in the ocean from agricultural runoff causes oceanic dead zones.
• Eutrophication is caused by excessive nutrients from agricultural practices causing an increase in plant life in an aquatic ecosystem. 
• Thermal pollution from factories using natural waterways to cool equipment, alters the concentration of dissolved oxygen and tests organism's physical tolerances. 

The source of pollution can sometimes be easy to identify, but other times the source is diffused. 

• Point source refers to a single, identifiable source of a pollutant while nonpoint sources of pollution are diffused and can be difficult to identify

There are many human health issues that can be linked to pollution. 

• Heavy metals impacting the drinking water supply.
• Endocrine disruptors can lead to birth defects.
• Bioaccumulation of toxins in food sources such as large fish can cause issues with the reproductive, nervous, and circulatory systems.
• Dysentery is caused by untreated sewage in streams and rivers.

Practices have been put in place to reduce discharges of pollution in water and regulate drinking water. 

• Modern landfills put in place efforts to make sure toxins do not drain into watersheds. 
• Sewage treatment processes remove organic matter, chemicals and bacteria. Modern sewage plants do not allow collect rain water and do not overflow raw sewage into waterways.  

Increases in waste causes global concerns for organisms that live on land and in water.

• Persistent organic pollutants (POPs) do not easily break down in the environment because they are synthetic.
• Animals and humans are at risk of concentrated toxins in food due to bioaccumulation of these toxins in the cells of living organism increasing up trophic levels. 
• The majority of solid waste is not reclaimed or recycled and is disposed of in landfills. Some countries do not have the means to create modern landfills and dispose of their waste by dumping it in the ocean.

Unit 8 Vocab

• Bioaccumulation
• Biomagnification
• Dose response curve
• Electronic waste
• Endocrine disruptors
• Eutrophication
• Human health issues from pollution
• Human pathogens
• Impacts on aquatic ecosystems
• Landfill structure
• Lethal dose 50% (LD50)
• Nonpoint source pollutant
• Oceanic dead zones
• Oil spills
• Persistent organic pollutants (POPs)
• Point source pollutant
• Recycling processes
• Sewage treatment
• Solid waste
• Thermal pollution
• Wetlands