10.3.1 Pollution- Land & Water

• What is pollution?


  Pollution is any effect of human activities upon the environment.
• What is a pollutant?


  A pollutant is any product of human activities that has a harmful effect on the environment.
• Why do plastics pose a problem for ecosystems?

  Plastics take a very long time to decompose and can damage both aquatic and terrestrial ecosystems.
• What are terrestrial ecosystems?

  • Ecosystems on LAND
  • Terrestrial organisms live on land
• What are aquatic ecosystems?

  • Ecosystems in water
  • Aquatic organisms live in water
• What are the effects of non-biodegradable plastics on ecosystems?

  They block water passage, reduce oxygen levels, and affect soil fertility.
• What happens to soils when plastics block drains and pipes?

  • Soils become waterlogged
  • Oxygen levels are reduced
  • Soil fertility is affected (denitrification occurs)
• What occurs in landfill sites due to plastic waste?

  Oxygen flow is restricted, leading to anaerobic conditions and denitrification.
• How do animals interact with plastic waste?

  Animals confuse plastic for food, which can block their digestive systems and cause death.
• What is a consequence of burning plastics?

  Burning plastics releases toxic particles into the atmosphere.
• What are pesticides used for?

  Pesticides are sprayed on crops to kill pests that might eat and destroy them.
• What are herbicides used for?

  Herbicides are sprayed on crops to kill weeds that compete for nutrients.
• What is the problem with the overuse of pesticides and herbicides?

  Overuse can cause runoff into water sources, spreading chemicals to other ecosystems.
• How do pesticide levels change in the food chain?

  Pesticide levels increase through the food chain and become more concentrated in higher trophic levels.
• What are the potential effects of pesticides on organisms?

  Pesticides can be toxic, potentially killing organisms or affecting their metabolism.
• What are some solutions to reduce pesticide use?

  • Use degradable pesticides
  • Don’t apply too much
  • Consider genetically modified crops that resist insect attack
• What are fertilizers used for?

  Fertilizers are added to crops to help them grow and increase yield.
• What can happen if excess fertilizers enter water sources?


  It can cause eutrophication.
• What is eutrophication?


  1. Excess nutrients enter water bodies.
  2. Algae grow quickly due to extra nitrates.
  3. Algae block out light.
  4. Bottom plants die due to lack of light.
  5. Decomposing plants provide more nutrients.
  6. Bacteria population increases, using up oxygen.
  7. Reduced dissolved oxygen leads to death of aquatic creatures.
  8. Decomposing bodies provide more nutrients (positive feedback).

  
• How does untreated sewage contribute to eutrophication?

  Untreated sewage contains organic matter that helps algae grow.
• What are the two purposes of treating raw sewage?

  1. Destroy harmful pathogens using high temperatures, chlorine, or UV light.
  2. Remove organic compounds to prevent BOD and eutrophication.
• How can we prevent eutrophication?

  1. Treat sewage
  2. Use the correct quantity of fertilizers
  3. Ensure fertilizers are not applied just before heavy rainfall