AP Environmental Science - Unit 8 Review: Aquatic and Terrestrial Pollution

Introduction

• Human Impact on Environment
  • Human activities often have negative consequences on the environment.
  • Examples include chemical usage, trash, air pollution.
  • Organisms have a range of tolerance for environmental conditions.
  • Example: Polar bears and temperature tolerance.

Specific Examples of Human Impact

• Coral:
  • Climate change causes coral bleaching and death.
• Oil Spills:
  • Hydrophobic oil spreads rapidly, affects bird feathers, sinks to kill benthic species.
  • Makes fish unsafe to consume.
  • Examples: Deepwater Horizon, Exxon Valdez.
• Plastics:
  • Do not decompose, photo degrade to smaller pieces.
  • Ingested by marine animals, release toxins.
• Endocrine Disruptors:
  • Alter hormones, cause birth defects, developmental/reproductive effects.

Types of Pollution

• Point Source Pollution
  • Directly identifiable sources (e.g., smokestacks, outflow pipes).
• Non-Point Source Pollution
  • Diffuse sources, often runoff-related (e.g., fertilizers from farm fields).

Eutrophication

• Steps Involved:
  • Runoff carries nutrients, increases algae, blocks sunlight, reduces photosynthesis.
  • Algae die and decompose, reducing dissolved oxygen (DO).
  • Leads to fish/plant die-offs, potential dead zones (e.g., Gulf of Mexico).

Oxygen Sag Curve

• Biological Oxygen Demand (BOD):
  • Low BOD indicates oxygen-rich water.
  • High BOD indicates pollution, high oxygen consumption.
• Oxygen Sag Curve:
  • Shows changes in DO and BOD from a pollution source.

Bioaccumulation and Biomagnification

• Mercury:
  • Released from coal burning, forms toxic methylmercury.
  • Bioaccumulates in organisms, biomagnifies in food chains.

Thermal Pollution

• Causes:
  • Release of hot water (e.g., from power plants).
  • Affects species' well-being, reduces oxygen.

Terrestrial Pollution

• Solid Waste Management:
  • Landfills:
    • Use liners, leachate collection, methane capture.
  • Incineration:
    • Reduces volume, releases air pollution.
  • Recycling:
    • Energy-intensive, only certain materials recyclable.

Sewage Treatment

• Levels of Treatment:
  • Primary: Physical removal of large objects.
  • Secondary: Biological treatment with bacteria.
  • Tertiary: Chemical treatment and disinfection.

Human Health and Environmental Science

• Spread of Diseases:
  • Warming temperatures expand disease ranges (e.g., West Nile, Zika).
  • Pathogen spread linked to poverty, lack of sanitation.
• Lethal Dose 50 (LD50):
  • Dose required to kill 50% of a population.

Environmental Laws

• Clean Water Act:
  • Regulates discharges into navigable waters.
• Safe Drinking Water Act:
  • Protects aquifers from contamination.
• RCRA (Resource Conservation and Recovery Act):
  • Monitors hazardous waste from creation to disposal.
• CERCLA (Superfund):
  • Mandates hazardous waste cleanup responsibility.
• Delaney Clause:
  • Bans carcinogenic food additives.

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