Unit 8: Aquatic & Terrestrial Pollution Notes

Unit 8: Aquatic & Terrestrial Pollution Notes

8.1 Sources of Pollutants

  • Pollution Sources:
    • Point Source - A single, identifiable source of pollution (e.g., smokestack, waste discharge pipe).
    • Nonpoint Source - Diffused sources that are harder to identify (e.g., pesticide spraying, urban runoff).
Point vs. Nonpoint Pollution Examples

  • Point Source Examples:

    • Emissions from coal power plant smokestacks (releasing CO2, NOx, SO2, PM).
    • BP oil spill (hydrocarbons, benzene).

  • Nonpoint Source Examples:

    • Urban runoff (motor oil, fertilizers, road salt).
    • Pesticides from agricultural fields affecting water bodies.

  • Key Concept: To gain credit in FRQs, always describe specific pollutants, their sources, environmental/human effects, and mitigation strategies.

8.2 Human Impacts on Ecosystems

  • Learning Objective: Describe the impacts of human activities on aquatic ecosystems.
Essential Knowledge

  • Organisms have a range of tolerance to various pollutants, which may lead to:

    • Physiological stress, limited growth/reproduction.
    • Damage due to oil spills (death from hydrocarbons).

  • Coral reefs suffer due to:

    • Thermal pollution (increasing temperatures).
    • Sediment runoff.
    • Destructive fishing practices.

  • Impact Examples:

    • Oil spills damage marine life and harm industries (fishing, tourism).

8.3 Endocrine Disruptors & Industrial Water Pollutants

  • Definition: Endocrine disruptors are chemicals that interfere with hormonal systems in animals.
  • Effects: Can lead to developmental disorders, gender imbalances, and birth defects.
  • Sources: Heavy metals, pesticides (e.g., atrazine, DDT, phthalates).

8.4 Human Impacts on Wetlands and Mangroves

  • Learning Objective: Describe the impacts of human activity on wetlands and mangroves.
  • Ecological Services of Wetlands:
    • Water purification, flood protection, habitat for wildlife.
  • Threats:
    • Pollution from agriculture, urban development, and overfishing.
  • Restoration Efforts: Riparian buffers, enhanced nutrient removal, proper waste management.

8.5 Eutrophication

  • Definition: Eutrophication is when excess nutrients enrich a body of water, leading to algal blooms.
  • Consequences:
    • Algae block sunlight, leading to plant death, hypoxia, and dead zones.
  • Major Nutrient Sources:
    • Sewage treatment plant discharge, animal waste, and synthetic fertilizers.

8.6 Thermal Pollution

  • Definition: Thermal pollution occurs when excessive heat is released into water bodies, harming ecosystems.
  • Effects: Warms water decreases dissolved oxygen, leading to respiratory stress and potential fish kills.
  • Sources: Power plants, industrial discharge, and urban runoff.

8.7 Persistent Organic Pollutants (POPs)

  • Definition: Synthetic compounds that persist in the environment and accumulate in the food chain (e.g., DDT, PCBs).
  • Transport: Can travel long distances via air and waterways.
  • Health Impacts: Concerns regarding their toxicity and impact on human health and ecosystems.

8.8 Biomagnification

  • Definition: Increase of substance concentrations at higher trophic levels in a food chain.
  • Effects on Ecosystems: Eggs with thinner shells in predators due to DDT, neurotoxic effects from methylmercury in fish.

8.9 Solid Waste Disposal

  • Types of Solid Waste:

    • Municipal Solid Waste (MSW): Trash from households/businesses.
    • E-Waste: Discarded electronics that may leach hazardous materials if not disposed of properly.

  • Landfills: Highlights of sanitary landfills include leachate collection systems to prevent contamination and methane recovery systems to capture emissions for energy generation.

8.10 Waste Reduction

  • Three Rs: Reduce, Reuse, Recycle, listed from most to least sustainable.
  • Composting: Method for organic waste decomposition, producing nutrient-rich soil amendment.

8.11 Sewage Treatment

  • Treatment Stages:
    • Primary: Physical removal of large solids.
    • Secondary: Biological breakdown of organic waste.
    • Tertiary: Advanced treatment to remove remaining contaminants.

8.14 Pollution and Human Health

  • Health Issues Related to Pollution:
    • Dysentery: Caused by untreated sewage; leads to severe dehydration.
    • Mesothelioma: Cancer from asbestos exposure.
    • Tropospheric Ozone: Leads to respiratory issues and limited lung function.

8.15 Pathogens and Infectious Diseases

  • Pathogens: Bacterial and viral infections like Tuberculosis, Malaria, and Cholera that spread through contaminated water or vectors like mosquitoes.
  • Human Vulnerability: Increased risk in poor or developing countries with inadequate sanitation and healthcare.