Copy of Copy of APES Unit 8 Notes

Unit 8: Aquatic & Terrestrial Pollution

8.1 Sources of Pollutants

• Understanding different types of pollutant sources:

  • Point Source: Pollution that comes from a single, easily identifiable source (e.g., smokestacks, wastewater treatment plants).

  • Nonpoint Source: Pollution that comes from multiple sources, making it hard to pinpoint a specific origin (e.g., urban runoff, agricultural runoff).

Point vs. Nonpoint Pollutant Sources

• Examples of Point Source Pollution:

  • Emissions from coal power plants (CO2, NOx, SO2, PM)

  • Waste from concentrated animal feeding operations (CAFOs) (e.g., ammonia, fecal coliform)

  • Accidental spills (e.g., 2010 BP oil spill)

• Examples of Nonpoint Source Pollution:

  • Urban runoff containing oils, fertilizers, and sediments

  • Pesticide usage in agriculture leading to runoff

Pollution Terminology

• Pollutants: Specific chemicals that enter the environment and can have harmful effects on health and ecosystems.

• Pollution: The broad term describing the introduction of pollutants into the environment.

• Key focus should be on specific pollutants:

  • Their sources

  • Environmental & human health effects

  • Mitigation strategies

8.2 Human Impacts on Ecosystems

• Organisms' range of tolerance for abiotic factors (pH, temperature, nutrients) impacts their survival.

  • Pollutants can induce physiological stress, leading to:

    • Reduced growth and reproductive output

    • Increased difficulty in respiration

    • Hormonal disruptions and potential mortality

• Emphasis on explaining specific pollutant effects is crucial for understanding ecological impacts.

Environmental Effects of Acid Rain

• Lower pH levels disrupt ecosystems, primarily causing:

  • Aluminum toxicity and osmotic balance issues.

• Indicator species can signal changes in ecosystem health based on pH levels.

Temperature Tolerance of Reef Algae

• Coral reefs are reliant on zooxanthellae for nutrients; temperature spikes can lead to bleaching and reef degradation.

• Pollutants from agricultural runoff can further exacerbate stress on algae and coral systems.

Human Impacts on Coral Reefs

• Major threats include:

  • Increased water temperatures due to greenhouse gas emissions.

  • Urban and agricultural runoff introducing toxins, nutrients, and sediments.

  • Overfishing and destructive practices like bottom trawling.

Oil Spills and Their Effects

• Hydrocarbons can severely impact marine life through:

  • Direct ingestion and absorption.

  • Physical effects including reduced visibility and oil coating birds.

  • Long-term habitat degradation in estuaries due to oil settling in root structures.

Oil Spill Clean-up Methods

• Physical containment and removal techniques:

  • Booms and skimmers.

  • Chemical dispersants and their possible harmful effects on ecosystems.

  • Burning off oil and the implications of such practices.

8.3 Endocrine Disruptors & Industrial Water Pollutants

• Endocrine Disruptors (EDCs): Chemicals that interfere with hormonal systems through receptor binding and mimicking hormones.

  • Example: Atrazine affecting male frogs' reproductive systems.

Common EDCs and Their Sources

• Atrazine, DDT, and Phthalates are significant compounds with widespread environmental and health implications due to improper disposal, agricultural runoff, and chemical manufacturing effects.

8.4 Human Impacts on Wetlands and Mangroves

• Wetlands: Vital ecosystems providing numerous services including flood regulation, nutrient cycling, and wildlife habitat.

• Major threats to wetlands include pollutants, water diversion, and development.

8.5 Eutrophication

• Key Process:

  • Excess nutrients (N & P) lead to algal blooms, block sunlight, and cause hypoxia (low O2 levels).

  • Feedback loops exacerbate oxygen depletion as decomposing algae use up oxygen.

8.6 Thermal Pollution

• Thermal pollution decreases oxygen solubility in water, affecting organism respiration due to increased temperatures.

• Common sources include power plants and urban runoff.

8.7 Persistent Organic Pollutants (POPs)

• Characteristics of POPs:

  • Long-lasting, bioaccumulate in organisms, and impact endocrine functions leading to reproductive health issues.

• Examples: DDT, PCBs, and dioxins from various industrial processes.

8.8 Biomagnification

• A process by which pollutants accumulate in organisms up the food chain.

• Methylmercury and POPs can reach dangerous levels in top predators, causing bioaccumulative effects on wildlife and humans.

8.9 Solid Waste Disposal

• MSW (Municipal Solid Waste): Contains everyday products from urban areas including hazardous e-waste.

8.10 Waste Reduction Strategies

• Utilize the three R's: Reduce, Reuse, Recycle to minimize waste impact on environments.

Sewage Treatment Process

• Importance of treating wastewater to remove contaminants and prevent pollution of surface waters.

• Main steps include:

  1. Primary treatment: removing large solids.

  2. Secondary treatment: biological breakdown of organic matter.

  3. Tertiary treatment: removing further nutrients to prevent eutrophication.

Health Impacts of Pollutants

• Understanding routes of exposure and synergistic effects.

  • Pathogens and infectious diseases spread via contaminated water or vectors like insects.

  • Specific diseases like dysentery, malaria, and tuberculosis highlight the public health implications of environmental pollution.