Unit 8: Aquatic & Terrestrial Pollution Notes

Point Sources:
- Defined as a single, identifiable source of a pollutant, such as:
- Smokestack from power plants emitting CO2, NOx, SO2, PM
- Waste discharge pipes from factories
- Examples:
  - Emissions from a coal power plant
  - The BP Oil Spill releasing hydrocarbons and benzene
Nonpoint Sources:
- Pollution that originates from multiple, diffuse sources, making it difficult to identify a single source. Common examples include:
- Urban runoff containing motor oil, nitrate fertilizer, and sediment
- Agricultural runoff with pesticides and excess fertilizers
Differentiating Point and Nonpoint Sources:
- Point sources can be easily identified (hence the name).
- Nonpoint sources are widespread and often tied to land use practices.

General Effects of Pollutants on Organisms:
- Organisms have a range of tolerance for abiotic factors and pollutants. When these factors change due to human activities, effects include:
- Physiological stress
- Limited growth & reproduction
- Death at high pollutant concentrations
- Specific Examples:
- Damage to coral reefs due to increased temperature and pollution
- Effects of oil spills:
  - Toxic hydrocarbons contaminate water and can directly kill marine life, or disrupt ecosystems and food webs.

Endocrine Disruptors:
- Chemicals that interfere with hormone systems in organisms, leading to negative health outcomes such as birth defects and developmental disorders. Examples include:
- Atrazine (herbicide affecting male frogs)
- DDT and PCBs (last long in the environment, accumulated in tissues)
Heavy Metals:
- Metal pollutants can leach into groundwater and cause health issues. Key metals include:
- Mercury: is converted to methylmercury in aquatic systems, highly toxic to living organisms.
- Arsenic: found in drinking water, poses cancer risks.
- Lead: neurotoxicant impacting brain development.

Wetlands:
- Areas regularly submerged/saturated, providing critical services like water filtration, habitat, and flood protection.
Threats include:
- Commercial development, water diversion, pollutants from agriculture, and overfishing.

Eutrophication Process:
- Excess nutrients (N, P) fuel algal blooms, which eventually die and decompose, leading to hypoxia (low oxygen) and dead zones.
Major Anthropogenic Sources:
- Runoff from agriculture and wastewater release contribute significantly to nutrient pollution.

Definition:
- When excess heat is released into water, affecting dissolved oxygen levels and harming aquatic life.
Sources Include:
- Industrial discharges and urban runoff from asphalt surfaces.

Characteristics:
- Synthetic, fat-soluble chemicals that do not easily decompose. They bioaccumulate in organisms, leading to toxicity through food webs.
Examples:
- DDT, PCBs, phthalates, and dioxins.

Bioaccumulation:
- Refers to the increase of a contaminant in an organism over time, particularly with fat-soluble pollutants.
Biomagnification:
- Describes how contaminants become more concentrated at each trophic level in a food web, leading to high levels in apex predators.

Types of Solid Waste:
- Municipal solid waste (MSW), electronic waste (e-waste), and hazardous waste.
Disposal Methods:
- Landfilling, incineration, and ocean dumping are common methods, each with environmental consequences.

Reduce, Reuse, Recycle:
- Prioritize minimizing consumption, reusing goods, and recycling materials to reduce waste.
Composting:
- Decomposing organic materials can enrich soil and reduce landfill volume.

Sewage Treatment Processes:
- Primary: Physical removal of solids
- Secondary: Biological breakdown using bacteria
- Tertiary: Additional treatment to remove nutrients and pathogens before discharge.

Diverse Exposure Routes:
- Pollutants can enter through water, air, and food.
Health Impacts:
- Examples: Dysentery, tuberculosis, malaria, and others influenced by environmental and sanitary issues that facilitate pathogen spread.