Unit 8 Study Notes

Important Dates

• Test Date: The unit test will be administered on the 23rd of this month.

• Retake Opportunities: For the lowest summative assignments, retakes will be available the following week during seniors' last week.

Slideshow Access

• The slideshow will be available on Canvas, where all slides have been unskipped to review previously missed topics.

Unit 8 Overview

8.1: Point vs. Nonpoint Source Pollution

• Point Source Pollution:

  • Defined as pollution from a single, identifiable source.

  • Examples include:

  • A factory

  • A car

  • An agricultural field

  • Typically referred to with definite articles, e.g., "a…"

• Nonpoint Source Pollution:

  • Diffuse pollution that does not originate from a single source.

  • Examples include:

  • Agricultural runoff

  • Factory emissions

  • Morning traffic

  • Generally described in more broad terms, e.g., fertilizer use.

Range of Tolerance

• Definition: The range in which organisms can survive and thrive is critical. Each species has:

  • An Optimal Range: Conditions under which they function best.

  • A Range of Tolerance: Beyond which they cannot survive.

• Example: Humans can tolerate temperatures between 104^ ext{F} and 122^ ext{F}.

• Importance in the context of climate change, such as heat-related health issues.

Impact of Acid Rain

• Reduces water pH and adversely affects aquatic ecosystems, stressing organisms beyond their tolerance range.

Endocrine Disruptors

• Chemicals that interfere with the endocrine system (hormones and growth).

• Key metals as endocrine disruptors:

  • Lead: Found in old paints, pipes.

  • Mercury: Emitted from coal plants; bioaccumulates and biomagnifies through food chains.

  • Arsenic: Naturally occurring but released through mining and industrial activities.

Bioaccumulation and Biomagnification

• Bioaccumulation: The accumulation of substances, such as pesticides or other chemicals, in an organism.

• Biomagnification: The increase in concentration of substances in organisms at each trophic level of a food chain.

• Persistent organic pollutants (POPs): Fat-soluble and hard to excrete, accumulating in organisms and ecosystems.

Mangroves and Wetlands (8.4)

• Benefits provided by mangroves include:

  • Water Filtration: They filter pollutants from waters.

  • Coastal Protection: Up to five times more cost-effective against floods than human-made barriers.

  • Habitat for fish species and carbon sequestration.

• Threats include:

  • Coastal development

  • Pollution

  • Aquaculture practices

Eutrophication

• Causes rapid algae growth due to excess nitrates and phosphates, often from fertilizers.

• Cultural Eutrophication: Human-induced algal blooms.

• Related terms:

  • Hypoxia: Low oxygen conditions, detrimental to aquatic life.

Thermal Pollution

• Result of elevated water temperatures, primarily from power plants' cooling processes that decrease dissolved oxygen levels.

Waste Disposal

Landfills

• Majority of landfill contents (about a third) is paper, which is recyclable.

• Hazardous waste: E-waste, yard chemicals, and motor oil must be disposed of differently to avoid contamination.

• Landfill Components:

  • Liner: Prevents leachate and toxins from contaminating soil.

  • Leachate Collection: Manages liquid waste.

  • Methane Recovery: Captures methane gas for energy.

  • Clay Cap: Seals landfills after usage to prevent leakage and animal intrusion.

Waste Reduction Hierarchy

1. Reducing: Most sustainable approach, minimizing consumption of resources.

2. Reusing: Second in sustainability, as it repurposes items without significant resource usage.

3. Recycling: Least sustainable due to energy and water use, as it requires processing raw materials.

Composting

• Effective at reducing landfill waste by breaking down food scraps into nutrient-rich soil, while also lowering methane production from landfills.

Sewage Treatment

• Multiple treatment levels for managing sewage include primary, secondary, and tertiary processes, aimed at reducing harmful pollutants.

LD50 (Lethal Dose 50)

• Definition: The amount of a substance required to kill 50% of a test population, commonly used in toxicity studies.

• Understanding how to read graphs related to LD50 to determine toxicity levels is important for your exam.

Diseases Related to Pollution

• Commonly discussed diseases:

  • Dysentery: Caused by fecal contamination in water; treatable with antibiotics, but problematic in developing countries.

  • Mesothelioma: A lung tumor caused by asbestos exposure.

• Infectious Disease Concepts:

  • Pathogen: Agent causing infectious diseases, typically bacteria or protists.

  • Vector: Organism that transmits the pathogen (e.g., mosquitoes, rats).

• Notable diseases associated with vectors include Malaria and its relation to sickle cell anemia.

Summary of Climate Impact on Diseases

• Climate warming extends the ranges and active periods of disease vectors, impacting public health, especially in developing nations lacking appropriate sanitation and healthcare.

Commonly Referenced Diseases in Coursework

• Tuberculosis: Major health concern in developing countries due to public health deficiencies.

• Malaria and Cholera: Significantly influenced by environmental factors like clean water access and vector presence.

Conclusion

• The quiz will include questions based on previous topics discussed and will focus on understanding concepts rather than purely memorization of facts. Review all key points thoroughly to prepare for the upcoming evaluation!

Miscellaneous

• Consider completing the AP progress check to enhance readiness for the quiz.