Atmospheric and Aquatic Pollution Notes

Atmospheric and Aquatic Pollution Review

Introduction

  • Review of key content and skills from Unit 7 (Atmospheric Pollution) and Unit 8 (Aquatic and Terrestrial Pollution).
  • Focus on solutions for reducing pollution, data analysis, research studies, experimental design, and multiple-choice/free-response question strategies.

Atmospheric Pollution

Sources of Air Pollution
  • Natural Sources: Volcanoes (emit carbon dioxide and SOX compounds).
  • Anthropogenic Sources: Primarily from combustion.
Types of Pollutants
  • Primary Pollutants: Emitted directly from combustion.
  • Secondary Pollutants: Formed after gases react in the atmosphere (cause most environmental and health problems).
  • Classified as gases or solid particulates; interaction with ecosystems and the body depends on their chemical nature.
Photochemical Smog

  • Challenging concept due to complex chemistry.

  • Photochemical: Sunlight-activated, breaking chemical bonds to form new compounds (secondary pollutant).

  • Smog: Term from the early 1900s, describing a "soup" of harmful chemicals.

  • Formation:

    • Reactants: NOx (nitrogen oxides), VOCs (volatile organic compounds).
    • VOC Example: Aldehydes (evaporate quickly).
    • Sunlight breaks chemical bonds.
    • React to form ozone (O3).

  • Visual Representation:

    • NOx (mix of NO and NO2), represented as NOx.
    • VOCs: Hydrocarbons with weak intermolecular forces, easily evaporate.
    • Sunlight: Breaks chemical bonds.
    • Ozone: Main ingredient of photochemical smog.

  • Impacts:

    • Respiratory problems.
    • Eye irritation.
    • Disruption of photosynthesis in plants.
Thermal Inversion

  • Natural phenomenon where cold air mass gets trapped.

  • Normal Situation: Sun warms lower atmosphere, warm air rises and cools.

  • Inversion: Cold air mass (e.g., from the ocean) is trapped by mountains or buildings.

  • Impact: Traps photochemical smog, increasing risk of high air pollution days.

Acid Deposition

  • Secondary pollutant formed when acid gases react with water vapor (acid rain, sleet, or snow).

  • Formation:

    • NOx (from car exhaust) + water vapor → nitric acid (acid rain).
    • SOx (from coal combustion) + water vapor → acid rain.
    • Carbon dioxide (from combustion) + water vapor → carbonic acid (acid rain).

  • pH Scale Reminder: Low numbers are acidic.

  • Acid Rain pH: 4.3.

  • Clean Rain pH: 5.6 (due to natural carbon dioxide).

Indoor Air Pollutants
  • Harmful due to confined spaces, limiting dispersion.
  • Natural Sources:
    • Radon: From uranium decay, radioactive gas seeping into basements (second leading cause of lung cancer).
  • Anthropogenic Sources:
    • Asbestos: Mineral used in insulation, small fibers become airborne and lodge in lungs, leading to cancer.
Example: Analyzing Visual Representations
  • Scenario: Identifying thermal inversion in a diagram.
  • Explanation: Warm and cold air layers indicate inversion; it traps pollutants (ozone, particulates) in the lower atmosphere, exposing humans to higher concentrations and causing respiratory irritation.
Example: Interpreting Data Trends

  • Scenario: Graph showing concentrations of gases in an urban area over time.

  • Observations:

    • NOx concentrations peak in the early morning, then decrease.
    • Ozone concentrations peak in midday.

  • Explanation: Ozone peaks as NOx emissions from cars react with sunlight and hydrocarbons.

Strategies to Reduce Ozone Concentration
  • Promote carpooling (reduces NOx emissions).
  • Financial incentives for replacing gas vehicles with electric vehicles (reduces NOx emissions).
  • Redesign urban areas to encourage walking/biking (reduces car traffic, NOx emissions).
  • Invest in public transportation (reduces car traffic, NOx emissions).

Aquatic and Terrestrial Pollution

Range of Tolerance
  • Organisms have an optimal range of pH, dissolved oxygen, nitrogen, and phosphorus.
  • Outside this range, organisms experience stress, limiting growth, reproduction, and potentially causing death.
Aquatic Pollutants and Impacts
  • Nitrogen and Phosphorus (from fertilizer runoff):
    • Impact: Eutrophication (nutrient enrichment).
  • Sediment (from erosion, construction):
    • Impact: Turbidity (cloudiness) reduces sunlight penetration, heats upper layers.
  • Fecal Coliform (from animal/human waste):
    • Impact: Waterborne diseases (e.g., dysentery).
  • Dissolved Solids (road salt, fertilizers):
    • Impact: Disrupts photosynthetic ability and water transport in organisms.
Visual Representation: Nutrients, Dissolved Oxygen, and Biochemical Oxygen Demand (BOD)

  • X-axis: Distance downstream.

  • Y-axis: Relative concentration of BOD and dissolved oxygen.

  • Point Source Pollution:

    • Spike in BOD (decomposers use oxygen to break down organic matter).
    • Drop in dissolved oxygen (can’t support aquatic life).

  • Non-Point Runoff (Eutrophication):

    • Fertilizer runoff (nitrogen and phosphorus) causes algal bloom.
    • Algae die, decomposers use up oxygen.
    • Lack of dissolved oxygen causes fish die-offs (dead zone/hypoxia).

  • Example: Gulf of Mexico dead zone due to Mississippi River runoff, causing economic impacts (fishing, tourism).

Sewage Treatment

  • Developed world: State-of-the-art sewage treatment plants.

  • Developing world: Still a problem, children susceptible to diseases.

  • Three Basic Steps:

    • Primary Treatment: Physical process (screens, filters) to remove large objects.
    • Secondary Treatment: Biological process (mimics natural decomposition with oxygen and bacteria), bacteria break down organic matter.
    • Tertiary Treatment: Removes excess nitrates and phosphates to prevent eutrophication.
    • Final Step: Water treatment (chlorine, ozone, UV light) to kill pathogenic bacteria (E. Coli, fecal coliform).
Strategies/Solutions for Water Pollution Problems
  • Reducing runoff from farms and lawns.
    • Buffer zones (trees, vegetation) to absorb excess nitrogen and phosphorus.
    • Nutrient management techniques (timing fertilizer application, monitoring soil levels).
    • Control livestock access to waterways/manage manure.
    • Minimizing tillage.
Legislative Solutions
  • Clean Water Act: Regulates discharge of pollutants, funds sewage treatment plants.
  • Safe Drinking Water Act: Sets standards for drinking water.
Waste Disposal and Management
  • Waste Hierarchy: Reduce, Reuse, Recycle (goal: minimize landfill waste).
  • Modern incineration plants (recover energy, air pollution control devices).
Landfill Architecture
  • Lined with clay (low permeability, protects aquifer).
  • Leachate collection system (collects rainwater that permeates through waste).
  • Groundwater monitoring well (to detect leaks into the aquifer).
  • Methane recovery system (captures methane from anaerobic decomposition), can then be used as an energy source.
Problems with Waste Disposal
  • Illegal disposal of tires (breeding grounds for mosquitoes).
  • E-waste (harmful heavy metals). Plastic in oceans (entanglement, ingestion by wildlife).
Persistent Organic Pollutants (POPs)
  • Last a long time (hundreds of years for plastics).
  • Carbon compounds that are water-insoluble/fat-soluble.
  • Example: DDT (sprayed to kill insects).
  • Bioaccumulation: Concentration increases in tissue of an organism.
  • Biomagnification: Concentration increases from one trophic level to another.
Toxicity Measurement
  • Dose Response Curve:
    • X-axis: Dose (mg/kg).
    • Y-axis: Percent mortality.
    • Important data points: LD50, threshold level of toxicity.
    • LD50: Dose that kills 50% of the test population.
Pathogens and Infectious Disease
  • Infectious/vector-borne diseases (transmitted through mosquitoes, ticks, fleas).
  • Vector: Mode of transmitting the pathogen (e.g., mosquito).
  • Understanding the life cycle is important to reducing a vector-borne disease.
    • Can prevent a vector from ever growing into adulthood.
  • Climate change is expanding the habitat range to northern latitudes.

Examples and Practice Questions

Multiple Choice
  • Example: LD50 graph identification.
Free Response Questions (FRQ)

  • Mobile Device Sales Percent Increase Calculation:

    • Calculate the difference between the number of the mobile devices in each of those years divided by the starting value, which in this case would be the 1998 value of 30,000,000. 180,000,000−30,000,00030,000,000∗100=500%\frac{180,000,000 - 30,000,000}{30,000,000} * 100 = 500\%.

  • Identify one negative human health effect other than death associated with the exposure to mercury: Mercury are all examples of heavy metals, And all heavy metals fall into this category of neurotoxins that cause neuro system damage and disrupt normal neurological function.

  • Laws involved with wastes

    • The Resource Conservation and Recovery Act or RCRA monitors the transport of hazardous waste from cradle to grave.
    • CERCLA, the Comprehensive Environmental Response Compensation and Liability Act. It creates a super fund to finance the cleanup of hazardous waste sites and compensates people who have been physically or economically harmed by exposure to that waste.

  • Experimental Design (Red Spruce Forest Acid Deposition Scenario):

    • Describe the effect of acid deposition on trees in a forest:
      • It can cause stress to the trees.
    • The dependent variable is the concentration of aluminum in the soil.
    • Explain how the results of the experiment would change if the soil sample had a high concentration of limestone:
      • The limestone would buffer the effects of acid deposition because it is a base and therefore the pH would be neutralized.

  • Trends by reading graphs:

    • Based on the data in the graph, describe the trend in the pH:
      • The pH increased, so it became less acidic.
    • In 02/2001 was the year the highest coal consumption was recorded.
    • Explain how the data in the graph would support the hypothesis that combustion of coal could be correlated to the damage of the Red Spruce Forest:
      • The combustion of coal actually decreased less coal, less SOx emitted, less SOx, less acid rain, increase in the pH.

Key Takeaways for FRQs

  • Focus on task verbs.
  • Know experimental design steps.
  • Review dependent and independent variables.
  • Interpret graphs and charts.
  • Understand pollutants' direct and indirect effects.
  • Identify pollution sources and reduction strategies.
  • Know sewage treatment steps.
  • Understand laws for preventing exposure to harmful substances.
  • Explain how pathogens cycle and expose us to diseases.