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Questions and Answers
What is the definition of pollution?
What is the definition of pollution?
Which of the following correctly describes point source pollution?
Which of the following correctly describes point source pollution?
What does dilution of pollution refer to?
What does dilution of pollution refer to?
As pH increases in an aquatic environment, what effect does it have on biodiversity?
As pH increases in an aquatic environment, what effect does it have on biodiversity?
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Which of the following is NOT a category under which water quality is set by the government?
Which of the following is NOT a category under which water quality is set by the government?
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What is the concentration of sulfuric acid in the lake after a 50 L drum spills into 30,000 L of water?
What is the concentration of sulfuric acid in the lake after a 50 L drum spills into 30,000 L of water?
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What is the concentration of pee in parts per million when 70 mL is added to 1,000 L of solution?
What is the concentration of pee in parts per million when 70 mL is added to 1,000 L of solution?
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How much free chlorine is present in a swimming pool if a 20 mL sample contains 0.5 mL of free chlorine?
How much free chlorine is present in a swimming pool if a 20 mL sample contains 0.5 mL of free chlorine?
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What does LD50 refer to in toxicity measurements?
What does LD50 refer to in toxicity measurements?
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If Dwane the rat weighs 0.85 kg, what is the lethal dose required for it to possibly die from 0.50 mg of rat poison?
If Dwane the rat weighs 0.85 kg, what is the lethal dose required for it to possibly die from 0.50 mg of rat poison?
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Which of the following statements is true regarding pesticides?
Which of the following statements is true regarding pesticides?
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How is toxicity measured in terms of poisons?
How is toxicity measured in terms of poisons?
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Which of the following describes a risk associated with mixing different pesticides in water systems?
Which of the following describes a risk associated with mixing different pesticides in water systems?
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Which organisms indicate good water quality by their presence in higher numbers?
Which organisms indicate good water quality by their presence in higher numbers?
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What is the primary purpose of measuring microbiological indicators in water?
What is the primary purpose of measuring microbiological indicators in water?
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What does a higher concentration of dissolved oxygen in water indicate?
What does a higher concentration of dissolved oxygen in water indicate?
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What is a common unit used to express pollutant concentrations in water?
What is a common unit used to express pollutant concentrations in water?
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If 0.01 gram of a chemical is dissolved in 1,000 grams of solution, what is its concentration in ppm?
If 0.01 gram of a chemical is dissolved in 1,000 grams of solution, what is its concentration in ppm?
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What factor does NOT affect the levels of dissolved oxygen in water?
What factor does NOT affect the levels of dissolved oxygen in water?
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What is the solute in a solution of salt dissolved in water?
What is the solute in a solution of salt dissolved in water?
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Which of the following indicates poor water quality?
Which of the following indicates poor water quality?
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What is the maximum dosage of poison that a 0.85 kg rat can tolerate without risk of death?
What is the maximum dosage of poison that a 0.85 kg rat can tolerate without risk of death?
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For a 1.75 kg duck, how much arsenic can it tolerate before reaching its LD50?
For a 1.75 kg duck, how much arsenic can it tolerate before reaching its LD50?
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What is the lethal dose of caffeine for a 55 kg person using an LD50 of 175 mg/kg?
What is the lethal dose of caffeine for a 55 kg person using an LD50 of 175 mg/kg?
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How many cans of Monster Energy Drink could theoretically be lethal to a 55 kg person at an LD50 of caffeine of 175 mg/kg?
How many cans of Monster Energy Drink could theoretically be lethal to a 55 kg person at an LD50 of caffeine of 175 mg/kg?
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What is the maximum recommended daily caffeine intake for adults to avoid unpleasant side effects?
What is the maximum recommended daily caffeine intake for adults to avoid unpleasant side effects?
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What does LD50 represent in toxicology?
What does LD50 represent in toxicology?
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Why might tests on animals not be reliable for determining human toxicity?
Why might tests on animals not be reliable for determining human toxicity?
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What is the primary risk associated with substances that have the potential to cause harm?
What is the primary risk associated with substances that have the potential to cause harm?
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Study Notes
Pollution
- Pollution is any alteration to the environment causing conditions harmful to living things.
- Pollution sources can be categorized as point source (small, defined area) or non-point source (wide area, poorly defined).
- Examples of point sources include city streets and factories.
- Examples of non-point sources include rural homes, cropland and animal feedlots.
- Dilution reduces pollution concentration.
- Factors like wind and water speed affect pollution dilution in the air or water.
Dilution and Concentration
- Dilution means pollution becomes less concentrated.
- Stream pollution can be diluted by increased water flow.
- Air pollution can be diluted by wind.
- Factors concentrating pollution include stagnant air or water, and geographic features that trap pollutants.
Water Quality
- Water quality in Canadian rivers (2016-2018) shows varying quality with different land use categories (agricultural, forestry, mining, populated areas, mixed pressures and undeveloped).
- The percentage of excellent, good, fair, marginal and poor quality water sites are visualized for different categories using graphs.
Aquatic Environments
- Pure water (H₂O) comprises only water molecules.
- Real-world water contains dissolved oxygen, pH, heavy metals, plant nutrients (nitrogen/phosphorus), pesticides, salts (sodium chloride/magnesium sulfate).
- Higher pH decreases biodiversity in organisms.
- Water quality is categorized by provincial and federal government in five areas: human drinking water, recreation (e.g., swimming), livestock drinking water, irrigation, and protection of aquatic life.
Biological Indicators
- Scientists use organisms (fish, plants, worms, insects, plankton, protozoa, viruses) to assess water quality.
- Macroinvertebrates (like stonefly, mayfly, caddisfly, beetle) indicate good water quality, as they require high oxygen levels).
Dissolved Oxygen
- Dissolved oxygen is essential for aquatic life (insects, microorganisms).
- Levels of dissolved oxygen depend on multiple factors:
- Photosynthesis levels by plants/algae.
- Water temperature.
- Water turbulence due to wind or water speed.
- Number of organisms using the oxygen.
Quantifying Pollution
- Pollution concentration is often expressed as parts per million (ppm) or parts per billion (ppb).
Measuring Chemicals in the Environment
- Parts per million (ppm) indicates the number of units of a chemical present in one million total units.
- Parts per billion (ppb) indicates the number of units of a chemical present in a billion total units.
Toxicity
- Toxicity refers to a substance's degree of poison.
- Mixing pesticides can create dangerous combinations of chemicals.
- Some pesticides persist in the environment and have long-term effects.
Measuring Toxicity (LD50)
- LD50 (lethal dose 50%) is the amount of a substance that causes 50% of test animals to die if given in a specific dose.
- LD50 values vary greatly between different substances and can be used to assess relative toxicity. Substances like water, aspirin, caffeine, nicotine and strychnine have different LD50 values.
Risk Management
- Effects of substances can differ between animals and humans.
- Animal testing to determine toxicity can have limitations, and may not accurately reflect the human toxicity.
- Acceptable risks depend on the situation.
- Chemicals can cause harm depending on type, duration, and quantity of exposure.
PPM Practice
- PPM (Parts per million) calculation example: Given a volume of pollutant and a volume of water, calculate ppm.
- Various examples of how to calculate ppm from different word problems, including scenarios involving accidents that cause pollution.
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Description
Test your knowledge on pollution and its impact on the environment with this quiz. Explore various concepts such as point source pollution, dilution effects, and water quality standards set by the government. Challenge yourself to understand how changes in pH can affect biodiversity in aquatic ecosystems.
