Pollution and Water Quality Analysis

Pollution

• Pollution is any alteration to the environment producing a condition harmful to living things.
• Pollution sources can be categorized into point sources and non-point sources.
• Point sources are small, defined areas causing pollution.
• Non-point sources are wide areas, not easily defined, where pollution originates or where its effects are seen.

Dilution and Concentration

• Dilution means pollution is becoming less concentrated.
• Factors that can dilute pollution include increased water flow in a stream or more air in the atmosphere.
• Factors that can concentrate pollution include stagnant water or weather patterns.

Water Quality

• Water quality in Canadian rivers, national and by land use, was analyzed from 2016 to 2018.
• Percentage of sites with different water quality rankings are shown for categories like Excellent, Good water quality, Fair water quality, Marginal water quality, and Poor.
• This data reveals various patterns according to land usage categories including agriculture, forestry, mining, populated areas, mixed pressures, and undeveloped areas.

Aquatic Environments

• As pH increases, the diversity of all organisms will decrease.
• Chemical factors affecting organisms include dissolved oxygen, pH, heavy metals, plant nutrients (nitrogen/phosphorus), pesticides, salts (sodium chloride/ magnesium sulfate).

Water Quality Categories

• Water quality is categorized by the provincial and federal government in five categories.
• The different categories include Human Drinking Water, Recreation (ex. Swimming), Livestock Drinking Water, Irrigation, and Protection of Aquatic Life.

Biological Indicators

• Scientists use organisms living within water to determine water quality.
• Examples include fish, plants, worms, insects, plankton, and protozoa.

Microbiological Indicators

• Microscopic organisms (like bacteria) can cause health problems in water.
• Water samples are taken to monitor levels of harmful bacteria.
• Organisms' presence or absence in water indicates the quality of the environment.
• Macroinvertebrates (e.g., stonefly, mayfly, caddisfly, beetle) are used to indicate water quality.
• Good quality water has a variety of organisms, but more of those needing high oxygen levels.

Dissolved Oxygen

• Dissolved oxygen is essential for the health of aquatic life (insects and microorganisms).
• Factors influencing dissolved oxygen include temperature, turbulence due to wind speed of water, photosynthesis produced by plants/algae in the water and the number of organisms using the oxygen.

Quantifying Pollution

• Pollution concentrations are often reported as parts per million (ppm) or parts per billion (ppb).
• One part per million (ppm) means one unit of the element can be found in one million units of the solution.
• One part per billion (ppb) means one unit of the element can be found in one billion units of the solution.

PPM Calculations

• PPM is calculated by multiplying grams of solute by one million, then dividing by the grams of solution
• Example calculations are shown for determining the concentration of substances (like salts and oxygen) in specific solutions, using the formula ppm = (grams of solute /grams of solution)*1000000

Toxicity

• Toxicity is a measure of how poisonous a substance is.
• Mixing pesticides can create dangerous chemical combinations.
• Some pesticides remain in the environment, causing long-term effects.
• Modern pesticides are typically broken down after one growing season.

LD50

• LD50 refers to the lethal dose at 50%.
• The LD50 value is the amount of a substance that causes 50% of test animals to die.
• Various LD50 values are listed (in grams per kilogram) for different substances like Aspirin, Caffeine, Nicotine, Strychnine, and Botulinum toxin showing varying levels of toxicity.

Risk Management

• Many substances affect animals and humans differently.
• Animal tests can misrepresent human effects.
• Knowing a risk does not always imply it's unacceptable depending on the circumstances.
• All chemicals may cause harm depending on type, length and amount of exposure.

Additional Information

• Different types of air and water pollution exist, like chemical, physical, and biological.

• Air quality can be measured by the levels of pollutants and the amount of emissions

• Circumpolar winds spread pollution across the northern hemisphere, causing contamination hundreds of kilometers from the source.

• Gaseous pollutants include oxides of carbon, nitrogen, and sulfur, which cause greenhouse effects, respiratory diseases, and acid rain.

• Sulfur dioxide is a major air pollutant that often forms from burning sulfur-containing fuels. Scrubbers can reduce sulfur dioxide emissions.

• Carbon monoxide is a colorless, odorless gas produced by motor vehicles, fireplaces, and industrial processes, which is dangerous. Catalytic converters transform carbon monoxide into carbon dioxide.

• Ground-level ozone is formed from the breakdown of pollutants in the environment through sunlight or electrical discharges, is one type of air pollutant. Ozone damages lung and plant tissue.

• Greenhouse gases, such as carbon dioxide, cause a naturally occurring effect. Increasing levels of these gases caused by human activity is a global concern.

• Global warming is not solely caused by humans, and natural events also contribute (eg, volcanoes and forest fires).

• Biodegradation is a process where living things break down organic substances including pollutants. Microorganisms, like bacteria and fungi, actively break down these substances.

• Biodegradation is affected by various factors, such as temperature, soil moisture, pH, oxygen supply, and nutrient availability.

• Phytoremediation uses plants to reduce the concentration of harmful chemicals in soil or groundwater. Plants absorb and accumulate these chemicals. Afterward, plants are removed and either burned or composted.

• Techniques like Photolysis (breakdown by sunlight) break down some compounds, but the effects depend on whether the environment includes sunlight and how harmful the substance is.