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BIOL 381
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BIOL 381
L8 Pt. 1
Study
CEPA + goals
Canadian Environmental Protection Act, Reduce pollution Protect the environment Protect human health
CEPA: Air Pollutants Covered
Criteria air contaminants, Persistent organic pollutants (POPs), Heavy metals, Toxic air pollutants
Criteria Air Contaminant - Sulfur dioxide (SO2)
What: Smelly colorless gas How: Produced primarily from fossil fuel combustion
Criteria Air Contaminant - Nitrogen dioxide (NO2)
What: Smelly red-brown gas How: Fossil fuel Combustion
Criteria Air Contaminant - Particulate matter (PM)
What: Tiny solid or liquid particles How: Combustion, dust
Criteria Air Contaminant - Volatile Organic Compounds (VOCs)
What: Carbon compounds that are volatile How: Household chemicals, engine combustion, solvents, industrial processes
Criteria Air Contaminant - Carbon monoxide (CO)
What: Colorless, odorless gas How: Combustion of fuel, mostly vehicles
Criteria Air Contaminant - Ammonia (NH3)
What: Colorless gas that smells awful (urine) How: Livestock waste, fertilizer production
Criteria Air Contaminant - Tropospheric Ozone (O3)
What: Colorless gas that smells slightly sweet How: Secondary pollutant created from the interaction between sunlight, heat, nitrogen oxides, and carbon compounds
Persistent Organic Pollutants (POPs)
Organic compounds that are resistant to degradation/decomposition via biological, chemical, and photolytic processes (also volaile -- mainly anthropogenic sources)
POP - The Dirty Dozen
Pesticides: (aldrin, chlordane, DDT), Industrial chemicals: (hexachlorobenzene, polychlorinated biphenyls - PCBs), By-products: (dioxins, furans)
What are criteria air contaminants?
Pollutants for which maximum allowable concentrations have been established
What are persistent organic pollutants (POPs)?
Volatile compounds that have long residence times
What are heavy metals? What are the problems?
Highly dense metals (ex Hg, Pb), 1. Associated with particulate matter easily transported in the atmosphere 2. Toxic even in low concentrations 3. Can bioaccumulate
What are toxic air pollutants?
An 'all other' category that includes examples like asbestos and CFCs, methyl bromide.
L8, Pt 2
Study
Air Quality Health Index
Metric of air quality developed by the government ofCanada. Calculated based on relative risks of common air pollutants: Ozone, PM, Nitrogen Dioxide.
Industrial Smog (Def + Contains)
Produced from the incomplete combustion of coal or oil, containing CO₂, CO, SO₂, SO₃, H₂SO₄, (NH₄)₂SO₄. Grey in colour.
Photochemical Smog Contains
Produced from light-driven reactions between pollutants and atmospheric components, Containing NO, NO₂, VOCs, HNO₃, (O₃ -- when there is more h2o vapour), Peroxyacyl nitrates (PANs -- when there are more hydrocarbons)
Primary vs secondary pollutants
Primary pollutants are emitted directly into the atmosphere, while secondary pollutants are formed through chemical reactions in the atmosphere.
Outdoor air pollutants
Various substances that are released into the outdoor air and can cause harm to human health and the environment.
Tropospheric Ozone
A harmful pollutant that forms near the Earth's surface when nitrogen oxides (NOₓ) and volatile organic compounds (VOCs) react in the presence of sunlight.
Toxic Air Pollutants
Hazardous substances that can cause serious health effects, including cancer, reproductive disorders, neurological damage, and respiratory illnesses.
Smog
Mixture of air pollutants that form primarily over urban areas
Movement of Air Pollution and Weather
Air pollution can be transported over long distances by wind, affecting areas far away from the original source. Weather conditions, such as wind patterns, temperature inversions, and precipitation, can influence the movement and dispersion of air pollutants.
Outdoor Air Pollution and Non-Humans
Outdoor air pollution also has significant impacts on non-human organisms and ecosystems. It can harm plants, animals, and aquatic life, leading to biodiversity loss and ecological disruptions.
Air Pollution Movement / Global Distillation
Air pollution can be transported globally through a process called global distillation, where warm air rises and cool air falls, carrying pollutants dissolved in the warm air with it. This movement is influenced by atmospheric circulation patterns and can result in the long-range transport of pollutants to remote regions.
Factors influencing air pollution distribution
Factors such as topography, wind patterns (hadley, ferrel, polar cells), human activities, and the location of pollution sources can influence the distribution of air pollution in a region.
What happened in Beijing 2006? How does topography affect this?
Smog incident, where the effects were compounded by thermal inversion: a pocket of air pollution was formed when the slow, high pressure air was compressed and warmed --> sunk onto cold air (too dense to move) --> cold air below becomes trapped, and cold air above traps warm air.
L7, Pt. 1
Study
Environmental toxicology
The study of the environmental factors that influence the exposure of organisms to potentially toxic chemicals 1. how toxic chemicals cycle through the environment 2. Where chemicals may accumulate in the environment !How Chemicals react with the environment!
Ecotoxicology
The study of the directly poisonous effects of chemicals, in addition to their indirect ecological effects 1. how chemicals alter the species composition of an ecosystem 2. how chem. accumulation influences ecosystem processes !Impacts of chemicals on the environment and its inhabitants!
Acute toxicity
Short-term exposure to a chemical in a high enough concentration to cause biochemical or anatomical damages or even death
Chronic toxicity
Long-term exposure to low or moderate concentrations of a chemical, which over time may cause biochemical or anatomical damage or become lethal
How Toxicity is Measured
Often done by determining the LD50 - the amount of a compound required to kill half of a population of experimental animals. It is usually measured in terms of amount of chemical per unit body weight.
Dose-response curves
Curves that show the relationship between the dose of a chemical and the response or effect it produces in an organism. They often include the ED50 (effective dose 50), TD50 (toxic dose 50), and LD50 (lethal dose 50).
Threshold (end of tolerance)
The lowest dose of a drug in which it will have an effect (w/o death).
Relationship between survival of juvenile salmon and concentration of selenium in their tissues
10% reduction in maximum survival due to Se.
Synergistic Effects
Interactive impacts of toxins that are more than or different from the simple sum of their constituent effects. When toxins are combined, they can be more dangerous than when they are individually present.
Carcinogens
Substances that can cause cancer
Mutagens
Substances that can cause DNA changes and mutations
Teratogens
Substances that can cause developmental abnormalities in embryos or fetuses
Allergens
Substances that overwhelm immune systems
Neurotoxins
Substances that cause damage to the nervous system directly
Endocrine Disruptors
Substances that can interfere with the normal functioning of hormones in organisms
Example: Surface Water Pollution
An example of environmental pollution caused by human waste such as sewage
Decrease water pollution by...
decreasing agricultural runoff, improving wastewater management systems, and implementing stricter regulations for power plant cooling
Fate and Transport Modeling
The modeling and study of how pollutants move and spread in the environment
Movement of pollutants
Source (power plant)-> dispersal -> precipitation/deposition -> aquatic food web -> consumption of contaminated water AND/OR from dispersal ->leaves -> soil/terrestrial food web
Persistent Organic Pollutants (POPs)
Organic compounds that are resistant to degradation or decomposition via biological processes and photolytic (light) processes (ex: pesticides, industrial chemicals, by-products)
Bioaccumulation
The accumulation of contaminants in the tissues of organisms (polychlorinated biphenyls - pcbs starts here)
Biomagnification
The process by which contaminants in the tissues of organisms reach higher concentrations as they move up the food chain (pcbs end here)
Global Distillation Effect
Also known as the 'Grasshopper effect,' it refers to the phenomenon where pollutants are transported by water/air and enter colder areas (like mountains)
L7, Pt 2.
Study
Environmental Impact Assessment
A study of the potential impacts of a project/activity on the environment -- when in doubt, protect people and the environment
The Precautionary Principle
In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.
Environmental Risk Assessment
Quantitative: Evaluation of risks associated with some sort of hazard in the environment. 1. Likelihood of encountering it, 2. Likely intensity, 3. Biological damage predicted from exposure
Example of tracking change on the short term
Quantifying the amount of algae in a river upstream and downstream from a pipe discharging water from a municipal waste treatment facility (easier)
Long term tracking of environmental change: paleoecology
1. Uniformitarianism: the present is the key to the past. 2. Analogy: Application of modern organismic features to ancient organisms (purpose: conservation, restoration, decision making practices)
Paleolimnological approach
Select lake -> select coring site and retrieve sediment core -> section and date core -> sub-sample sediments and isolate indicator of interest -> collect indicator data -> analyze data (sediments change seasonally so they record time passage easily)
Environmental Indicators from aquatic systems
Diatoms, chrysophytes, (2x algaes) chironomids (insects)
Environmental Indicators from the land
pollen, mineral particles (Abundance can be an indicator), insect remains
Environmental Indicators from the atmosphere
carbon particles from carbon combustion, fly ash from coal combustion, metals and other pollutants from industry
Example of Dose-Dependent Experiment or mesocosms
Chambers that isolate parts of the lake, different acids are applied and studied
The Whole Ecosystem Experimentation Approach
Experimental Lakes Area (ELA): Add P to lake -> divide in 2 parts, -> add nitric acid (observe u shaped acidification/recovery graph)
Hubbard brok experimental forest
Forest equivalent of ELA
Tested by increasing CO2 in air
L5
Study
Causes of Water Scarcity
Hydroelectric Dams, Bad Planning, Wasted Irrigation
Hydroelectric Dams
Cause water scarcity by disrupting natural flow of rivers and blocking water access downstream
Wasted Irrigation
Loss of water due to inefficient irrigation practices and growing water-intensive crops (cotton, rice, sugarcane)
Renewable resource: Soil
1. Fertility (nutrient content) cycles 2. Organic matter cycles
Soil problem: Erosion
Caused by overcultivation, overgrazing, and poor forestry practices, resulting in loss of fertile soil and water runoff
Soil problem: Salinization
Accumulation of salts in soils due to excessive irrigation and/or excessive fertilizer use
Nutrient/Organic matter Cycling: Best Practices
Cycle fields + fallow years, plant cover cropping (protect soil w plants), leaving crop residuals (organic matter supply), No-till farming (decrease top layer disturbance)
Clear Cutting: Def., Purpose, Issues
Deliberate removal of all trees from an area, usually for harvesting: can be similar to deforestation if not done properly!
How to Decrease Deforestation
Vote with your dollar, support shade-grown coffee, reduce palm oil consumption, buy products certified by RSPO and RTRS, eat less meat, and buy Fair Trade products
Problem in Silviculture
Whole tree harvest depletes nutrients, Short rotation (50 yrs) depletes soils, Big cuts can lead to mass leeching of nutrients
Solution in Silviculture
Stem only harvest leave residues, Implement longer rotations (100 yrs), Harvest smaller areas mixed with untouched areas (buffers), Plan roads around streams, install appropriate sized culverts, Limit Harvest of Old Growth Forests (Very high biodiversity and number of endemic species)
Renewable resource: Fish (problems)
Eat too much/over-harvested, huge increase in aquaculture (cultivating semi-domesticated fish)
Problem: Bottom trawling
huge nets catch a ton of bottom-dwelling sea organisms
Problem: Bycatch
One of the biggest threats to maintaining healthy fish popn.s and ecosystems: non-target organisms caught and kept or thrown overboard while dead/dying
Problem: Fishing down the food web
Overfishing of subsequent food web levels, till only base of pyramid is left.
Risks: High Impact Aquaculture
(huge net introducing environment for organisms in the ocean, including non-native species and antibiotics) -- overuse of antibiotics for fish, lead nets are harmful for fish, risks escape of invasive species, leaves behind fish sewage, high concentration of fish can cause disease, etc.
Solution: Low impact aquaculture
recreate natural habitat in each tank, recirculating the aquaculture systems
