11-01: Humans and Our Environment

Environmental Issues, Overview

The Industrial Revolution

• Invention of the steam whistle
• Boom in industry
• Beginning of all environmental issues today

The Human Population

• Our population is growing (about 7 billion people now)
• With abundant resources populations of living things tend to increase exponentially
• The carrying capacity for humans has been drastically increased by technologies
  • Carrying capacity: particular ecosystems have certain numbers of resources, and in order to support life, everything needs sufficient resources to survive.
  • Because of advantages in medicine, food growth, technology, etc, we have the ability to live longer
• Our large population has a large impact on the environments we inhabit
• Technology has helped us live longer and helped the population grow at an incredibly fast rate

Tragedy of the Commons

• Shared resources are often collectively over used by many individuals and under maintained often depleting or spoiling the resource
• “It's just one _” attitude adds up. As individuals, out actions have an almost insignificant impact on the environment
• As a population the effects are massive and affect us all
• Everyone needs to do their part, every action does make an impact (whether that action be bad, good, or neutral)

Energy Tragedies

• Coal, oil, and natural gas extraction take a heavy toll on ecosystems
• Dams for hydroelectric power can devastate the environment they are in too

Waste Tragedies

• Limited landfill space
  • Eventually these will fill up- Increasing quantities of hazardous wastes, Single use plastics are major contributors

Agricultural Tragedies

• Pesticide and fertilizer use
• Soil degradation
• If not used carefully, all of these resources will used up

Monocrop Farming

• Monocrop farming: growing one plant at a time
• Sustainable farming: rotate crops and let the land “rest”
• An issue because we have the technology now to assess demand and to choose what to plant based on what will make the most money
• All of the resources used to grow that such a plant will be used up and in the long run it will harm the environment devestatingly

Overfishing

• Fishing practices aren't always regulated properly
• If we catch too many fish too quickly, the fish population will dwindle and won't reproduce properly

Biodiversity

• We don't know what will happen when things go extinct
• A balanced ecosystem requires equal amounts of predators and prey, as well as balanced resources

Deforestation

• Ultimately does impact humans and their comfort Species may not be able to survive in changing conditions because of deforestation Habitat and species loss We lose populations due to changing conditions’ Invasive species Habitat fragmentation

\

Environmental Contaminants

Pollution

• Pollution: when a human activity causes the release of a substance that harms the environment
• Pollutant: waste material from human activity that can cause harm to an ecosystem
• Environmental contaminants: are substances that can harm humans and other living things
• Pollutants and contaminants are types of environmental factors that affect our environment and both living and non living things

@@Air pollution@@

5 major gases considered to be air pollutants produced by human activities

1. Carbon Monoxide

• Toxic: removes oxygen from airways, suffocates humans by preventing them from breathing in oxygen
• A clear colourless odourless gas
• We get it from the partial burning of organic matter like gas, coal and wood
• Released from car exhausts and cigarettes

2. Sulphur dioxide

• One of the contributors that causes acid rain
• Smells like rotten eggs
• Produced by burning sulphur containing fuels

3. Nitrogen oxides

• Nitrogen is the most abundant element (air has ~78% nitrogen)
• One of the contributing factors to acid rain
  • Everything has a pH that tells us how acid or basic something is, rain water has a certain level of acidity and when exposed to certain things, its PH changes and thus it becomes acidic and then changes the nature of the soil (and plants have a low tolerance for acidity)
• Produced by burning fossil fuels

4. Particulate matter

• Tiny particles in the air that shouldn't be there, hard to filter out
• Range of particles that includes ash from factories, smoke from fires, soil and fertiliser from farming. Pollen, dust and mould are natural particulates
• Particulates can cause a range of health problems for humans
  • E.g. the people who helped clean up 911 dealt with this
  • Dust particles are less than 10 microns

5. Hydrocarbons

• Hydrocarbons come from fuels that can evaporate into the air
• From the air, they can react with nitrogen oxides in the presence of sunlight to produce photochemical smog, in particular, it's the nitrogen oxides
  • Smoke + Fog = Smog
• The mix of compounds in smog can damage plants and injure lungs
  • Nitrogen dioxide is in the air, Nitrogen oxides are formed when solar energy hits, and it mixes with water, when that mixture mixes with other chemicals, then they are left to be in the air

\n CFCs, Chlorofluorocarbons

• Comes from refrigerators, aerosol cans, air conditioners,
• Causes ozone in the upper atmosphere to break down - this allows for more UV light to reach Earth and cause issues (e.g. skin cancer)
• Ozone layer: protective layer blocking harmful rays from the planet
  • Ozone layer is thinning out

\

GHG, Greenhouse Gasses

• work

\

Workplace Chemicals

• Workplace chemicals such as herbicides, solvents and volatile organic compounds (VOCs) can also harm humans in an indoor or outdoor environment
• VOCs have been often used in paints
• WHMIS symbols warn of dangers

\

Pathogens

• Pathogens: harmful to humans (i.e. disease) that is transmitted from person to person (organic)
  • COVID is a pathogen
• Disease causing bacteria, viruses, single celled organisms and fungi can be transmitted through air, food or water
• Animals can also carry pathogens such as West Nile virus (bitten by a mosquito) and Lyme disease (bitten by a tick)
  • E.g.: Salmonella, E. Coli, etc.

\

Effects of Environmental Factors on Humans

Entering the Body

• Environmental contaminants can enter the body in many ways
• We can inhale it, it can be absorbed, we can eat it (ingestion), or it can be injected

\

Inhalation

• Your respiratory system ends with alveoli which can absorb inhaled contaminants
• Body secretes mucus and has cilia (hairs and little flaps of skin that are hair-like) to trap small amounts of many particles (e.g. bacteria, dust)
• We have no defence for pollutants like VOCs and pesticides

\
Respiratory System Harm

\

Ingestion

• Ingest: to eat, comes down to your digestive system
• Ingested contaminants can be absorbed by the digestive system
• Body defences include vomiting and blood filtration by the liver
  • When you ingest contaminants, you may vomit because the body wants to purge itself of the contaminants

Digestive System Harm

\

Absorption and Injection

• Skin is the first line of defence for our bodies. It contains protective layers but also capillaries that can absorb contaminants
  • Skin is the largest organ and it is a layer of protection for our bodies
• Oils, tar, cleaning products, and pesticides can all enter this way
• Pathogens like the West Nile Virus can enter skin by injection
  • Outer layer, inner layer, subcutaneous layer
  • Once the skin is breached, it can get anywhere in the body because it enters the bloodstream

Harm to skin

• Rashes, hives, itching, hair loss, burns, and skin cancer can come from exposure to environmental factors such as cleaning fluids, workplace chemicals, drugs, and radiation

Circulatory and Lymphatic System

• Workplace chemicals and pathogens like parasites can cause harm to your circulatory and lymphatic system
• Lymph is fluid found in spaces between cells. Bacteria and wastes are filtered out at lymph nodes and by spleen \n

Nervous and Reproductive Systems

• Pesticides, workplace chemicals, antiseptics, bacteria and viruses, etc. can cause damage to brain, spine, and nerves
• Sperm, eggs, and sex organs can be damaged or result in cancers caused by environmental contaminants as well
  • Meningitis: inside the brain there is an area called the meninges. There are no sensors on the brain for touch, but if a bacteria gets there then it can become swelled and eventually may lead to death

\

Protection from Environmental Factors

Measles

• Measles is a childhood infection caused by a virus pathogen that lives in the mucus of the nose and throat
• It is very contagious - even before symptoms like the rash show up
• Measles infections afflict 20 million people every year and results in 100 000 deaths per year
• Symptoms: runny nose, cough, tiredness, loss of appetite, fever, sensitivity to light, spots all over the body and inside mouth, conjunctivitis (pink eye)

\

Vaccine protection

• Vaccines can protect humans from many pathogens like the measles
• They work by exposing your body to weakened forms of a microbe so that the body can learn to fight off an infection
  • White blood cells or antibodies (soldiers) learn to fight this
  • Antibodies are very specific
• If a certain number of people are vaccinated against a disease then the whole group becomes less likely to get it
  • This is called herd immunity
• Recent anti-vaxx movements have endangered many lives unnecessarily
  • They claim that they can cause Autism and other negative effects
  • Anti mask rallies and protests
  • “This years flu strain is 65% effective” →  means that you are either 100% or 0% protected, certain people will be protected and others will not - on average 65/100 will be protected and the other 35 will not be

\

Medication

• Asthma reactions triggered by environment can be treated with medication
• Antimalarial medications can kill the parasites that can cause malaria to protect a person from the disease
• No medication or vaccine is 100% effective \n

Non Medical Protection

• Sunscreen and UV protective clothing can protect humans from UV light that can burn skin - the sun protection factor (SPF) tells you how effective it is

\

Air Purifiers

• Pollutants on the air can be removed by air purifying respirators
• Really toxic environments may need a supplied air respirator
  • After 911, people tried to clean up the rubble without protection and they are sick because of what they inhaled \n

Hand Washing

• The most effective way to prevent the spread of disease is to wash your hands
• No need to buy a special antibiotic soap
• Soap forms a reaction with certain particles and so when you wash away the soap you wash away the new compound (thus washing away the bacteria and other icky things on your hands) \n

Safe Food Handling

• Every year ~12 million Canadians get a food borne illness such as botulism which is caused by a bacterium that can live in improperly preserved food
• Food poisoning -  eating food that hasn't been prepared properly will make you sick
• Very important to know how to handle things
• Step 1: clean - protects by getting rid of any bacteria that could be harbored on your fingers
• Step 2: separate raw meat from other food when preparing it - don't eat meat raw
• Step 3: cook your food - don't eat anything that you shouldn't at a level of underpreparedness
• Step 4: chill your food - bacteria cannot thrive when it's too cold and it will slow down their growth - the colder it is, the slower bacteria growth
  • If you cook it for a certain amount of time over a certain amount of heat then this will also keep your food safe as most bacteria can't exist over a certain temperature

\

Indoor Air Quality

Canadians spend ~ 90% of time indoors

• Smoke: fireplaces, wood burning stoves, cigarettes, etc. all release particulate matter
• Poor circulation: airtight homes, dirty air in HVAC systems, attics, basements, etc. all remain in the home
• Toiletries: aerosols, lotions, vinyl shower curtains, airborne chemicals
• Mold: bathrooms and kitchens, always test
• Cooking: high level of particles
• Candles and electronics: release toxins that can lead to headache, fatigue, etc
• Cleaners and detergents: VOCs
• VOCs: toxic vapours that are gassed off of manmade materials (e.g. furniture, bedding, carpets)
  • Certain homes have filters to combat this

\
\

Human Effects on Ecosystems \n

Carbon Footprint

• The use of fossil fuels since the industrial revolution have massively increased the amount of CO2 and other GHG emissions into the environment
• Deforestation also increases the amount of carbon as trees are carbon sinks

\

Primary and secondary footprint

• Primary carbon footprint measures GHG emissions from burning fuels for energy and transportation
• Secondary carbon footprint measures GHGs from food, products, and services you buy
• Everything has a carbon price tag

\

Footprint cause and effect

• Some countries produce more GHG than others
• Effects of climate change including fires, drought, and extreme weather often affect poorer people and countries more than wealthier people and countries

\

Oil Spills

• Humans spill oil in marine ecosystems which can be devastating
• Oil spills on land can also end up in freshwater ecosystems like lakes, rivers, and wetlands
• Less dense parts of oil float and form a thin layer called a slick
• More dense parts of oil sink and form tar balls that can wash ashore long after a spill
  • Use kerosene to get the oil spills off you when swimming

\

Effects of Oil Spills

• Seagrass and kelp can be covered and killed by oil
• Animals that depend on these plants for food and shelter also die
• Animals can be smothered by oil or be poisoned by ingesting it
• Oil also mats down fur and feathers of mammals and birds which can cause the to freeze to death and reduce their ability to swim, float, or fly \n

Acid Precipitation

• Humans produce massive amounts of gasses that make acid rain or snow
• Acid precipitation can be episodic or chronic
  • Snowmelt vs. Water bodies that are permanently acidic
  • We pump in gasses like sulfur dioxide and nitrogen oxides
    • Chronic: always precipitation is acidic
    • Epositic: something precipitation is acidic
    • If it falls down as snow, the snow will melt and then run off, some changes are more permanent (e.g. if the water is completely acidic then it will have drastic impacts) \n

Effects of Acid Precipitation on Soil

• Reduces basic nutrients such as calcium and magnesium from soil by leaching
• Loss of these nutrients slows down plant growth and makes them more vulnerable to insects, diseases and drought
• Increases levels of heavy metals in soils such as aluminum; these metals can be toxic to fish, plants, birds, and other animals
• Rocks in many Ontario ecosystems can not neutralize the acid and can result in dead lakes like in Killarney

\

Non Native Species

• Native species are adapted to live in the climate, soil, water and with the other creatures found naturally in their habitat
• Non native species are introduced by humans into new habitats where they are normally not found. This happens due to travel, agriculture, perts, live bait use, etc. \n

Effects of invasive species

• Invasive species are non native species that harm native species by competing with them for resources, they may also lack predators and their population can grow quickly

  • E.g. purple loosestrife: In the early 1800’s people brought it over from Europe for its pretty flowers and medicinal uses.  Here it has taken over many wetlands and outcompetes other plants like milkweed and cat tails which also impacts the animals that would eat them for food!

  \n

Monitoring the Environment

\

Sampling and monitoring

• In order for us to address environmental issues scientifically, we need info
• Soil, water, & air can be sampled and monitored over time to determine if changes are happening \n

Soil Sampling

• Soil core sample is a common way to measure the quality of soil to be used for agriculture
• Soil exists in layers called horizons
• At a lab, the technicians will measure components such as phosphorus, potassium, magnesium and nitrogen

\

Water sampling

• Water is also sampled at different depths to monitor the amount and location of different pollutants
• Drinking water is also sampled constantly by towns and cities

Drinking water tests

• Microbiological tests: bacteria or coliforms are living things that could be harmful to humans
• Chemical tests: chemicals like nitrates or lead might indicate contamination from sewage or rusty leaking pipes
• Radiological tests: some places have natural levels of uranium that must be monitored
  • We have a certain amount of radiation that were exposed to daily - the level must be considered

\n Air sampling

• Industrial plants often release exhaust from smokestacks that are monitored for emissions of sulfur, mercury, and carbon
• Particulate matter is also closely monitored because of its effects on human health

Air quality index

• In ontario, the AQI provides information about levels of smog in the air
• Air monitoring stations throughout the province provide data on 6 key air pollutants, and meteorologists update the AQI hourly
• If the AQI gets really bad they will issue a smog alert to the public

\

Ice core samples

• Places where ice has been accumulating for thousands of years can provide air and water samples about conditions in the past
• Plant pollen shows species that were alive
• Ice crystal shape is related to temperature and humidity
• Air bubbles show levels of oxygen and CO2

\

Quadrat Sampling

• Biodiversity can be measured by counting the number of each species found in a square of a given size
• Measures how well things are growing in a given area \n

Environmental Impact Assessment

• This is a study done before a project that may affect the environment
• Factors include whether the project may impact aquatic species, migrating birds, Indigenous uses

\

Scientific Environmental Solutions

Rapa Nui

• Isolated island alone in the pacific ocean
• Natives cut down palm trees to build canoes & monuments to their gods
• New palms couldn't grow due to rats
• Eventually, the last palm was cut and the population collapsed
• Often viewed as a cautionary tale for us on this little earth on vast space
• Consequence when nations are not sustainable

\

Our environmental issues

• Just like in Rapa Nui we must understand the problems we have
• We have a variety of growing environmental problems that could drastically affect our way of life if not dealt with effectively
• Informed citizens can act to make changes that will address these problems in a scientific way

\

Evidence

• All claims about environmental issues start with evidence
• Monitoring levels of pollutants/number of species in a given area will show changes over time that can inform our decisions
• We don't know what progress could stem from having these animals go extinct

\

Theories and models

• Predictions can be made about the future using theories about how the world works
• New theories displace older ones when new evidence is found
• Compute models use theories to make long term predictions about complex data
  • E.g. geocentric VS. heliocentric ways of thinking
  • Science can be used to prove a theory wrong

\

Paradigms

• In order to motivate and change people’s mindsets - we need to get people to think differently
• Many cultures act as if infinite development as growth is their goal/that humans are separate and above their environment
• The traditional Indigenous paradigm of connectedness of all things and sustainability is different
  • Current sustainability model: economy, people and nature are separate and dealt with differently
  • Other ideas view nature as most important - e.g. Indigenous POV’s

\

Paradigm Shift

• Most business models and governments have a very short term view
  • How do I make money now? How do I get elected now?
• A longer term view is needed for long term survival & sustainability \n

Critical thinking

• The skills that we should be developing from school
• To solve environmental problems, we must be critical thinker who can seek new facts, learn new skills, form new ideas to test
  • Reasoning
  • Evaluation
  • Problem solving
  • Cycle of critical thinking

\

Technological Advances

• Critical thinkers have produced new technologies that can help with many environmental problems
• Renewable energy
• Only works in some conditions
• Must be able to store energy for when it can't collect the energy
• Takes up a lot of space
  • Solar panels
  • Taking food scraps and isolating them - composting
  • Composting: organic material decomposes and forms soil that can be used - the nutrients are recycled
  • Not everything put in the “blue bin” is recycled - only about 30-40% (e.g. bottles, bags, etc.)

\

Success stories

• Ozone depletion in the upper atmosphere was detected by satellite technology

• Aerosol CFCs were banned in 1987 when it was determined that they were causing the loss

• Since then, the ozone levels have increased and continue to improve

  • Freeon used to release CFC, it worked well at cooling things down (e.g. fridges, coolers, AC)

  \n \n

\