B. Life Systems · Human Organ Systems

What Affects Our Health? Social and Environmental Factors

B1.1 A1.1 A3.1About 45 minutes

Learning goals

I can name social and environmental factors that affect human health.
I can assess whether a factor is helpful or harmful and explain why.
I can describe ways to reduce harmful effects and take advantage of helpful ones.
I can investigate health factors in my own community.

Words to know

factor
Something that has an effect on something else.

environmental factor
Something in our surroundings, such as air, water, sun, noise or green space, that affects health.

social factor
Something about our relationships, community or way of life, such as friends, family, income or access to health care, that affects health.

Air Quality Health Index (AQHI)
A Canadian scale from 1 to 10+ that tells how risky the air is for health. Higher numbers mean more risk.

UV Index
A scale showing how strong the Sun's ultraviolet rays are. At 3 or higher, protect your skin.

well-being
Being healthy and well in body, mind, feelings and spirit.

Same body, different places

Imagine two kids with the same healthy body. One lives near a park with a playground, clean air and friends nearby. The other lives beside a busy highway, with no safe place to play. Which one finds it easier to stay healthy?

Your health doesn't only depend on your organs. It also depends on the world around you and the people in it. These are called environmental factors and social factors.

Environmental factors

Air quality. Smog from traffic and smoke from forest fires can irritate the lungs, especially for people with asthma. Canada's Air Quality Health Index (AQHI) goes from 1 to 10+. From 7 to 10 the risk is high, and above 10 it is very high. When the risk is high, children and people with asthma or heart or lung problems are advised to cut back on hard outdoor activity.
Water quality. Clean drinking water keeps us healthy. Dirty water can carry germs that make people sick.
Sun. Some sunlight helps your body make vitamin D and lifts your mood, but too much UV can burn skin and harm eyes. When the UV Index is 3 or higher, cover up, wear a hat and sunglasses, use sunscreen and find shade.
Heat and cold. Very hot days can cause heat exhaustion; very cold Canadian winters can cause frostbite.
Noise. Very loud sounds can damage hearing.
Second-hand smoke and vapour. Breathing in someone else's smoke harms the lungs and heart.
Green spaces. Parks, trails and trees give places to play and can help people feel calmer. This factor is helpful!

A green neighbourhood park with a playground, tall trees and a paved walking path beside a pond. — A safe park with clean air and space to play is an environmental factor that makes it easier for people to stay active and healthy. AI-generated image

The AQHI scale: 1 to 3 is low risk, 4 to 6 moderate, 7 to 10 high, and above 10 very high. In the example below, Liam's town is at 8: high risk.

Social factors

Family and friends. Support from people who care about you helps your mental and physical health. Bullying and loneliness can harm it.
Access to healthy food. Some families have stores with fresh food nearby; others don't. In many northern communities, food must be flown in and costs much more.
Access to health care. It is easier to stay healthy when a doctor, nurse or clinic is nearby.
Income. Money affects the food, housing and activities a family can afford.
Community programs. Recreation centres, sports teams, libraries and school breakfast programs help.
Habits around us. If friends and family are active and get enough sleep, it is easier for us to do the same.

Canada's 24-hour movement guidelines for kids say: at least 60 minutes of heart-pumping activity every day, 9 to 11 hours of sleep a night for ages 5 to 13, and no more than 2 hours a day of recreational screen time.

One example of a day that meets Canada's 24-hour movement guidelines for kids: 9 to 11 hours of sleep, at least 60 minutes of heart-pumping activity, and no more than 2 hours of recreational screen time.

Indigenous perspectives on health

Many First Nations, Métis and Inuit people understand health as a balance of the physical, mental, emotional and spiritual parts of a person, and as connected to family, community, culture and the land. Being on the land, speaking one's language and sharing traditional foods and teachings are seen as part of being healthy.

Clean water is an important example of an environmental factor. Some First Nations communities in Canada have lived for years under drinking water advisories, which means their tap water is not safe to drink without boiling or is not safe at all. Communities, their leaders and governments are working to end these advisories.

Factor	Helpful or harmful?	How it affects the body	What people can do
forest fire smoke (AQHI 8)	harmful	irritates the airways and lungs	stay indoors with windows closed; choose indoor activities
a park nearby	helpful	more chances for exercise; heart and muscles get stronger	use it often; help keep it clean
UV Index of 7 in July	harmful	sunburn, damage to skin and eyes	hat, sunglasses, sunscreen, shade
a school breakfast program	helpful	nutrients and energy for learning	take part; thank volunteers
bullying	harmful	stress, worry, poor sleep	tell a trusted adult; be an upstander
very loud music in earbuds	harmful	can damage hearing over time	turn the volume down; take breaks

Assessing factors: is it helpful or harmful, and what can we do?

Worked example

Let's assess a factor

On a July day, the AQHI in Liam's town is 8 because of forest fire smoke. Liam has asthma and soccer practice outside tonight. What should he consider?

Identify the factor: smoky air (environmental).
Assess the effect: 8 is a high risk. Smoke irritates the airways and lungs. People with asthma are at more risk.
Which systems? Respiratory first; the circulatory system may also have to work harder.
Reduce the harm: skip or move practice indoors, keep windows closed, keep his inhaler nearby and follow his asthma action plan.
Take advantage of something helpful: do an indoor activity he enjoys, so he still gets exercise.

Liam should avoid hard outdoor exercise while the AQHI is high and follow his asthma plan.

Just for fun

Why are trees such great neighbours?

They give you shade, a place to play, and they make oxygen for free.

Hands-on activity

Community health investigation

You need: a notebook, a pencil, a grown-up. Optional: a weather app or website that shows the AQHI and UV Index.

Question: What factors in my community help or harm health?
With your grown-up, take a walk around your neighbourhood (or think about it if you can't walk).
Make a T-chart: Helpful (parks, bike paths, community gardens, library, rec centre, clinic) and Harmful (busy road, litter, places with smoke, no sidewalk).
Check the AQHI and UV Index for your area for 5 days. Record them in a table.
Choose one harmful factor. Write two ways people could reduce its harm. Choose one helpful factor and write how your family could use it more.

Grown-up note: stay with your child near traffic, and on smoky or very hot days, do this activity from indoors.

Your turn

What is the difference between an environmental factor and a social factor?

Is a nearby park a helpful or harmful factor? Explain.

The UV Index is 6. What should you do?

Which body system does smoky air harm most directly?

How many hours of sleep do the Canadian guidelines suggest for kids aged 5 to 13?

Name one way a person can reduce the harm of loud noise.

More practice: warm-up

Name one environmental factor that affects health.

Name one social factor that affects health.

What does a high AQHI number mean?

Is bullying a helpful or harmful factor?

How much heart-pumping activity should kids get each day?

More practice: on your own

Why might families in some northern communities find it harder to buy fresh fruit and vegetables?

How do friends and family affect health? Give a helpful and a harmful example.

Why can second-hand smoke harm someone who doesn't smoke?

Explain how a school breakfast program helps the digestive and nervous systems.

What does a drinking water advisory mean?

Challenge

Assess this factor: a new highway is built next to a school. Give one harmful and one helpful effect, and one way to reduce the harm.

Many First Nations, Métis and Inuit people see health as connected to the land and community. Give one example of how being on the land can support health.

Design a short survey question to find out how many hours your classmates sleep. How could the results help?

Check your understanding

Quiz

Which is an environmental factor?

Which is a social factor?

The AQHI is 9 and you have asthma. What is the best choice?

At what UV Index should you start protecting your skin?

Which factor is helpful for health?

Canada's guidelines say kids aged 5 to 13 should sleep...

For parents and teachers

Big idea: health is shaped by environmental factors (air, water, sun, noise, green space) and social factors (relationships, food access, health care, income, community). People can reduce harmful effects and make the most of helpful ones.

How to help at home:

Check the AQHI and UV Index together on a weather app for a week.
Talk about the helpful factors in your community and how your family uses them.

Common difficulties:

Seeing every factor as only good or only bad. Many factors (like sun or a new road) have both effects.
Blaming individuals for factors they can't control. Emphasize what communities and governments can do, too.

Sensitive topics: income, food access and drinking water advisories may be close to home for some families. Keep the focus on understanding and solutions.