Climate Change and Health
- What is climate change?
- Why is climate change happening?
- What can we do to reduce the pollution that causes climate change?
- How does climate change affect our health?
- Sickness from heat
- Sickness from poor air quality
- Food and water contamination
- Infectious diseases from insects, ticks and rodents
- Mould and bacteria
- Who is at risk?
- How can we protect ourselves?
- Where can I get more information?
What is climate change?
Climate change is a permanent change in weather patterns over time. This change in weather patterns can impact human health.
Changes include more frequent severe weather events such as:
- extreme heat
- extreme rain or snowfall
- extreme drought
- severe storms
Why is climate change happening?
- Climate change is caused mostly by the burning of fossil fuels (oil, gas and coal), which releases pollutants called greenhouse gases into the atmosphere.
- These pollutants trap heat from the sun, which has lead to an increase in the earth's temperatures.
- Changes in temperature affect ocean currents, air movement, evaporation and precipitation – all factors that affect the weather.
- Most experts agree that average global temperatures could rise by 1 to 6.5°C over this century.
What can we do to reduce the pollution that causes climate change?
There are many things we can do to reduce the emissions of pollution that cause climate change, such as walking or taking transit instead of driving your vehicle. The City of Toronto's Livegreen initiative provides many programs to assist in taking actions to protect the environment. Toronto Public Health's 20/20 The Way to Clean Air Campaign helps Torontonians reduce energy use at home and on the road by 20%.
How does climate change affect our health?
Climate change can have both a direct and an indirect impact on human health. These potential health impacts include:
Sickness from Heat
Extreme heat may cause:
- heat stroke, heat cramps and heat rash
- worsening of existing medical problems, such as asthma and allergies.
There are many things you can do to protect yourself from heat.
Toronto Public Health and its partners have conducted research and prepared reports on protecting vulnerable people from health impacts of extreme heat and mapping health vulnerabilities to heat.
Sickness from poor air quality
Extreme heat contributes to air pollution. Increased air pollution causes:
- eye, nose and throat irritation
- shortness of breath
- worsened respiratory conditions and cardiovascular disease
- increase in risk for certain types of cancer and premature death.
The Air Quality Health Index is a tool designed to help protect from poor air quality.
Food and water contamination
Storms and flooding may contaminate food and drinking water, which may lead to illnesses such as diarrhoeal and intestinal diseases.
Water and food-borne illnesses also increase when food is not refrigerated. Extreme heat events may cause Torontonians to use their air conditioners more, which may cause power outages. There are many things that can be done to ensure food safety during a power outages and floods.
Infectious diseases from insects, ticks and rodents
Climate changes can increase infectious diseases passed on by insects, ticks and rodents in three ways, by increasing the:
- amount of insect carriers (rodents, etc.);
- length of transmission cycles (i.e. longer spring); and
- the immigration of insect carriers to new regions.
These changes may lead to new diseases as well as the return those that were previously wiped out. For example, Lyme disease (a disease that comes from ticks) is likely to increase. Although Lyme disease is currently uncommon in Canada, changes in temperature may cause an increase in the tick population and expand the geographical areas in which they live. Lyme disease may cause long term complications such as nerve damage and vision problems.
West Nile Virus is another disease passed on through insects.
Mould and bacteria
Climate change will lead to increased flooding. Homes or buildings that are filled with flood or storm water or are exposed to a lot of dampness for a long time will have an increase in mould and bacteria growth. For some people, exposure to mould and bacteria can contribute to illnesses, such as:
- respiratory distress
- eye and nasal irritations
- flu-like symptoms
- asthma and allergy initiation and aggravation
There are ways to prevent mould from growing in your home.
Who is at risk?
We all are. However, certain populations are at greater risk of climate change health impacts. This is due to:
- exposure (e.g. a person with poor or no housing may have increased exposure during an extreme weather event);
- sensitivity (someone with respiratory illness may be more sensitive to air pollution than others); and
- inability to adapt to climate change (older people have a lower capacity to adapt to natural hazards to due to limited mobility).
Vulnerable groups include:
- infants and children
- people with underlying health problems
- low income and homeless people
- people living off the land
- First Nation communities
Toronto Public Health and the Clean Air Partnership have written a report on climate change and health equity.
How can we protect ourselves?
A certain degree of climate change is unavoidable. By preparing for the expected changes in weather, we can minimize environmental, economic and social impacts of climate change.
For example, Toronto Public Health's Hot Weather Response Program helps people prepare for and cope with hot weather.
Where can I get more information?
- Read Toronto Public Health's reports and publications on climate change.
Last updated July 2011