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Present health departments are aware of these issues as existing health risks. The key climate change-health issues can be summarized as temperature extremes, extreme weather events, vector and rodent-borne diseases, air quality including indoor environments, UV radiation, and water and food borne diseases. The government of Canada has established a Climate Change and Health Office (CCHO) to help Canadians better understand the health impacts of climate change. The CCHO works in collaboration with researchers across Canada and provides advice to health care partners in provinces, territories and communities. Studying what to do to meet the impacts of climate change is important. Research and preparations to undertake adaptations of the present system are needed. See 6.2.2e for future strategies that focus on assessment of risk, preparedness and adaptation to meet the challenges of change.
WEB Links and resourcesCanada Climate Change and Health Office Canadian Public Health Association Health Effects of Climate Change
and Air Pollution Canadian Association of Physicians for the Environment (CAPE) University of Western Ontario Ecosystem Health Program Global Climate
Change and Health Temperature extremes The temperature graph below helps put Ontario into context for the global picture as a region of Canada. Departures from the average mean are used as a method of measuring change.
Source: Adapted from Zhang et al, 2000. Canadian Council of Ministers of the Environment (2003) Climate, Nature, People: Indicators of Canada's Changing Climate www.ccme.ca The graph shows the difference between each year's average temperature and the average for 1961 and 1990. The dark line smooths out the year to year differences to show the general pattern over time.
See sections 5.2.1 Ontario for present weather patterns and recent extremes. and 6.2.1 for future extreme weather, temperature and precipitation Heat Stress An increase in annual temperatures with higher minimums may cost more lives due to heat stress. This is already being felt, especially in urban areas, which have a higher annual temperature than the rest of Ontario. Heat stress is even more serious when combined with increased air pollution and humidity. During extreme hot summers the death rate from heat stress for the elderly increases from 7 per 100,000 to over 66 per 100,000. The "urban heat island effect" the tendency of cities to retain the sun's heat when vegetation is removed and replaced with pavement and buildings -- will make this situation worse in many of our cities. Under climate change the number of days that exceed the 33oC heat stress threshold could increase from between 21 to 50 days. The minimums for summer nights are the key factor. These minimums are already increasing. The good news is warmer winters. Temperature extremes in winter and summer are responsible for more deaths than are extreme weather events such as tornadoes, blizzards, or floods.
For extreme weather events such as flooding, snow or ice storms and drought see section 6.2.1 Lower water levels may result in more boil water notices. Spills or small amounts of pollutants will have a greater concentration when water levels are lower. Contaminants are often when measured in parts per million. Extreme events, such as flooding, leave behind great growing conditions for moulds in the buildings whether homes or commercial or industrial complexes In extreme events such as heavy rain in a short time, municipalities may have to allow raw sewage to mix with excess runoff to lakes and rivers to avoid flooding or sewer backups e.g. Peterborough July 2004. See the cost of natural disasters and insurance in 5.2.2d. Air Quality Most air pollutants come from the burning of fossil fuels in vehicles, factories, power plants and home furnaces. Some air pollutants injure plants and reduce crop yields and forest growth. Air pollution can irritate the eyes, reduce lung capacity and worsen respiratory diseases. Research how the number of hospital admissions changes on smog days in Toronto.
Fossil fuels are carbon-based molecules that have been stored as oil, coal, natural gas. Carbon is also temporarily stored as carbon dioxide dissolved in the oceans or sequestered as carbohydrates in plant cell walls, starches, fibres, wood or peat. Limestone stores carbon as calcium carbonate. The carbon cycle is completed when carbon dioxide is released into the air when plants and animals respire, decay or are burned. Humans overload the carbon cycle by burning more fuels, especially fossil fuels, producing more carbon dioxide than the terrestrial and aquatic ecosystems normally absorb or are able to recycle.
Levels of airborne particles vary depending on the region, both local and distanced emissions and the season. Ground level ozone, airborne particles combine with other air pollutants to produce smog, especially in summer with higher UV levels. Other air pollutants include nitrogen oxides(NOx) sulphur dioxide (SO2) ammonia (NH3). Particulate matter, often carbon-based, that are also released in emissions influence global temperatures by changing the albedo affect of the planet. Atmospheric studies after the eruptions of volcanoes help understand these effects. Fine particles are those with diameters less than or equal to 2.5 micrometers(PM2.5). These are the greatest threat to human health because they travel deepest into the lungs. Monitoring methods for fine particulates have been changed but many areas record daily levels that can affect health.
Vancouver Edmonton Toronto Montreal Saint John Source: Environmental Signals National Environmental Indicator Series, Environment Canada (2003) http://www.ec.gc.ca/soer-ree
Hint: Check the number of milligrams of active ingredient contained in one prescribed medication. What is the difference between a milligram and a microgram? Concentrations of carbon dioxide, the most important of these greenhouse gases, appear to have never exceeded 300 ppm during at least the last 400,000 years. During the past century, concentrations of global carbon dioxide have increased by 31%. Other gases have also increased dramatically. See the graphs below for global methane, nitrous oxides and sulphur dioxide. There is clear evidence that these increases are due to human emissions, mostly from the burning of fossil fuels for energy purposes and from land use changes. .
Smog has become a common term for urban air pollution. It contains two key elements: fine airborne particles and ground-level ozone. The Canada-wide graph below shows levels of each named pollutant as a percentage of maximum acceptable levels. Ozone is also explored further later in this section.
Other greenhouse gases also affect the climate. Concentrations of nitrogen oxides and methane as well as sulphate aerosols have risen dramatically. Because of the volume of emissions, human emissions of CO2 remain the most important cause for human induced climate change, followed by those for methane, halocarbons, and nitrous oxide. The following 3 graphs for concentrations of these important contributors to climate change. Note that the graphs cover different time periods and use different units of measurement of concentration.
Concentrations of methane have increased by more than 150% relative to pre-industrial concentrations. That for nitrous oxide has risen by 16%. Both are now unprecedented in the 400,000 year ice core record. As with CO2, these increases appear to be linked to human activities. Greenland ice cores indicate that concentrations of sulphate aerosols in the Northern Hemisphere (a global cooling factor) increased rapidly during the 20th century but have somewhat declined since the early 1980s. The recent decline appears to be directly related to North American and European efforts to reduce human emissions to mitigate the risks of acid precipitation and other related environmental concerns. Source: Adapted from IPCC 2001. Climate Change 2001: The Scientific Basis Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change [Houghton,J.T. et al. (eds.)]. Cambridge University Press, Cambridge, UK. pg 36. OZONE(O3): Must be considered as stratospheric ozone as well as ground-level ozone. Although the same molecule O3, it participates in reactions with different molecules in these two different locations- kilometers apart in our atmosphere. Thus scientists who specialize in air quality for human health- study ground level ozone and different chemical reactions than the scientists who specialize in ozone in stratospheric chemistry. The following article helps to make this connection but deals with stratospheric ozone.
Source: Solar UV in our World (2002) ACER, Environment Canada, Health Canada www.acer-acre.org The graph below shows ozone concentrations for 35 years for both north and south hemispheres.
Source: H. Hengeveld et al., (2002) Science and Impacts of Climate Change CD Presentation Graphics MSC Environment Canada/ ESS Natural Resources Canada, December
Solar UV in our World (2002) ACER, Environment Canada, Health Canada www.acer-acre.org Research: What has been happening in ozone layer over the Canadian Arctic and north pole in the last 5 years? Hint: Check out the diagram below. O2 = oxygen molecule, O3 = ozone molecule Cl = Chlorine atom
Solar UV in our World (2002) ACER, Environment Canada, Health Canada www.acer-acre.org
The map below shows the number of hours with ground level ozone over 82 parts per billion(ppb). More than 4 hours in air with ground level ozone >82ppb can cause permanent lung damage in adults.
Source: Environment Canada
Diseases A warmer climate and longer frost-free seasons may permit the spread of new diseases from warmer climates, such as Lyme's disease, malaria, and West Nile virus. Local environmental and economic conditions and public health infrastructure are the key factors influencing actual occurrence of disease. In the last few years, several new diseases appeared in Ontario for the first time such as SARS, Lyme's Disease, West Nile virus. Managing community health for changing risk factors is vital. Announcements concerning West Nile virus, for example were delivered many different ways - from TV spots, interviews with local health authorities, enclosures with household mailings in several languages. All information recommended avoidance of dawn and dusk hours outside and proper application of repellant. Some communities chose to put repellant pellets in catch basins etc.
The diagram below tries to tie it all together! The natural workings of our atmosphere and the effects of human activities on it as well as the effects of changes in our atmosphere on humans!
Source: Solar UV in our World, ACER, Environment Canada, Health Canada,2002 www.acer-acre.org ACTIVITY 16 Review the diagram carefully.
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Climate
Change and Human Health 
The
number of hospital admissions due to asthma also show a relationship
to weather, especially in relationship to smog levels. The affect of
temperature changes on health should be examined in the context of changes
in CO2 concentrations and smog conditions. 
