Section 11.4: Air Quality
Research This: The National Commuter Challenge, page 531
Answers may vary. Sample answers:
I chose the the National Commuter Challenge:
A. Who: All working Canadians.
What: To participate in the challenge, you must walk, cycle, carpool, take transit, or
telecommute at least once during the Commuter Challenge week.
When: During Canadian Environment Week, which is usually the first week of June.
Where: All across Canada.
How: Register online before the Commuter Challenge week, participate, and then log your
sustainable commutes during the Commuter Challenge week and view the results from cities
across Canada.
B. Sustainable Transport Benefits
Health and Personal
-Increased exercise with walking/cycling to work can have significant health benefits.
-Carpooling can help develop new friendships.
-Less wear and tear on your own vehicle.
-Use the commuting time for reading, working, or relaxing.
-Public transportation in Canada is considered a safe way to travel.
Environmental
-Less greenhouse gases (GHG) are released into the environment.
-Fewer cars on the road will improve air quality.
-Less vehicles on the road will reduce traffic and road maintenance.
-Public transport reduces urban sprawl.
-Less cars on the road will mean less traffic noise.
Economic
-Reduced spending on fuel.
-Reduced insurance costs for individuals.
-Reduced use of roadways will mean that less money is spent on road repair.
C. The National Commuter Challenge has seen a great increase in participation, both in
individuals and cities, over the years since it began in Calgary in 1991. It was developed as a
national program in 1999. As of 2009, the event has grown to include over 1 600 companies,
44 000 commuters, and over 40 cities across Canada. There has also been a significant increase
in the number and quality of activities that surround the National Commuter Challenge.
Participating cities have developed special programs to promote participation within their
specific areas.
In 2010, the highest ranking cities were Winnipeg, Waterloo, and Ottawa. There is no
information on the cities with the lowest participation rates or rankings.
D. Yes, the program can be considered a success. The program encourages people to try
commuting in a more sustainable way. Some of these people may discover that the new way of
commuting is a good alternative to driving. The program also creates awareness about pollution
and GHG emissions by having people consider the impact their daily commute has on the
environment. The program also has a positive influence on people’s health in encouraging them
to walk or ride their bikes to work. I do not think it helps improve air quality in the short-term,
but it may improve air quality in the long-term if it influences Canadians’ commuting habits.
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Chapter 11: The Gas State and Gas Laws 11.4-1
E. Yes, the initiative is running where I live. My family and I could participate by using public
transit instead of our vehicles during Commuter Challenge week.
F. The main thing that prevents me and my family from using public transportation is
convenience. My family has a car and so it is more convenient to drive to where we want to go
rather than rely on the public transit schedules.
Section 11.4 Questions, page 533
1. (a) Photochemical smog is a hazy cloud of air pollutants formed by the reaction of emissions
from factories and vehicles with sunlight.
(b) Many of the reactions involved in the production of photochemical smog require sunlight.
Since there is more sunlight in the summer, there is more smog produced in general during the
summer months. Some smog is possible in winter months.
2. (a) The two greatest sources of particulate matter emissions in Ontario are transportation and
residential sources, such as home furnaces or woodstoves.
(b) Some ways that Canadian households can reduce their particulate matter emissions are:
keeping vehicles well maintained, ensuring that furnaces, barbeques, or any other fuel burning
equipment are clean and well maintained, keeping homes clean, and reducing the amount of dust
and particles released from sources like building materials.
(c) Particulate matter can cause damage to the respiratory system, especially in those individuals
who already have respiratory difficulties.
3. Two gaseous air pollutants are sulfur dioxide, SO2, and nitrogen, dioxide, NO2. The main
sources of emissions are smelters and utility plants.
4. Carbon monoxide can be released by vehicles through the incomplete combustion of gasoline.
If there is a traffic jam there are many cars in a localized area releasing carbon monoxide. This
can cause the concentrations of carbon monoxide in the traffic jam to be higher compared to
normal levels.
5. (a) VOCs are volatile organic compounds.
(b) Examples of consumer products that release VOCs are gasoline, cleaning solvents, paints,
and wood products used in construction.
(c) When working with products that emit VOCs the manufacturer’s instructions should always
be followed. For example: use in a well-ventilated area; do not use in enclosed spaces.
6. (a) High wind may disperse particulate matter and other gases that form smog. High winds
may also disperse nitrogen oxides and minimize the amount of ozone formed in a specific region.
(b) Increased cloud cover may result in decreased smog and ozone. Both of these pollutants
require UV radiation to form, and with increased cloud cover, less UV radiation will reach
Earth’s surface. This will reduce the amount of smog and ozone formed.
(c) Increased sunlight may produce more ozone and smog. Summer, having more direct sunlight
than other seasons, will generally have greater amounts of ozone and smog. Smog and ozone can
occur in the winter months but generally concentrations of these pollutants are less.
(d) During a public holiday there are fewer commuters. This will produce less nitrogen oxides
and result in less ozone. Fewer commuters will also produce less particulate matter and entities
that produce smog. If factories are also closed for the holiday, fewer pollutants will be released.
This will further reduce the amount of smog.
7. (a) AQHI stands for air quality health index.
(b) The AQHI scale is intended to help Canadians assess the health effects resulting from air
pollution.
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Chapter 11: The Gas State and Gas Laws 11.4-2
(c) The AQHI scale is useful to all of the population but in particular to those people who are
considered at-risk. The at-risk population includes people with existing cardiovascular or
respiratory problems, those who are very active outdoors, the elderly, and the very young.
8. (a) For O3, the maximum concentration is reached at noon, while the minimum concentration
is reached at midnight.
For NO2, the maximum concentration is reached at midnight, while the minimum concentration
is reached at noon.
(b) Ozone can be produced by a series of reactions involving nitrogen oxides and UV radiation.
Nitrogen oxides are released in high levels during the morning and the evening commute. The
nitrogen oxides released during the morning commute react in the presence of UV light which
results in a maximum ozone concentration at noon. The nitrogen oxides released during the
evening commute have less sunlight available to react with to form ozone, so the nitrogen
dioxide remains into the evening. This produces a maximum nitrogen dioxide concentration at
midnight.
9. Answers may vary. Students’ answers should include air pollutants from one country or region
which can be carried into other locations. For example, about half of the fine particulate matter in
Ontario originates in the United States. Countries and/or regions must act together to combat air
pollution.
10. When we burn fossil fuels particulate matter and a variety of gaseous pollutants are released.
The gaseous pollutants (like nitrogen oxides and sulfur oxides) lead to increased levels of ground
ozone, acid precipitation, and increased levels of greenhouse gases. The increased levels of
greenhouse gases are linked to increasing global temperatures. However, the particulate matter
released causes thermal energy to be reflected back into space, which reduces global
temperatures—this is known as global dimming. Global dimming may be masking the effects of
increased levels of greenhouse gases. The increased levels of particulate matter can also have a
cooling effect on regions far removed from where the particulates are generated. Global dimming
may change precipitation and wind patterns that could have devastating effects.
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Chapter 11: The Gas State and Gas Laws 11.4-3