The two key components of smog are airborne particles and
Airborne Particles: These are
minute solid or liquid particles that are small enough to remain
suspended in the air. Particles give smog its color, which may be brown,
dark gray or white, depending on the type of particles. Small particles,
less than 10 micro- metres, have a significant effect on human health,
particularly for those who already suffer from heart or lung disease. Of
particular concern are the fine particles, less than 2.5 micrometres
that can penetrate deep within the lungs. Fine particles may remain
suspended in the air for days or even weeks and may be transported long
distances. The major environmental problem of airborne particles,
besides its health impact on humans, is reduced visibility.
Ground-Level Ozone: Unlike the
ozone that forms naturally in the stratosphere, ground-level ozone does
not provide any significant protection from the sun's harmful UV rays,
nor does it find its way to the upper atmosphere. Ozone is a colorless
and highly irritating gas that forms naturally when sunlight
"cooks" the soup of air pollutants often found over urban
areas on hot summer days. The precursor air pollutants, nitrogen oxides
(NOx) and volatile organic compounds (VOC), react with each other to
produce ground-level ozone.
Most Canadians in urban areas live where ground-level ozone may reach
unacceptable levels during the summer months. Periods of high ozone can
last several days and frequently occur when a stagnant air mass traps
pollutants over a region. Recent studies have shown that every major
Canadian urban centre has levels of ground-level ozone high enough to
pose a health risk.
Not only is ozone a problem for humans, it is also known to damage
vegetation and cause the deterioration of some natural and synthetic
materials, including paints and dyes. Ozone is also a powerful
greenhouse gas, which contributes to climate change.
Where does it come from?
On a national basis, 59 percent of (NOx) emissions and 27 percent of
VOC emissions come from the transportation sector. Other major sources
of the pollutants include the power generating sector and other
industrial activities. This means that individual Canadians are
responsible for generating the pollutants and, in turn, by making
lifestyle choices, can make a big contribution cleaning up the problem.
(photo: Environment Canada)
What you can do...
Many of the choices that we make every day have a direct impact on
the amount of pollution that goes into our air - from the way we get to
work in the morning to the way we heat and cool our homes. Since burning
fuel is a primary contributor to smog formation, reducing energy use and
making wise consumer decisions are important steps toward cleaner air.
Learn as much as possible about alternative energy sources, and discuss
your concerns about smog with other people-including your children. Join
a community group working for cleaner air. Following are some simple
tips to pass along.
Go public. Use public
transportation or car-pool instead of using your car; after all, one
bus-load of passengers saves nine tonnes of air pollution each year. If
smog levels are not too high, try walking or cycling.
Be fuel efficient. Make fuel
efficiency a prime factor in your choice of a new car. Pass up options,
such as air conditioning, that burn more gas; buy a smaller vehicle to
reduce pollution and travel costs; and consider alternative fuels such
as propane, natural gas and ethanol.
Stay tuned. Keeping your car
engine tuned and your tires properly inflated increases fuel efficiency.
Drive smart. Transport Canada
estimates that differences in driving style can lead to a 20 percent
variation in fuel consumption. Driving at moderate speeds and avoiding
quick starts and stops uses less fuel.
Turn it off. Idling your car
engine for even one minute uses more fuel than turning it off and
re-starting it. Most cars and trucks require only 15 to 30 seconds of
idling before being driven, even in winter.
Say good-bye to gas. Swap
gasoline-powered vehicles and machinery, such as motorboats, motorbikes
and gas lawnmowers, for human-powered versions like canoes and
sailboats, bicycles, and electric or push lawnmowers.