Download 11.2 The Atmosphere and Pollution

SCH3U
The Atmosphere and Pollution
Some of the gases in our atmosphere will trap the sun’s radiant energy
- these gases are referred to as greenhouse gases (GHG). While some
of the sun’s energy is reflected back into space, certain gases and
vapours have the ability to absorb this energy, thus, keeping the
thermal energy in the atmosphere. The gases mainly responsible for
this is effect are carbon dioxide, methane and water vapour. (see fig.
4 p. 522) The increase in concentration of these gases are believed to
influence our global temperatures.
Other atmospheric concerns have to do with our air quality. If there
are no restrictions on industrial pollution, photochemical smog will be
the reality in many of our urban areas. Smog is a mixture of ground
level pollutants including fine particles, ozone (O3), sulphur and nitrogen
oxides. Other outdoor pollutants that reduce air quality are carbon
monoxide (CO) and volatile organic compounds (VOCs) like aerosol
propellants or cleaning solvents.
One of the ways you can judge how healthy the outdoor air is to
breathe is to consult the Air Quality Health Index (AQHI) at:
www.ec.gc.ca/cas-aqhi of Environment Canada. The scale gives air a
rating of 1-10 (1 being low risk and 10 being high risk).
Indoor Air Quality can also be problematic. VOCs from a variety of
sources can cause pollutant concentrations to increase. Formaldehyde
(also known as methanal, a common preservative and suspected
carcinogen) is found in many of our wood based products, paints and
fabrics. Incomplete combustion of fossil fuels (natural gas, propane
burners, etc.) can cause CO gas concentrations to increase which is a
poison and cause a variety of health problems including death.
In our basements, there is a concern of radon gas that could enter our
house through cracks in the wall. Radon is the last naturally occurring
noble gas and is radioactive. This could lead to cancer with prolonged
exposure. There are also a number of biological pollutants that exist in
your home. These include bacteria, viruses, moulds and a host of
airborne particles.