GTA Clean Air
Council
What is SMOG
Smog, the brownish-yellow hazy cloud caused
by the reaction between sunlight, heat and air
pollutants, is the most visible form of air
pollution. Although smog is a 
year-round
problem, the Ministry of the Environment issues
most smog advisories and alerts between May
and September. Smog affects large urban centres
as well as outlying suburbs and rural municipalities.
The two main ingredients of smog that affect human
health are ground level ozone and fine airborne
particles. The Environment
Canada Clean Air website contains useful information
on smog and its impact on human health.
GROUND LEVEL OZONE
Ground level ozone is harmful to humans, animals
and plants. It is formed when pollutants from gasoline
and diesel powered vehicles and oil-based solvents
react with heat and sunlight. Homeowners, industries
and power plants all contribute to ground level
ozone formation.
Ground Level Ozone can:
Inflame breathing passages
Cause eye and nose irritation
Interfere with the body’s ability to fight
infection and increase susceptibility to disease
Aggravate respiratory problems
Damage synthetic materials and textiles
FINE AIRBORNE PARTICLES
Fine airborne particles have a negative impact
on vegetation and many synthetic and natural surfaces.
Fine airborne particles give smog its colour and
affect visibility. These particles are a mixture
of liquid droplets and solid particles which come
from a variety of sources including dust, industrial
emissions and vehicle exhaust.
Fine airborne particles can:
Allow harmful chemicals to enter the lungs
Aggravate respiratory diseases
Increase the occurrence of disease and death
Cause obstructive airway diseases
NOTE: Links to sites external to the Municipality
of Clarington are provided as a convenience and
their inclusion does not imply that the Municipality
of Clarington endorses or accepts any responsibility
for the content or use of these sites.
