Air Quality: Smog

Smog

What is Smog?
The word "smog" was first used more than 30 years ago to describe a mixture of smoke and fog in the air. Nowadays, the term is used to describe a harmful combination of air pollutants that can typically be seen as a haze in the air.

Smog can hinder breathing, even for healthy people, and it can make a person more vulnerable to cardio-respiratory diseases. Smog has a particularly strong impact on people with lung disease, the elderly and small children.

It is the ozone and fine airborne particles in smog that have an impact on overall health.

Airborne Particles
Airborne particles are tiny in size and stay hanging in the air for long periods. These particles can be categorized as both primary pollutants and secondary pollutants, which are propelled into the atmosphere in the form of windblown dust and soil, sea salt spray, pollen and spores.

Secondary particles develop as a result of chemical reactions involving nitrogen oxides, sulfur dioxide VOCs and ammonia.

The particles that are present in smog are what give it colour and impact visibility. The air can take on a yellowish-brown or white colour depending on the type of particles present in the smog. It is believed that particles have a negative impact on vegetation and various synthetic and natural surfaces.

The areas in Canada where smog can be a serious problem are: