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Where does smog come from?

Smog is a mixture of atmospheric pollutants. It often appears as a yellowish haze that reduces visibility.

These pollutants originate mainly from emissions from vehicles, motor vehicles, manufacturing and wood heating. Smog can form at any time of the year. In summer, it is mostly made up of ozone and fine particulates. In winter, it is mostly composed of fine particulates.

A period of smog can last anywhere from a few hours to a week. Its intensity depends on certain weather conditions (sun, temperature and wind), time of day, season and relative distance from the pollutants. To better clarify what smog is, it should be pointed out that it can occur when there is heavy traffic, it is sunny and there is low air circulation and low cloud cover. Smog can occur in urban and rural areas alike.

Situation in Outaouais

In Outaouais, transportation is the main source of atmospheric pollution and is the biggest contributor of smog, especially due to the heavy traffic between Ottawa and Gatineau.

What are the health risks?

Air pollution is associated with several, harmful health effects. The effects of pollution on health are determined by the duration of the exposure, the concentration of the pollutants as well as the health situation of the people exposed. The main effects of air pollution are associated mostly with pulmonary problems and cardiovascular diseases.

The main short-term effects are:

• Wheezing;
• Irritation of the respiratory tract;
• Difficulty breathing; and
• Tightness in the chest.

Furthermore, several recent studies show that long-term exposure affects pulmonary capacity and the cardiovascular system.

Ozone, one of the compounds in smog, is a very powerful oxidant. It is a major irritant of the upper respiratory tract (nose, throat and bronchi). Ozone is an aggravating factor in persons suffering from pulmonary and cardiovascular diseases. It can also affect people who are in good health. The main health repercussions of ozone over the long term are acute and chronic damage of the respiratory system. Even short-term exposure can cause acute myocardial infarction or arrhythmias that may cause premature death in people at risk.

What do you do in cases of smog?

In cases where there is a smog advisory, it is strongly recommended that people who are the most vulnerable, like young children, seniors and people suffering from respiratory or cardiac problems, avoid exerting themselves doing outdoor, physical activities, especially in areas where there is heavy traffic.

How can you help reduce smog in urban areas?

In order to reduce smog in urban areas, we encourage you to adopt ecofriendly actions, which are also good for your health, such as:

• Using public transit;
• Choosing active means of transportation, like walking and cycling; and
• Carpooling.

Current conditions and smog advisories

To find out the current air quality in Outaouais, please see the Air Quality Index Page Ouvre une nouvelle fenêtre. on the site for the Department of Sustainable Development, Environment and Parks.

To see smog advisories for Outaouais, visit the Info-Smog Ouvre une nouvelle fenêtre. site.

Useful links

Environnement Canada - Cote air santé Ouvre une nouvelle fenêtre. (pour Gatineau)

Pdf document. Ouvre une nouvelle fenêtre. Notre santé et notre environnement en Outaouais - Les véhicules et le smog 
PDF File: 145 KB | Available in French only