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Winter smog

Aerial photo with industry and smoke
Smog is a contraction of the words smoke and fog. Smog used to mean a combination of fog and air pollution. The RMI defines smog as a period of increased air pollution. Fog is not necessarily present.

In the winter months, smog occurs mainly when there is an excess of particulate matter and sulphur dioxide. This is called winter smog. This pollution can have various health effects, such as respiratory problems.


Your behaviour:

  • Opt for greener mobility: public transport, cycling, walking, carpooling.
    • Do not use your car for short distances.
    • Try to consume less fuel by driving in a less sporty way.
    • Maintain your car well.
  • Insulate your home properly.

Your health:

  • Check with your doctor to find out if a peak in pollution levels will impact your health.
  • Consult the website http://www.irceline.be/ for the current air quality situation.


Your behaviour:

  • Do not run the engine when stationary.
  • Preferably use public transport.
  • Turn down your heating.
  • Avoid the most polluting forms of heating, such as a fireplace.

Your health:

  • Inform yourself and follow the recommendations of the government.
  • Limit your outdoor activities. This applies in particular to:
    • Elderly people
    • People with heart or lung problems
    • Babies and children
  • Consult your doctor if you experience unusual breathing problems.
  • Visit people in your surroundings who you know may be experiencing problems due to a peak in pollution levels.


  • There are no specific recommendations.

Impact and probability


Large-scale deterioration of air quality. Impact: low impact. Probability: very likely.Extreme weather events occur several times each year and are expected to become even more extreme and more frequent in the future due to the influence of climate change.

In 2018, the National Crisis Center coordinated a large-scale risk assessment for Belgium for the period 2018-2023. Several experts assessed various risks based on their probability and their impact on people, society, the environment and the economy.

For the risk of 'large-scale deterioration of air quality', the analysis is:

  • Impact: low impact
  • Probability: very likely

Read more about this analysis and what this chart means here. 

What do the authorities do?

The Belgian Interregional Environment Agency (IRCEL-CELINE) monitors air pollution in Belgium. IRCEL sends out alerts when smog thresholds are exceeded. There are several thresholds:

  • Information threshold: The population receives information and tips to protect themselves or limit air pollution.
  • Alert threshold: Measures will be taken to reduce emissions.

Each regional authority takes possible measures in case of an information or alert phase, for example a ban on burning wood or a speed limit of 90 km/h. If necessary, mayors can announce additional measures in municipalities with extra high concentrations.