The sale of anti-pollution masks is quite seasonal, I have noticed this for 8 years. The market takes off in October and declines in April. It obviously cannot only be about protection against the cold, even if a mask is very useful for that. So I was interested in the reasons for the greater frequency and intensity of pollution peaks in winter. Let's see why are there more pollution peaks in winter?
Does weather impacts pollution peaks?
Statistics show that there are more pollution peaks in winter than in summer and that their intensity is higher, meaning that alert thresholds are more regularly exceeded. How can this be explained?
As a general rule, the further away from the ground you are, the lower the air temperature becomes. However, in winter, the opposite can happen. When it is cold, the air in the upper layers of the atmosphere can be warmer than the air on the ground. This is called a thermal inversion . The cold air remains stuck to the ground by the warmer air at altitude, like a lid, which prevents pollutants from dispersing. In winter, this situation is even more marked by the temperature difference between nights and days. Cooled at night, the air does not have time to warm up during the day, and therefore remains stuck to the ground. The absence of rain or wind can aggravate this phenomenon. The rain pushes the fine particles to the ground and the wind disperses them.
Is residential heating impacting pollution?
Residential heating creates a huge amount of fine particles, CO2, nitrogen monoxide and dioxide, sulfur and dioxins that contribute to global warming. Since its use is more intense in winter, it is obvious that it contributes to winter pollution peaks.
What are the least polluting heating methods?
Oil heating is by far the most polluting. It is for this reason that the installation of boilers or hot water production running on oil has been prohibited in France since July 1, 2022, except in cases where it is impossible to use other energy sources.
The combustion of natural gas mainly emits water vapor and carbon dioxide (CO2) in small quantities (30 to 50% less CO2 emissions than other fossil fuels).
Electrical equipment is the least polluting when in use, because it does not emit CO2 and does not release fine particles. The impact of electric heating on the environment is therefore very low… The same cannot be said for the production of electricity that powers the radiators, which is partly based on fossil fuels!
The CO2 emitted by burning wood is offset by the growing biomass through photosynthesis. The carbon dioxide released into the air during its combustion corresponds to that which was absorbed during the growth of the tree, unlike fossil fuels. Wood heating is therefore climate neutral, on the other hand it emits a lot of fine particles which makes it a very large contributor to winter pollution peaks.
Solar energy wins the prize for the most environmental friendly and least harmful heating for health. The urgent need is to develop it everywhere where it makes sense, that is to say in regions where the intensity of sunshine is sufficient.
What other factors aggravate winter pollution peaks?
Agricultural activity and the practice of spreading fertilizers emit ammonia into the air in February and March.
The relief plays a significant role and this explains why some mountain towns or valleys are so often drowned in winter pollution. Air masses can be slowed down, or even blocked, by the mountainous relief. A "bowl" topography or a valley enclosed between two massifs will considerably amplify the phenomenon of accumulation of pollutants in the atmosphere because their horizontal dispersion will be reduced.
Car traffic of course because people take less their bikes or motorbikes when it's cold or rainy. This is why during episodes of high pollution or when the alert level is exceeded, the public authorities seek to limit the main polluting activities. Speed is limited, traffic alternates depending plates numbers or accreditations, residential parking is free for vehicles as well as public transport.
Why is there less ozone pollution in winter?
Cold weather isn't the only thing that impacts pollution. Ozone, for example, is a secondary pollutant, meaning it's not emitted directly by human activities.
Ozone is actually the result of chemical transformations of primary pollutants (such as nitrogen oxides and volatile organic compounds) under the effect of solar radiation.
Therefore, this pollutant is particularly present in summer.
How to be notified of pollution peaks?
Even if the media generally communicate about it, many applications, all over the world, allow you to have real-time access to air quality. They give the alert a few hours before the appearance of a pollution peak. You will have every day, information on air quality, measurements from each station, alert thresholds and recommendations.
How to protect yourself effectively during a pollution peak?
Wearing an anti-pollution mask with FFP2 filters like the Frogmask masks remain a simple, practical, economical and very effective gesture to protect the respiratory tract from air pollution, especially for people riding on 2 wheels. In addition, they keep you warm in winter and their water-repellent material prevents you from having a wet face on rainy days.
