Allergy: “the amount of pollen in the air continues to increase”

Passionate about the environment and the weather, Samuel Monnier is an engineer in charge of communication and associations in the National Aerobiological Surveillance Network (RNSA).

Holder of a Master 2 Climate-Risk-Enviro

What are the origins of the RNSA?

Founded in 1996, the RNSA took over from Michel Thibaudon’s work at the Pasteur Institute’s Aerobiology Laboratory. Since 1985, this expert in biocontamination and allergy has been studying the biological particles in the air, and more specifically pollen and mold. From now on, with the help of public funding and voluntary service providers, the RNSA aims to inform the public about the risks of allergies and help those affected to adapt the treatment of their symptoms as well as their behavior. .

>> Read also: How to avoid pollen?

How vital is the work of the RNSA to the population?

First of all, you should know that between 20 and 30% of French people are allergic to pollen. However, the flowering of anemophilous plants, the seeds of which are carried by the wind, takes place throughout the year. And with them, the dispersion of the allergen into the atmosphere. With our surveillance cards, where allergy risks are rated from 0 (none) to 3 (high), the maximum number of people can anticipate their activities.

How do you get your data?

We have 80 sensors distributed throughout France, and more specifically on the roofs of hospitals or town halls of large cities, with which we have collaborations and where the population density is high. The devices are electric and operate by means of a pump that sucks in outside air through a small opening reminiscent of the human mouth. This mechanism allows you to simulate a person’s breathing, with approximately 10 liters of air absorbed every minute. The pollen contained in the atmosphere is then attached to the bands for later analysis.

“We have 80 sensors distributed throughout France, and more specifically on the roofs of hospitals or town halls in large cities. »

Because this is just the beginning of the process …

Indeed. For each sensor, there is a technical manager, an analyst and a physician in charge of the clinic. Once a week, the analyst collects the strips and extracts information about the concentration of pollen in the air.

After a protocol lasting about 2 hours, however, all the data is sent to the RNSA coordination center based in Brussieu, in the mountains of Lyon, in order to draw up surveillance maps. To do this, we combine these elements with weather reports, field observations by volunteers at a dozen botanical gardens, and sentinel doctor forms that report symptoms observed in current patients.


“My life as an allergy sufferer”

Personalized follow-up, treatment reminders, medical appointments, pollen alerts … This application helps you in the daily follow-up of your respiratory allergy.

“Pollen Alerts”

After geolocation, the app shows a score of 10 indicating the level of pollen in the air each day.

It also allows you to consult the alerts and advice of the RNSA.


Developed by allergists, this tool allows you to take care of your rhinitis. Once the data has been entered, it is possible to send it to a healthcare professional.


Customizable, the service includes a pollen diary that is used to calculate the level of personal exposure. A new feature shows hourly forecasts for the whole day.

Interview: 44 -

What do volunteers and time tell you?

Volunteers give us information about the flowering periods of the plants, whether in the parks or in the woods. In terms of climate, it plays a crucial role in pollen dispersal. In sunny and windy weather, pollen grains rise easily into the air and can travel long distances. On the contrary, in case of rain, they are flattened on the ground and, therefore, are less problematic for allergy sufferers. Only once all the data is associated with our surveillance maps can we transmit the information to the general public.

>> Read also: Why does pollen make you so allergic?

How do you submit your newsletters?

We take care of sending our results to the populations, who then transmit them to their fellow citizens, using light panels, for example. Interested people also regularly visit our website (, which received about 1.2 million visitors in 2021. It is also possible to subscribe through the site to our weekly newsletter, which has about 80,000 subscribers, and download smartphone apps. Don’t forget to follow us on social media (Twitter, Facebook, LinkedIn and Instagram).

Interview: 44 -


“In sunny, windy weather, pollen grains rise easily into the air and can travel long distances. On the contrary, in the event of rain, they are flattened on the ground.”

Which species do you control in particular and which regions are at risk?

We mainly monitor the flowering of cypresses, birches, herbs and ragweeds, which have a strong allergic power and affect many people, but we also monitor other species that can bother allergy sufferers. In total, this represents about twenty species for which we give the risk of allergy throughout the year on our website.

While cypresses are found mainly on the shores of the Mediterranean, birches populate the northern part of France and herbs are found everywhere. Ambrosia is firmly established in the Rhone Valley, but has also spread to New Aquitaine, Burgundy-Franche-Comté and Occitania.

We’re talking mostly about pollen, but what about mold measures? Also, what are they?

The most allergenic molds are Alternaria i Cladosporium. Its growth requires moisture and heat, the most risky months are still July and August. The sensors are identical to those of pollen, but due to the lack of analysts in this field, we only have a dozen today. However, the Ministry of Solidarity and Health has explicitly asked us to improve monitoring. Therefore, progress should be made in the coming years.

Finally, is there any phenomenon you are following especially right now?

In fact, it has been visible in the data since the 1980s, but we are still watching. According to our sensors, the amount of pollen in the air is constantly increasing. The curve is flat, although there are occasional slight falls, such as from 2019 to 2020, due to weather conditions. That is why members of the RNSA are campaigning for the non-planting of highly pollen-inducing species such as cypress and birch in cities. However, it is easy to do without them, favoring equivalent and less allergenic species.

>> Read also: Can allergies be cured?

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