Raising awareness in air quality to better behave in our environment
Air, like water, is common to all living things – human, animal and plant – and is the source of all species’ development and survival.
A site for sharing information on air quality between citizens
Air quality is affected by a number of components, including fine particles that affect the respiratory tract and irritating gaseous compounds.
When air quality deteriorates sharply, it can sometimes be smelt, but more rarely seen. Only measurements can describe the state of the air, enabling citizens to be reassured or alerted so that they can adapt their lifestyles.
Measurement of fine particles 24h/24h
Thanks to sensors installed by responsible citizens.
Citizen network
Data recovery via a network linking all the players.
Operation and distribution
The data is processed and the results disseminated thanks to committed citizens.
An ecological and scientific approach to citizenship
Citizens are becoming increasingly aware of the importance of air quality, especially in large conurbations. The Covid 19 crisis has heightened this perception, prompting individuals to take a better look at their environment.
Today, sensors for measuring air quality, mainly fine particles and CO2, are available on the market or from associations.
This site presents what citizens can gather from their sensors when their data is pooled.
An initiative in Toulouse (France)
The city of Toulouse and its suburbs boast a concentration of measurement sensors, providing a global view of air quality in the region.
This specificity, combined with a desire to gain a better understanding of the measurements acquired, led to the creation of this site, which focuses primarily on the environment of the Toulouse region.
Three cities in France are equipped with citizen sensors, enabling us to carry out an appropriate analysis: Paris, Toulouse and Rennes. In addition to Toulouse, the site also focuses on the other two cities of interest.
An extended investigation
Rennes is also specific in having a community of citizens mobilized to monitor their environment through a local association. In harmony with the analysis approach implemented for Toulouse, the measurement results for the Rennes conurbation are presented here over a limited period (June 2024):
Paris is the area with the highest concentration of air quality monitoring sensors in France, both official and citizen sensors. It is also one of the cities most affected by deteriorating air quality.
Analysis of the data available from both official and citizen sensors is highly interesting and instructive for citizens in understanding their environment and encouraging them to do their own monitoring.
Environmental monitoring in the Toulouse region
(Haute-Garonne - France)
The citizens’ group is based in Castanet-Tolasan, a commune on the outskirts of Toulouse (south-west France) and is interested in the overall environment of the Toulouse region.
It is based on a local network of low-cost sensors set up by various local residents. These sensors are dedicated to measuring the concentration of fine particles (PM10 and PM2.5, i.e. particles around 10 microns and 2.5 microns in size). The data is centralised within an international community called the ‘Sensor Community’ and made public on the community’s website.
Environment in Toulouse
The quality of the environment averaged over the period under consideration is acceptable in the city of Toulouse and the Toulouse suburbs. The differences between the urban centre of Toulouse and the suburbs are the result of significant pollution in the centre of the large conurbation, probably due to road traffic. The detailed readings presented below show a homogeneous period over the month.
The average values presented take into account the measurements of the citizen sensors and those of the official Atmo Occitanie sensors.
Translated with DeepL.com (free version)
The colour scale opposite is the classic transcription of concentration values in terms of air quality. This interpretation is less severe than the consideration of the new WHO standards as taken into account in the analyses of the various measurement curves presented in the corresponding tab.
Air quality indicators
Air quality index values for zones monitored over the month of :
August 2024
PM 10
Toulouse inside the ring road
Acceptable
Toulouse Suburb
Good
Castanet-Tolosan
Good
PM 2.5
Toulouse inside the ring road
Medium
Toulouse Suburd
Acceptable
Castanet-Tolosan
Good
Variations in local measurements
Despite acceptable average values, there are variations between the various measurement points in neighbouring districts or municipalities.
Detailed environment of the Toulouse region
- Average PM 10 measurements (readings in microgrammes / m3)
The average PM10 values recorded show a high trend over the month, with a general increase across the whole of the Toulouse region and its suburbs. However, the measurements taken on the Toulouse ring road by the official sensors (in blue circles) are at an acceptable level. The maximum value of 22 at Rangueil (compared with 26 in July) indicates a moderate trend. This suggests that the increase is not mainly due to road traffic. As the detailed curves below show, the deterioration is most marked in the second half of August.
The measurement points near the airport (Blagnac) show stability over the month compared with July.
The point located in the extreme north-east (value 12 in PM10) corresponds to the location of the second incubator in Toulouse; the first incinerator is located to the north-west (FR500039) indicating an average concentration of 14.
The northern and eastern parts of Toulouse, where there are no sensors, cannot be properly assessed.
Dedicated values in Toulouse
- Average PM 10 measurements
Special focus on Castanet-Tolosan
- Average PM 10 measurements
- Average PM 2.5 measurements (readings in micrograms / m3)
Citizen sensors can assess PM10 and PM2.5 concentrations at the same time, which is not the case for all official sensors. There has been a marked increase in average values compared with last July.
Toulouse southern ring road at Rangueil
- Average PM 2.5 measurements
- Average PM 2.5 measurements
Dynamic visualisation of particle concentrations
Much more than a map of local averages, the dynamic display shows particle concentrations in all locations at all times. This representation is an interesting way of assessing the criticality of a given location in relation to the overall environment of an area.
PM10 concentration trends in the Toulouse region
Visualisation
PM10 and PM2.5 in Toulouse
The two videos opposite show the environment considered over the period August 1 to August 31 2024. The accelerated speed corresponds to approximately 4 hours every second.
All valid measurement points (Atmo Occitanie sensors in Toulouse and citizen sensors) are taken into account in these simulations.
PM2.5 concentration trends in the Castanet Tolosan area
Decryption
Temperatures in August remained higher than normal for the month (see general trend in the “Monthly results” tab). Temperatures were relatively uniform throughout the monitored area.
The detailed PM10 and PM2.5 curves below show an initial period that was relatively homogeneous and stable over the first 18 days of the month, followed by a more disturbed period over the following days. This second period is the cause of a significant increase in the average concentration values over the month compared with the values for previous months.
While the average PM10 trend remains acceptable in terms of the WHO standard (15 microgrammes per m3), with a few critical values above the acceptable threshold (45), the average PM2.5 value is well above the recommended WHO threshold (5), with maximum values often well above the tolerated cumulative daily threshold (over 5 to 6 cumulative days per year).
The concentration of fine particles PM2.5 was therefore critical in August in the Toulouse region.
Translated with DeepL.com (free version)
