Raising awareness for action
Individuals’ perceptions of air quality and environmental issues widely vary.
How do we think about air quality?
If you ask a sample of citizens how they perceive the quality of the air around them, the vast majority will talk about odour and pollution. That’s the general perception…
Yet air quality monitoring is a truly scientific discipline, which aims to determine the pollutants in the air and their concentration levels in order to identify health risks and prevent the associated health problems.
According to studies by Santé Publique France, 46,000 premature deaths a year are due to poor air quality, 40,000 of which are attributed to fine particle pollution, particularly PM2.5, which causes severe lung and heart problems. The most vulnerable groups are children, whose health can be affected in the long term.
The various players involved in air quality ...
Two directions can be used to define an image of the players involved in air quality:
– a sensory axis reflecting the feeling of air quality either through ‘Measurement’ or simply through ‘Perception’.
– a categorical axis reflecting, on the one hand, the ‘Scientific’ community and, on the other, the non-specialist ‘Citizen’ community.
These axes define three main areas where we find players with different aims:
– the ‘Experts’, who include air quality research and study organisations as well as monitoring bodies such as Atmo, which is represented in each French region.
– the ‘Committed’, without being technical specialists, are at the service of citizens to guarantee better air quality by referring to technical data and scientific recommendations. They include local or regional authorities, in particular decision-makers responsible for ensuring the well-being of citizens, as well as associations working to improve understanding of air quality.
– the ‘Motivated’, who are concerned about air quality and involved in environmental associations or simply take part in information meetings or debates.
A special, but essential, group of people working with groups of citizens (associations, schools, etc.) providing educational support, like educators, on the perception of air quality with a view to raising awareness and encouraging people to take action to improve our environment.
Air quality indices and standards
There are several indices reflecting air quality and provided on different websites:
- the IQA US index, which is a calculation that takes PM2.5, PM10 and NO2 concentrations into account; it allows you to compare the air quality of different cities around the world. The iqair.com website provides live readings from the sensors listed on an interactive map; it includes official Atmo sensors and other (unidentified – such as citizen sensors) sensors.
The Atmo France index as defined on the Atmo-bfc.org website based on a colour scale presented below (source Atmo) according to the new 2020 rules:
This index is presented as a daily index and does not exactly follow the colour code used by Atmo Occitane, which is reflected in the diagram presented on the home page. The Atmo Occitanie index appears to be an annual index and is used in the graphs presented on this same page on a monthly basis.
- The WHO index: The WHO does not really have a graded air quality index, but it does issue recommendations on how concentrations should be maintained over the year, as well as a tolerance value for daily exceedances.
a) The tolerance value for exceedance applies to the 99th percentile of values recorded. The tolerance of exceedance is allowed on 3 to 4 days per year.
There are also other indices applied by dedicated entities (e.g. Cellule Interrégionale de l’Environnement – Belgium) with different valuations to those above.
The aqicn.org site (Chinese site) provides a list of all the sensors identified in the world, including in particular the Sensor Community’s citizen sensors with an air quality index but mainly raw measurement values without processing.
What we learn from air quality
The Atmo Occitanie website (atmo-occitanie.org) provides good summaries of the state of air quality throughout the region. However, the overall summaries are not provided until well after the year in question. It would appear that, in terms of pollutants, fine particles represent only a fraction of the pollution, with other compounds such as nitrogen oxides (NOx) and ozone being just as worrying.
The images opposite from Atmo Occitanie give an overall view of the environment in Toulouse for the year 2022 for concentrations of fine particles (similar images for PM10 and PM2.5). It can be seen that roads are the main places where permitted concentrations are exceeded. This is also the trend shown by the analysis results presented on this site. However, a global analysis averaged over one year overwrites local and temporal trends.
One might therefore think that all is well and that we can be satisfied with a situation that is not so critical….
The advantage of multiplying the number of measurement points and monitoring them is to identify criticalities and their evolution and occurrence in relation to specific events. Hence the additional advantage of a citizens’ network driven by the desire to know and understand, so that we can alert and act secondarily.
In Castanet Tolosan, the D813 main road is just as critical as Toulouse’s main arteries. The average measurements presented confirm this observation for the month in question; apart from this main route, questions may also be asked about the town’s secondary roads, which are also very busy but currently have insufficient measurement points (dotted lines). The measurements also show concentrations that are not correlated with road traffic, but may be the result of heating emissions, in particular wood-burning, which is common in residential areas.
Causes of fine particle pollution
Analyses carried out by specialist laboratories on particles emitted in urban areas show that the majority of the chemical species making up fine particles are carbon-based (60 to 70%) (organic and black carbon), i.e. they come from fossil fuel and biomass combustion sources. The two main emitters of these compounds are road traffic and heating. This information makes it possible to envisage actions to be taken to reduce the concentrations of these compounds in the air.
Pollution from motor vehicles
Pollution tests on vehicles show that they differ according to whether they are petrol or diesel-powered and how old they are. For a long time, diesel vehicles were highly polluting, but their emissions have fallen considerably in recent years as a result of various vehicle standards and the introduction of effective particle filters. Today, diesel vehicles emit no more fine particles than petrol vehicles; recent IFPEN tests show a trend in favour of diesel vehicles.
However, in terms of NOx emissions, which are highly polluting but not presented on this site, diesel vehicles are more polluting than petrol vehicles. Their emissions depend on the conditions in which the vehicles are used and the climatic conditions; short journeys and the use of cold engines generate very high emissions, which have a detrimental effect. No equivalent data is available for fine particle emissions.
However, according to a study by Adème, more than half of the fine particles emitted by recent vehicles do not come from the exhaust of combustion gases. Emissions due to wear and tear on tyres and braking systems are becoming predominant.
Since 15% to 20% of the French car fleet is made up of recent vehicles, emissions from vehicle combustion gases continue to make a significant contribution to the concentration of fine particles in urban areas.
Pollution from heating
Wood heating appears to be a major source of fine particle emissions, particularly PM2.5. According to a study by researchers at the Paul Scherrer Institute (Switzerland), the oxidising potential of the particles produced by biomass combustion is even more toxic than the particles produced by the exhaust gases from old diesel and petrol vehicles. Wood combustion is also a major source of polycyclic aromatic hydrocarbons (PAHs) and carcinogenic gases. Wood emits up to 35 times more PAHs than fuel oil.
So what are the levers for action?
We need to distinguish between methods of action through the implementation of new regulations, incentives from local or national authorities and the mobilisation of citizens through awareness-raising to take action.
Regulations
For several years now, the governing authorities at national and European level have been aware of the impact of air quality on public health, and have defined new regulations. This is particularly the case with regard to vehicle traffic in urban areas, with the introduction of ZFEs (Low Emission Zones) in conurbations with more than 150,000 inhabitants, introducing traffic restrictions for the most polluting vehicles.
However, such restrictions cannot be applied in smaller conurbations, and the necessary improvements require the mobilisation of the public and an appropriate awareness-raising approach.
Incentives
In addition to regulations that are sometimes difficult to apply, mainly financial incentives are being deployed to curb the sources of particle generation:
- deployment of electric vehicles for road and mainly urban transport (small cars)
- development of soft mobility: walking, use of cycles, creation of pedestrian zones and cycle paths
- development of car-sharing
- facilitating public transport (trains, buses, metro, etc.).
Incentives are not limited to modes of transport, and improving wood-burning has become a major health concern:
- improving the fireplaces used (restricting use, or even replacing old, open hearth appliances).
Citizen mobilisation
Since air quality is a key public health issue for every citizen, significant improvements cannot be achieved without public involvement. Specific actions are therefore being implemented as part of the Health-Environment plan drawn up by local authorities and the Regional Health Agencies (ARS). One example is the ACT’R mobilisation plan run by the WaltR company in the Toulouse region, in which anyone can take part.
Working with local players
Raising public awareness and mobilising local players, associations, local authorities, citizens’ groups and the educational world, bringing together a varied public and involving young people, who are the most vulnerable to the hazards of air quality, is essential in the drive to improve our environment.
Creativity in proposing solutions is both necessary and a source of motivation.