6 min. read

Breathe in, breathe out. How could a simple and indispensable routine become a major problem?

Air pollution is old, it has accompanied civilizations since humans created the first fires. Once local, it has now incrementally become a global challenge. When cities grow and get crowded, they must face significant air pollution issues and must organise themselves to contain them.

In Europe, public players monitor, communicate, set specific standards regarding pollution, and penalise those that do not adhere to them. Furthermore, some private companies offer effective and innovative ways to improve both urban and interior air quality. However, the economic and human toll is still massive and there is still much progress that can be made.

This White Paper gives an overview of the societal impact of air pollution and the diversity of the pollutants and their sources. As a global and complex challenge, the best solutions are not that easy  to find.  But it seems vital, just and profitable to make substantial efforts to improve air quality.

Impact of air pollution on societies

Air pollution slows down the economy. In 2015, the French senate has estimated that air pollution costs France 100 billion € each year[1]. On one hand, this includes the direct healthcare and absence costs of diseases and premature deaths associated with air pollution. On the other hand, there are losses of workforce productivity, agriculture yields, biodiversity and there is the degradation of structures.

From a medical perspective, air pollution increases the risk of cardiovascular and respiratory diseases. A study published in March 2019 in the European Heart Journal has estimated the annual excess mortality attributed to air pollution [2]. Worldwide, in 2015, the estimated excess death rate from air pollution is at 8.79 million[3]. As estimated by the World Health Organisation (WHO) at 7.2 million deaths per year, air pollution now kills more than tobacco smoking. While a smoker chooses to keep smoking, an individual is much less accountable for the poor quality of the air they breathe.

Figure 1: Estimated annual excess mortality attributed to air pollution


In the European Union, the estimated excess death rate from air pollution is 129 per 100 000. It is just over the worldwide rate of 120 per 100 000 even though EU applies one of the stricest controls of air quality. This can be partially explained by the high densities of population in the most polluted regions of Europe. Air pollution kills less in France, thanks to lower industrial and energy sector emissions but also because of favourable weather. Strong and consistent winds spread pollutants and renew the air in the polluted regions.

Understanding air pollution and its source

Air pollution is an atmospheric condition where chemical species are at high enough concentrations over their natural ambient level to induce measurable effects on humans, animals, vegetation or structure materials. Air pollutants are diverse, and each one requires special attention. The ones to monitor are listed by the EU, the WHO and the United States Environmental Protection Agency (USEPA).

In terms of the main ones, nitrogen oxides (NOx), particulate matter (PM10 & PM2.5) and Ozone (O3) are currently of major concern in France. O3 is a secondary pollutant, it is not emitted directly but rather formed through the photochemical reaction of primary pollutants, mainly volatile organic compounds (VOC) and NOx. Sulphur dioxide (SO2) is a major problem for societies relying heavily on fossil fuels, particularly coal. Petroleum refineries remove sulphur from raw petrol to create low SO2-emitting fuels. [4]

Technical glimpse on PM10 and PM2.5

PM10 include particulate matter of aerodynamic diameter below 10µm. PM2.5 is similar, but as they are below 2.5µm, they are harder to measure. Aerodynamic equivalent diameter has been defined to overcome the shape irregularities inherent to every particle. It is defined from the settling velocities of particles.

The human respiratory system possesses natural filters that prevent particles from penetrating deeper in the body. However, particles of size between 0.01µm and 2.5µm penetrate more quantitatively through these filters.

Therefore, PM2.5 are more dangerous, and that is why their monitoring has been implemented in addition to PM10. [9]

Some pollutants like heavy metals and carbon monoxide (CO) used to be of major concern but are now smaller issues thanks to appropriate regulation. However, it is still essential to monitor them because they might become an issue again. For instance, after the fire of Notre Dame in Paris, high concentrations of lead (Pb) have been detected in the city. Prevention and remediation procedures could then be set to protect citizens, namely school children[5]

So how can we manage air pollution?

A famous strategy to fight a similar problem is: “Think globally, Act locally”. To fight climate change, it might be best to focus on your own environmental impact and on how you could improve the behaviours and processes of the small communities surrounding you. This strategy is relevant to the air quality issue to some extent. You can change your mobility habits, for example use public transports or a bike to replace your polluting car. This way you reduce your emissions and the air quality gets a bit better thanks to your decision. However, are you reducing your exposure to air pollution and thus improving your health? Probably not, and there is a good chance that you are exposing yourself to even more health risks.

Physical activity enhances intake of air pollutants in the lungs, augmenting their harmful effects on your respiratory and cardiovascular system.[6] Therefore, biking on city roads can be worse for your health than being in a car. Public transportation is not necessarily a better alternative. The Parisian subway was repeatedly found with levels of PM10 four to ten times higher than the EU standard of 50 µg/m3[7].

This is due to the confined space of the underground, but also because the conventional train braking system is emitting high amounts of PM.  Your personal choices to lower your air pollutant emissions does not inevitably lower the health risks you are exposed to.

The best solutions for the air pollution problem seem to be more global and societal. It’s the whole community, from individuals to industries, that need to reduce their emissions. Technologies to reduce or treat pollutant emissions already exist but are not widely spread because polluters are not obliged to implement them. Political actors have a major role to play. The EU can make the air pollution standards more stringent, forcing industrials to further treat their exhaust gases before releasing them in the environment. Countries can create financial incentives to encourage their citizens to use eco-friendly transportation or to promote less polluting energy sources. City councils can upgrade their public transportation network, build bike lanes or call for proposals from private companies to create urban air cleaning facilities. To support these solutions, it is key to properly monitor air quality. Since it is a political problem, communication to the public on their exposure and associated health risks has a major role to play.

An opportunity to promote sustainability

Appropriate public actions would provide cleaner air and lower the economic and human cost of air pollution to societies. Moreover, stricter regulation on air quality is the main source of economic growth for the sector as companies need to monitor and treat their emissions and their interior air quality.[8]  This would also create jobs to design, install, monitor and maintain the new facilities.

Overall, air quality management will be essential to drive societies towards sustainable development.