Air quality in Ile-de-France

How bad is the air pollution in Île-de-France?

Île-de-France is a state that encompasses some of the more famous cities in France, being known as the most populous out of all 18 regions countrywide. It finds itself in the north central region and is locally known as ‘region Parisienne’ due to it containing the capital city.

Statewide there are some 12.2 million inhabitants, making it home to a considerable amount of people. Pollution in Île-de-France varies from city to city, with some coming in with higher yearly averages whilst others sit at a good level of air quality, within the World Health Organizations target goal of 0 to 10 μg/m³ of PM2.5 in the air. PM2.5 refers to any particulate matter than is 2.5 or less micrometers in diameter, making it around 3% the size of a human hair and thus extremely small and hazardous to breathe.

When observing these PM2.5 readings across Île-de-France, the city that came in with the highest level of pollution was Saint-Denis, with a 2019 yearly average reading of 16.3 μg/m³, placing it into the ‘moderate’ pollution bracket, albeit on the lower end of the spectrum. A moderate pollution rating requires a reading of anywhere between 12.1 to 35.4 μg/m³ on the PM2.5 scale to be classed as such.

Whilst Saint-Denis came in with the highest level of pollution out of all twelve cities ranked, there is a wide variety of groupings across them, ranging from moderate all the way down to the WHO’s target goal, with five out of the twelve cities coming within the 0 to 10 μg/m³ range, making their air of a very good quality to breathe. After this, there were four cities that came in with a ‘good’ yearly ranking, which requires a PM2.5 reading of 10 to 12 μg/m³, a very fine margin for a classification yet still indicative of an overall great quality of air.

So to summate, there are five cities that are already achieving a great quality of air year-round (with the exception of some of the earlier months of the year, which will be discussed in further detail), four cities that are achieving a good level of air quality, and three cities that are sitting in the moderate yearly average bracket, meaning that there may be room for improvement.

What are the main causes of pollution in Île-de-France?

Looking at some of the more polluted cities in Île-de-France, their decreased air quality often come from a similar source. The largest offender, particularly in cities such as Paris and Melun (2^nd and 3^rd place out of most polluted cities in Île-de-France) is emissions from vehicles, with large amounts of smoke, haze and contaminants being released, causing higher levels of US AQI to show up as well as higher levels of PM2.5 and PM10 to permeate the air.

With a large variety of vehicles such as cars and trucks populating the roads, they would be releasing a sizeable amount of pollutants such as nitrogen dioxide (NO₂) and sulfur dioxide (SO₂), with nitrogen dioxide being of chief concern due to the higher quantities released from exhaust fumes. Other causes of pollution would be, besides the transportation industry, heating for homes and businesses, as well as emissions given off by factories, although as previously mentioned it is the large volume of traffic that is responsible for the higher year-round ratings, as well as being responsible for the release of ozone (O₃) and carbon monoxide (CO), with heavy metals such as lead also finding their way into the atmosphere via car fumes.

According to Airparif, an organization that monitors the levels of air quality in Paris, heating of homes and businesses is also of concern, with the numbers during the colder months reflecting this with their higher readings of PM2.5. Every city in Île-de-France came in with heightened readings of PM2.5 starting around October and peaking somewhere around January to February before declining back to more normal numbers.

As an example, the cleanest city in the state, Fontainebleau (with a yearly average of 7.4 μg/m³), came in with PM2.5 readings of 10.3 μg/m³ in January 2019, followed by 12.9 μg/m³ in February, putting it into the moderately polluted bracket. After this, its numbers quickly fell back into the WHO’s target goal for the rest of the year, showing that the colder months of winter consistently correlate with higher readings, due to the overuse of heating, or rather the non-sustainable methods by which this heat is produced and delivered (via the burning of fossil fuels). Other causes would be industrial areas, which rely on heavy machinery powered by fossil fuels for energy, which release their own types of pollutants into the air, with transportation and heating coming in at the top spots for pollution causes in Île-de-France.

Does living in Île-de-France affect health?

Whilst the overall levels of air quality in Île-de-France are indeed quite respectable, this would largely depend on which city out of all 12 in the state that one spends the majority of their time in. Whilst even in the most polluted cities, such as Saint-Denis and Paris (1^st and 2^nd place), pollution levels never rose above 26.3 μg/m³ for Saint-Denis and 23.4 μg/m³ for Paris.

Whilst these readings could affect those with a sensitivity towards pollution, or sufferers of respiratory issues such as bronchitis or asthma, these readings pale in comparison when compared to a more polluted city such as Delhi in India, which in the year of 2019 had its cleanest reading of 31.9 μg/m³ in August, already above Paris and Saint-Denis’s highest readings, but by huge contrast, had its worst reading in November coming in at 200.7 μg/m³, placing it well into the ‘very unhealthy’ bracket, which requires a reading of 150.5 to 250.4 μg/m³ to be classed as such.

This is merely for comparison, and not to minimize the pollution that certain cities in Île-de-France suffer from. As mentioned, whilst it does not endure the catastrophic readings that a city such as Delhi has, the earlier months of the year with their higher levels of smoke, haze and PM2.5 readings, may have some health consequences, some of which will be discussed in greater detail.

Of note is that for those who live in the cities that see a majority of their months fall into the WHO’s target goal (such as Fontainebleau and Blandy), they would be breathing air that is of very good quality for most of the year.

What are some health symptoms of breathing polluted air in Île-de-France?

For the cities across the state that fall into the moderate ratings for a majority of the year, as the numbers of PM2.5 in the air become elevated, so too do the possibilities of negative health effects occurring. These would include many respiratory ailments, with bronchitis, emphysema and aggravated asthma attacks all being possible, particularly in those who may have compromised immune systems or are prone to respiratory illnesses.

Others would include higher rates of cancer, particularly of the lungs due to PM2.5’s (and to a lesser extent PM10’s) ability to penetrate deep into the lungs where it can accumulate. Besides heightened rates of cancer, it can also cause scarring of the lung tissue and an overall reduced capacity, with finely ground materials such as silica dust (given off largely by construction sites) all able to cause this internal damage, as well as other materials with carcinogenic properties such as benzene finding their way in.

For pregnant mothers who are exposed to prolonged bouts of pollution, as experienced more prominently in the earlier parts of the year (with the overall ‘clean’ air quality city of Chatou coming in with a fairly high reading of 29.7 μg/m³ in February 2019), there may be a host of problems such as increased rates of miscarriage, babies born prematurely or with a low birth weight.

Other issues would include damage to the liver, kidneys as well as the reproductive systems. With the knowledge of these ill effects all being a real possibility, preventative measures such as wearing particle filtering masks or avoiding outdoor activity during the worst months may be helpful in reducing the chances of such incidences occurring, as well as staying up to date on the pollution levels via air quality maps as available on the IQAir website, or the AirVisual app.

When are the cleanest months in Île-de-France?

Observing the data taken over 2019, it is clear that Île-de-France has its best quality of air, across all cities, in May through to September. October still sees some cleaner ratings, although it is around this time that a decline in the air quality starts to become apparent, with cities such as Paris seeing a jump from 9.6 μg/m³ in September (WHO target rating) up to 12.7 μg/m³ in October (moderate pollution rating), proof of the sudden decline, with other cities also jumping up a bracket or two from September to October.

Some of the best readings statewide were also taken in September, making it officially the cleanest month of the year. Fontainebleau came in with a very low reading of 4 μg/m³, whilst Blandy also came in with 4.6 μg/m³, as well as Chatou coming in at 4.2 μg/m³. This unanimously makes September the cleanest month across Île-de-France, with the months preceding it also coming in with good numbers, making the middle of the year the time when the air is of the highest quality, devoid of smoke, haze and other unwanted particulate matter.