Occitanie is a state located in the southernmost portion of France, being the second largest region countrywide and home to some 5.8 million inhabitants. Occitanie has five cities within it, and finds a good portion of its landmass facing onto the Mediterranean coastline. Due to having a large portion of land facing the coast, Occitanie is subject to quite good levels of year-round pollution, although this is not always the case with coastal cities or states.
In 2019, every single city in the state came in with a PM2.5 reading that was within the World Health Organizations (WHO) target goal of 0 to 10 μg/m³. PM2.5 refers to particulate matter that is of 2.5 micrometers or less in diameter, and due to its size has highly adverse effects on those breathing it. As such it is a major component in calculating the overall levels of air pollution in any given area.
As it stands, Occitanie has low year-round readings of PM2.5, with the most polluted city state wide, Poitiers, coming in with a reading of 9.6 μg/m³, a very respectable number in terms of the quality of the air. Of note is that this city did have some months that broke out of the WHO’s target goal and actually went up by several rankings, although these were short lived and the readings were not high enough to skew the average data by any significant number.
The highest reading statewide over the whole year of 2019 was 20.4 μg/m³, recorded in February in Poitiers, putting it into the ‘moderate’ pollution bracket which requires a PM2.5 reading of 12.1 to 35.4 μg/m³.
Whilst this number could be considered quite high, and when compared to the rest of the year it certainly comes in many magnitudes higher (compared to a reading taken in Peyrusse Vielle of 3.6 μg/m³ in November), this number quickly declined and by next month it had already dropped by nearly half back down to 11 μg/m³, putting it in the ‘good’ group rating (10 to 12 μg/m³) and then followed by a reading of 10 μg/m³ in the next month, inching its way back into the WHO’s target goal once again. There are other cities with similar stories, and as such the state of Occitanie has a great level of year-round pollution, with some months that occasionally jump higher than others before quickly declining back to safe levels of air quality.
As is common in many cities and states across France, and indeed worldwide, pollution sources remain the same, with varying issues occurring world wide (such as the illegal practices of slash and burn farming causing large amounts of smoke and pollution in Thailand).
For the cities of occitanie, they find their sources of pollution stemming from the use of vehicles, as well as the heating of homes and places of business, particularly during the colder months of the year which can be directly observed on the PM2.5 readings of years past. Other issues that raise the overall levels of pollution year-round are industrial factors, with places such as factories also giving off their own pollutants due to them being powered by non-renewable sources such as coal. There are a large amount of factories in the deep south of France, many of them catering towards the production of clothes and branded goods, with industry giants such as Nike even having production lines in Occitanie.
With studies taking place around major cities such as Toulouse, it is shown that nearly all, if not the entirety of nitrogen dioxide (NO2) emissions can be found in the atmosphere surrounding main roads, and although these levels fell slightly over the year of 2020 due to COVID-19 lockdowns being in effect, when normal activity resumed these levels of pollution returned to normal, showing the prominent effect that motor vehicles can have on the pollution levels. Of importance as well is the pollution given off from the heating of homes, showing just as much prominence as emissions given off by diesel fuels. The effects that these pollutants have on the environment and human health will be discussed in short.
Observing the date taken over 2019, it is apparent that much like the rest of France, Occitanie suffers from spikes in PM2.5 during the colder months of the year. Looking at the readings taken from the various countries statewide, Poitiers had all its elevated pollution ratings in the months of January, February and December. They all came in with readings of 14.9 μg/m³, 20.4 μg/m³ and 12.2 μg/m³ respectively, along with March also coming in slightly elevated with a PM2.5 reading of 11 μg/m³. As touched on previously, the rest of the year was all within the WHO’s target.
Other cities all fell in line with similar readings, with Toulouse showing elevated readings in January, February, November and December. Lourdes, with a yearly average of 8.2 μg/m³, showed heightened numbers in the first two months of the year, however it was void of the large jumps in November and December that were seen in the top two cities in Occitanie.
With these trends, it is apparent that there will be constant spikes in pollution at these times of the year, and as such any people who suffer from sensitivities towards airborne chemicals or those with respiratory issues may want to stay up to date on pollution levels during these months, via the use of air quality maps as available on the IQAir website, or also on the AirVisual app.
With this knowledge at hand, preventative measures can be taken to ensure exposure to pollution is kept to a minimum, either through the avoidance of outdoor activities during particularly bad spells, or through the wearing of fine particle filtering masks.
Once again going off the data provided over the last few years, we can compare the yearly averages from each different city to see if any marked improvements have been made, or whether there has been a reduction in the quality of the air. Besides just having PM2.5 as a way of measuring pollution levels, US AQI (united states air quality index) is often used as an overall calculation of air quality, taking factors such as PM2.5 and other pollutants (CO, PM10) and using them to obtain a US AQI rating. The reason why the united states air quality index is used is because of how strict its rating system is when compared to other international air quality measures.
Regarding pollution levels in Occitanie, it is indeed shown that pollution levels are improving slowly across every city, with many of them moving down a ranking from ‘good’ levels of air quality (10 to 12 μg/m³) down into the WHO’s target. Poitiers came in with an average PM2.5 reading of 11.1 μg/m³ in 2017, followed by a reading of 9.9 μg/m³ in 2018, and then finally a reading of 9.6 μg/m³ in 2019. This is a definitive improvement each year.
Other cities that followed suit were Toulouse, coming in at 10.9 μg/m³ in 2017, 10.1 μg/m³ in 2018 and then 9.2 μg/m³ in 2019. Every city came in with this trend, the most prominent difference being in the cleanest city of Peyrusse Vieille, which had a PM2.5 reading of 10.7 μg/m³ in 2017, which dropped down to 6.7 μg/m³ in 2019, showing a considerable improvement over the span of two years.
With a large amount of its pollution coming from vehicular emissions, factory smoke and fine dust as well as the burning of fossil fuels during colder months for heating, there would be a wide variety of pollutants in the air, particularly when the levels of PM2.5 reach higher numbers, as observed in Poitiers with its highs of 14.9 and 20.4 μg/m³.
Pollutants such as black carbon and volatile organic compounds can be found accumulated in road dust as well as the atmosphere, both of which are a byproduct of the combustion of organic material or fossil fuels, and as such can find their origins in factories, the burning of wood or other materials done by the general population, as well as from engines that run on diesel fuels.
Nitrogen dioxide is always present in large quantities in areas that see high volumes of traffic, as well as sulfur dioxide (SO2) along with it. Sulfur dioxide may be even more present along coastal towns due to the existence of boats in these areas. Larger ships often have different regulations on the fuel they can use, and as such they often contain higher levels of pollutants such as sulfur, which can cause problems to the surrounding air in the form of sulfur dioxide, causing acidification of the clouds which leads to increased rates of acid rain.
Other chemicals or compounds that arise from factory and vehicle emissions, or a combination of both, include dangerous materials such as benzene, formaldehyde, dioxins as well as metals such as mercury or lead, particularly in factories that work with plastics, as well as construction sites. The most pertinent pollutants for the state of Occitanie however, would be nitrogen dioxide, ozone (O3) and the wide variety of fine particulate matters that fall under the PM2.5 and PM10 bracket.