Microplastic particles at the top of the Pyrenees
Taking a breath of fresh air in the mountains, soon the image will be no more than a myth. In any case, this is what the work of our colleagues from Toulouse and Grenoble, published a few weeks ago in the journal Nature Communications, seems to suggest. The idea of clean mountain air takes a big hit. At the beginning of the twentieth century, however, columns of sufferers came to the mountain sanatoriums to be treated, far from pollution, attracted by the reputation of good air and sunshine. To take a good breath of pure air in the mountains, soon the image will be a myth. In any case, this is what seems to suggest the work of our fellow researchers from Toulouse and Grenoble published a few weeks ago in the journal Nature Communications. The idea of clean mountain air takes a big hit. At the beginning of the twentieth century, however, columns of sufferers came to the mountain sanatoriums for treatment, far from pollution, attracted by the reputation of good air and sunshine.
The problem of plastic and its microparticles
Today, the invasion of plastic in our lives is more and more publicized. It is difficult to ignore this information. The accumulation of plastic waste in the oceans has led to the constitution of a mass in the Pacific Ocean, a mass so gigantic that it has been nicknamed the "seventh continent" (its surface is equivalent to three times that of France, or 1.6 million km²!). The plastic that is found everywhere is not only a threat to biodiversity, it can also affect our health, absorbed without our knowledge in the form of very small particles. More and more studies point to the presence of this microplastic in the food we ingest and especially in the water we drink because there is no filtration system capable of retaining these particles. Moreover, in June 2019, a WWF report made a lot of news. According to this report, we would swallow 5 grams of plastic per week, the equivalent of a credit card! Since then, the WWF's calculation has been strongly criticized because the highest values have been retained.
(photo credits: Milwaukee independent)
Microplastic in the air we breathe
Except that this calculation did not take into account the microplastic that we... breathe. What do you mean, we breathe plastic? Well yes! As surprising as it may seem, it is a reality in today's world! In the city of Beijing, for example, a study showed that there are between 5600 and 5700 plastic microparticles per cubic meter of air. The outdoor air in California contains 0.7 to 19.6 microplastics per cubic meter and the air in Paris contains 0.3 to 1.5 microplastics per cubic meter. This microplastic comes from agricultural activities, industry and landfills. During a normal breath, each person inhales and exhales about half a liter of air. That's a minimum of 14,000 liters of air (14 cubic meters) breathed in each day with just normal activity. This figure increases when we make an important physical effort, like running or climbing a mountain. Thus, a Parisian inhales nearly 13 microparticles of plastic every day, compared to 80,000 for a person living in Beijing, a figure that makes your head spin!
Are the mountains spared?
What about the good pure mountain air? Is it preserved from this pollution? Our colleagues suspected not. Indeed, a previous study had shown that snow samples collected in various sites, from the French Alps to the Greenland icebergs, via the Arctic, contain plastic microparticles probably transported there by the wind, a wind that in passing transports other contaminants such as mercury. With this in mind, our colleagues installed a pump at 2877 meters above sea level, at the Pic du Midi Observatory, in order to filter the air during the four summer months. After all that I told you, you probably won't be surprised to learn that they detected plastic microparticles there. Yes, even the good clean mountain air is contaminated! Reassuring, isn't it?
Our colleagues observed particles of various sizes, ranging from 0.09 to 0.66 particles per cubic meter of pumped air. These particles go by the sweet names of polyethylene (44%), polystyrene (18%), polyvinyl chloride (PVC, 15%), polyethylene terephthalate (14%) and polypropylene (10%). If I take up my calculation from earlier, if you decided to spend a day at the Pic du Midi Observatory and climb it without making any effort, you will still breathe between 1 and 10 plastic particles. And much more if you courageously climb on foot. Fortunately, these figures are far from those of Paris and especially those of Beijing. Phew!
But where does this pollution come from? Atmospheric air movement modeling has revealed that it can come from as far away as 10,000 km! Thus, it is hard to believe that there is still a small part of the planet spared from this new form of pollution.
To your health!