Hautes-Pyrenees: air pollution warning caused by the return of wind with sand from the Sahara

This Monday, the Hautes-Pyrenees suffered from a new episode of air pollution. The phenomenon will gain momentum on Tuesday. We are talking about a new wave of wind from the Sahara, filled with sand and pollutants, which will cross the mountains from North Africa and Spain. The Atmo agency initiates the notification procedure for the Hautes-Pyrenees, Ariège and Eastern Pyrenees. Fragile people should be especially vigilant.

Particle Contamination Warning! A new air mass coming in from Spain from North Africa and the Sahara desert will bring a wave of sand and particulate matter (PM10) at levels that are considered high, with an index of 4 (poor) out of 6. Hautes-Pyrenees department only information this Monday before move to the alert threshold on Tuesday.

The Atmo agency, which measures and monitors air quality in Occitania, has initiated an alert procedure, which the Hautes-Pyrenees prefecture has announced on its social media. Particular vigilance should be exercised by people with impaired health (pregnant women, infants and young children, people over 65 years old, people suffering from cardiovascular pathologies, heart or respiratory failure, asthmatics), especially those suffering from respiratory diseases. They should avoid sports or excessively intense physical activity.

The concentration of particles increased 4 times in a few hours.

Atmo stations in the Hautes-Pyrenees indicated that fine particulate matter (PM10) levels increased sharply on Monday and reached a threshold of 53.6 µg/m3 (up from 15.4 µg/m3 at 7 a.m.). This level should rise on the night of Monday to Tuesday. Will it exceed the level of 70.7 g/m3 recorded on March 15 during the previous episode of pollution that turned the ski slopes into sand dunes?

On the side of airborne particles, which include PM10 and more important elements, levels reached 208.7 µg/m3 on Monday around 15:00 (38 µg/m3 at 7:00 am). And here the concentration can continue to increase at night, when the polluted air mass arrives. On March 15, particle concentrations reached 296.4 µg/m3 at Argeles-Gazost.

Mind-blowing session in the Sahara

The phenomenon is known. This can happen several times a year, the meteorologists of Météo France remind. The wind then deposits a more or less significant amount of Saharan sand. On March 15, sand settled on the massifs of the Hautes-Pyrenees, giving the mountain an orange tint. The slopes of some ski resorts have even taken on the appearance of desert dunes.

Like in Pio Engali, where riders could get the impression that they were skiing on sand dunes. Fans of “In pow we trust” posted some truly mind-blowing photos of their descent during the “incredible Saharan session at Pio Eglai”.

“Sand that settles on the snow not only pollutes it, but also reduces its albedo, which in the long run can accelerate melting,” warns Serge Aragon, meteorologist at Météo France.

Eventually, more snow fell on the mountains and swallowed up the sand.

The expected episode of air pollution should continue on Tuesday before fading away with the arrival of rain later in the day.

Practical advice for vulnerable people

The prefect of the Hautes-Pyrenees advises frail people to avoid intense outdoor or indoor sports and activities and to postpone the activities that require the most effort. “In case of symptoms or concerns, seek the advice of your pharmacist, consult your doctor, or contact your local health service when it is established. If you feel your symptoms are less bothersome when you stay at home, opt for shorter walks than usual.” You should also avoid going outside in the early morning and late afternoon, and near major highways. It should be noted that during the March 15 episode, firefighters and the hospital did not have a noticeable increase in activity caused by particles that came from the Sahara.