Alerta en Castilla y León por intrusión de polvo africano

June 9, 2025

Castilla y León | Department of Environment, Housing, and Urban Planning

Prediction models announce the intrusion of dust particles from North Africa, which are expected to cause an increase in measured levels of these substances in the air from today, June 9 in the afternoon until Wednesday, June 11, throughout the territory of Castilla y León. This is a completely natural process over which human intervention is not possible, except for taking precautions to minimize exposure to these particles.

This alert is predictive, as the information is available through air quality models for PM10 particles (particles smaller than 10 microns). The prediction indicates that values above 50 μg/m3 as a 24-hour moving average may be reached, determining very unfavorable air quality.

Although the Air Quality regulations in Spain and Europe do not establish an information threshold to the population for this contaminant, the Department of Environment, Housing, and Urban Planning recommends measures to minimize the impact of these particles:

• If levels are not very high (up to regular): for the general population, although the predicted air quality during these hours may not affect them, it may pose a moderate risk for at-risk groups and sensitive individuals. Therefore, enjoy outdoor activities as usual, but monitor for symptoms such as cough, throat irritation, shortness of breath, excessive fatigue, or palpitations.
• If levels are higher (>regular), at-risk groups and sensitive individuals such as those with cardiovascular or respiratory diseases or severe allergies should consider reducing prolonged and vigorous outdoor activities. Those with asthma or respiratory diseases should carefully follow their medication plan. Individuals with heart problems may experience palpitations, difficulty breathing, or unusual fatigue.

Since the magnitude of the intrusion will vary depending on the time of day and the coming days, it is recommended that anyone planning outdoor activities be informed about the air quality in their area by accessing the websites indicated below.

Furthermore, it is also advised to avoid actions such as outdoor burning of plant residues and, in general, any activity that could emit particles in order to minimize the effects of this episode.

The Department of Environment, Housing, and Urban Planning will monitor this episode, and real-time air quality data for the community can be consulted at the following:

Department of Environment, Housing, and Urban Planning

Ministry for Ecological Transition and Demographic Challenge

European Environment Agency

Air Quality Index (ICA) app available on the App Store

For the interpretation of real-time data and in accordance with Order TEC/351/2019, of March 18, approving the National Air Quality Index, the reference values, as daily averages, would be as follows:

Particles smaller than 2.5 microns (PM2.5)

1. Good 0-10 μg/m3
2. Reasonably good 11-20 μg/m3
3. Regular 21-25 μg/m3
4. Unfavorable 26-50 μg/m3
5. Very unfavorable 51-75 μg/m3
6. Extremely unfavorable 76-800 μg/m3

Particles smaller than 10 microns (PM10)

1. Good 0-20 μg/m3
2. Reasonably good 21-40 μg/m3
3. Regular 41-50 μg/m3
4. Unfavorable 51-100 μg/m3
5. Very unfavorable 101-150 μg/m3
6. Extremely unfavorable 151-1200 μg/m3