Spain Faces Prolonged and Intensifying Allergy Season Due to Climate Change and Wind Patterns
Spain is bracing for a longer and more severe allergy season, impacting an estimated eight million people. Experts confirm the season is starting earlier and lasting longer, driven by climate change and complex wind patterns that influence pollen dispersion. A recent Spanish study analyzing 23 years of pollen and meteorological data (2001-2023) revealed that flowering now begins and ends almost four days earlier each year.
The Expanding Pollen Season and Key Pollens
The extension of the pollen season is particularly concerning because grasses are the most common cause of respiratory allergies in Spain. Different grass species respond uniquely to weather conditions, contributing to the variability of pollen levels. Key pollens impacting allergy sufferers in Spain include those from cypress trees (January-March), birch trees (April, particularly in the Galicia region), Platanus hispanica (March-April), grasses (April-June), olive trees (April-June, especially in southern regions like Jaén, Sevilla, Granada, and Córdoba), Parietaria (April-July, along the Mediterranean coast – Barcelona, Murcia, Valencia), and Chenopodium and/or Salsola (July-September).
The Role of Wind in Pollen Dispersion
Wind plays a crucial role in both the accumulation and dispersion of pollen. Researchers at the University of Córdoba (UCO) used inverse trajectory calculations of air masses to understand wind’s influence. They found that wind patterns differ in two phases of the pollen season:
- Pre-Peak Pollen Phase: Gentle winds and short air mass travel distances favor pollen accumulation near its source.
- Post-Peak Pollen Phase: Stronger winds concentrate pollen initially and then facilitate greater dispersion as the season ends.
“Once the pollen is in the atmosphere, the wind is the main agent that conditions its dispersion,” explains Miguel Ángel Hernández, a researcher at the UCO and lead author of the study.
Rainfall and Microparticle Formation
Intermittent rainfall exacerbates allergy symptoms by fragmenting pollen grains into numerous microparticles. These microparticles, laden with allergenic proteins, are smaller than the original pollen grain and remain suspended in the air for longer periods, even without wind. Abundant autumn rainfall can prevent the complete drying of some species, potentially impacting the subsequent pollen season.
Regional Variations and Future Outlook
While the study’s findings are broadly applicable, the specific impact of wind patterns varies by region. For example, in the Mediterranean region, winds originating from the sea generally cause less severe allergy episodes than those from the west.
Experts anticipate an intense pollen season this year, with high concentrations. Favorable spring weather could further prolong the season. The ultimate goal of this research is to provide authorities with data to warn the public about potential pollen spikes.
Expert Advice for Allergy Sufferers
To minimize allergy symptoms, consider the following:
- Avoid outdoor activities during peak pollen hours.
- Use air purifiers and keep windows closed to reduce pollen exposure.
- Consider immunotherapy (allergy shots) for long-term relief.
- Consult a doctor before self-treating with antihistamines or nasal corticosteroids.
- Minimize exposure by staying indoors during peak pollen times.
- Use allergen-blocking nasal masks when outdoor exposure is unavoidable.
- Avoid raw fruits and vegetables that may trigger oral allergy syndrome (particularly during birch pollen season).
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