• The Catalan Aerobiological Network (XAC) of the ICTA-UAB and the Department of Animal Biology, Plant Biology and Ecology of the UAB (BABVE) will show pollen concentrations in the air in real time at the station of the campus (Cerdanyola del Vallès) from this spring a new and revolutionary automatic monitoring system.

  • The Catalan Society of Allergy and Clinical Immunology (SCAIC) recalls that 2.5 million people suffer from an allergic disease in Catalonia, and the figure will double in 2050. Suffering from respiratory allergy does not predispose to suffering from a disease severe for COVID-19.

Spring pollination will be high and may reach above average levels after the recent rainfall, but normal pollination levels are expected during the summer.

This is indicated by the forecasts of pollen and spore levels in the environment in Catalonia for the coming months conducted by the ICTA-UAB Aerobiological Network of Catalonia (XAC) and the UAB Department of Animal Biology, Plant Biology and Ecology (BABVE), led by researcher Jordina Belmonte.

A rainy November in a large part of the territory (which filled the aquifers and provided water to plants) and a milder winter than usual have allowed for important blooms and pollination during the winter (especially cypress, hazel, ash and alder) and predict an advanced pollen spring, which has been slowed down by the drop in temperatures over the past few days. Meteorological predictions (available at Meteocat https://www.meteo.cat/wpweb/prediccio/prediccio-mensual/) indicate that spring will be slightly warmer and less rainier than usual. 

With this information, the XAC forecasts that:

  • At the beginning of 2022, winter pollinations of cypress, hazel, ash and alder were significant, on several occasions exceeding the historical average concentrations registered from 1994 to the present and advancing the onset of the allergy risk period. However, no prolongation of pollination has been observed.

  • In 2022, spring pollination (plane trees, pine, parietaria, poplar, willow, maple, mulberry, grass, and also soon birch, orache and plantains) is likely to start as usual and strongly but may be shorter than usual in duration.

These predictions may be modified should this occur:

  • Temperatures are not as high as expected, which would make it possible to extend pollination of plants (especially herbaceous plants).

  • Episodes of rainfall which, if heavy and during the daytime, would pull the pollen down to the ground and also provide the water needed by plants preparing to bloom, especially grasses, and could help increase pollination and prolong the period of presence in the air of parietaria, orache, plantain, olive trees and artemisia, mainly.

  • Very strong episodes of wind coming from directions with little or no pollen (such as from the sea into land), which could lower the concentrations and modify the composition of the spectrum.

In Catalonia, the XAC (promoted by ICTA-UAB and BABVE) has been studying the diversity and levels of airborne pollen and fungal spores since 1983 by means of sensors located in 9 locations: Barcelona, Bellaterra, Girona, Lleida, Manresa, Planes de Son, Roquetes-Tortosa, Tarragona and Vielha.

Now, a new project by the AEI (AtPollenFluo), in collaboration with the XAC and the companies Swisens and Qualitas4Health, will soon make it possible to show measurements of pollen concentration in the air in real time on the UAB campus (Bellaterra, Cerdanyola del Vallès), and for the first time in Catalonia, Spain and the Mediterranean. The SwisensPoleno Mars device, on loan from the company Qualitas4Health, has been installed on campus, together with the traditional Hirst sensor, and will remain there for several months. The XAC team, with the support of Qualitas4Health, is training it to recognise the pollens in our area, and Swisens is collaborating in the generation of the algorithms needed to convert the holograms recorded into pollen types.

"It is quite a challenge, and there is still a lot of work ahead, but this spring we will publish on the XAC website the real-time readings of the main pollens found in the air," says researcher Jordina Belmonte, who stresses that "acquiring contrasted equipment at an affordable price will allow in the near future to know the pollen content in the air in real time, and will contribute to significantly improving the quality of life of people with allergies, as well as the diagnosis, treatment and prevention of respiratory allergies”.


Prevalence of respiratory allergy in Catalonia

Dr Lorena Soto, allergist at the Hospital de la Santa Creu i Sant Pau and coordinator of the Respiratory Allergy Committee of the Catalan Allergy and Clinical Immunology Society (SCAIC) explains the prevalence of respiratory allergy and its importance, whether in the form of rhinitis, conjunctivitis and/or allergic asthma in both children and adults, how it can be aggravated by pollution, and how to differentiate it from COVID-19.
Caring for allergy sufferers in Catalonia is complicated, according to the SCAIC (www.scaic.cat), which points out that 2.5 million Catalans suffer from allergic diseases and that the figure will double by 2050, increasing health, social and family costs, making it essential to have a specialist in allergology to treat this systemic disease.
Among allergic diseases, respiratory allergy is the most common in both children and adults: 25% of the population suffers from rhinitis and/or allergic conjunctivitis, and up to 12% suffer from allergic asthma. In our environment, respiratory allergy is mainly caused by dust mites, domestic animals and pollens. The pollens that cause most sensitisation are those of grasses, plane trees, olive trees, cypresses, parietaria and oraches. Alternaria fungal spores are also a major source of allergic symptoms. Very often, these patients suffer from other allergic manifestations at the same time, such as food allergies, anaphylaxis or atopic dermatitis, among others. Allergology is the only medical speciality that can provide a comprehensive approach.

Respiratory allergy and pollution

Dr Lorena Soto explains the direct relationship between respiratory allergy and environmental pollution. The emission of polluting particles into the atmosphere alters the structure of pollen, causing it to generate stress proteins as a defence mechanism, increasing its capacity to induce an allergic response in susceptible individuals. This effect is more evident in environments with high pollution concentrations. "During the confinement and mobility restrictions of motorised vehicles there was temporarily a beneficial effect for people suffering from respiratory diseases, including allergy sufferers. But during the phasing out of vehicle mobility restrictions, air pollution levels returned to those of previous periods, with a consequent worsening of respiratory allergies," he says.

Respiratory allergy and COVID-19

Currently, respiratory allergic diseases (rhinitis and/or allergic asthma) have not been shown to be a risk factor for serious complications of a COVID-19 infection. Although some symptoms of COVID may be similar to those of respiratory allergy, health professionals remark the importance of differentiating and not confusing the two. The main symptoms described in SARS-CoV-2 coronavirus infection are fever, dry cough, sore and/or sore throat (pharyngitis), difficulty breathing, and occasionally extra respiratory symptoms such as tiredness, difficulty concentrating or gastrointestinal symptoms, among others.
Respiratory allergy is characterised by a predominance of mucus, sneezing, nasal congestion, and itching of the nose, eyes, throat or inside the ear, dry cough, wheezing, and tightness of the chest with a choking sensation. Respiratory allergy to pollens intensifies when the allergic person is outdoors and at certain times of the year (mostly in spring, but not exclusively). Respiratory allergy sufferers allergic to indoor allergens (predominantly dust mites and pets) will be worse in indoor environments. In all cases, early diagnosis, health education, allergen immunotherapy or vaccines improve the quality of life of sufferers. Keeping informed about current pollen levels in the air also helps patients to better manage their condition.

The Aerobiological Network of Catalonia (XAC): measuring atmospheric pollen and fungal spores

The XAC website (https://aerobiologia.cat), Instagram @punt_informacio_aerobiologica and Twitter @aerobiologia accounts publish a weekly bulletin with predictions on the levels of pollens and allergen spores expected over the coming days, as well as graphs showing the dynamics of pollens and spores throughout the year and in comparison with previous years, pollen calendars, allergenic plants, and other information of interest on aerobiology. The forecast can also be consulted in some Apps (El Temps, Farmacias ecoceutics) and services developed by third parties (Bot Telegram, Alexa Skills, Ajuntament de Cassà de la Selva, etc.) from the XAC API. Information about the different services can be found at https://aerobiologia.cat/pia/ca/consult

The XAC project was born with the aim of turning into public service what was initially considered as research into the doctoral thesis of its current coordinator, Jordina Belmonte. The XAC is possible thanks to the contribution of resources by some administrations and companies to whom we also express from here and once again our gratitude: Laboratorios LETIPharma, Diputació de Tarragona, Servei Meteorològic de Catalunya, Sociedad Española de Alergología e Inmunología Clínica (SEAIC), Societat Catalana d'Al·lèrgia i Immunologia Clínica (SCAIC), Master in Neuromarketing UAB and UAB. Also to the AtPollenFluo project (PID2020-117873RB-I00), Swisens and Qualitas4Health.


Dra. Jordina Belmonte Soler
Coordinadora  PIA i XAC
Professora BABVE i Investigadora ICTA
Universitat Autònomade Barcelona


Dra. Lorena Soto Retes
Presidenta CAR - SCAIC
Hospital Santa Creu i Sant Pau (Barcelona)


Àrea de Comunicació  ICTA-UAB
Isabel Lopera

Telf. 93.586.86.52