Higher and earlier pollen concentrations expected for this spring

18/03/2020

The pollination of this spring and summer will arrive a few days earlier than usual and concentrations will be high, reaching levels above average (from the 1994-2019 period). This is indicated by the forecast of pollen and spore levels in the environment in Catalonia for the following months conducted by researchers from the Aerobiology Information Network of Catalonia (XAC) from the ICTA-UAB and the Department of Animal Biology, Plant Biology and Ecology at the UAB.

The past autumn and winter have been more humid and warmer than usual. The abundance of water underground at the moment in which plants, especially trees, restart their activtity after the cold period, and mild temperatures for this time of year in which pollination begins, has translated into much blooming and pollination during the winter (particularly in cypress, ash, almond and alder trees). In addition, the weather forecast for this spring (which can be consulted at Meteocat) says that it will be slightly warmer than usual, with more amount of rain than usual, as well. 

With this information, the XAC informs that during 2020, the winter pollinations (cypress, ash, almond and alder) began early and very strongly, surpassing the historic average concentrations registered since 1994, and ended earlier too (therefore, lasting as long as it normally does); in the same manner, spring pollination (plane, pine, parietaria, poplar, willow, maple, mulberry, grass and soon also birch, orache and plantains) follow this tendency of beginning soon and very strongly and could last as long as usual, unless:

• temperatures suddenly rise steeply, which would produce an abrupt end of the plant's flowering period;
• rain during daytime, when flowers are wide open and can release their pollen. The rain would pull the pollen down to the ground. However, even if the rain eliminates pollen from the air, it also provides the water needed by plants getting ready to bloom, and could help increase pollination and prolong the period of time in which plants such as parietaria, grass, orache, plantains, olive trees and artemisias release pollen into the air;
• strong episodes of wind coming from directions with little or no pollen (such as from the sea into land), which could lower the concentrations or modify the composition of the spectrum.

Allergies and Symptoms

Allergies are the immune system's response triggered by a great variety of external substances known as allergens. These allergens can set off reactions if they are breathed in, swallowed, injected into the body or come in contact with the skin. People suffer most commonly from respiratory allegiries, with approximately 25% of the population affected with rhinoconjunctivitis and up to 12% with asthma. In our environment, allergies are mainly produced by dust mites, pollen and fungal spores. Symptoms of respiratory allergies are difficult breathing, coughing, sneezing, itchy eyes and nose, nasal obstruction, mucus, headaches and difficulty sleeping.  

Top Allergy-Producing Pollen

According to data from the SCAIC, allergy patients most often suffer from pollen produced by grasses (51.6%), plane trees (38.7%), olive trees (35.5%), cypresses (22.6%) and oraches (6.5%).

According to the XAC, the most abundant types of allergen pollens in Catalonia are cypresses (20.8%), plane trees (9.7%), the oleaceae –olive tree + ash + privet (8.6%), parietaria (5.3%), grasses (4.3%) and oraches (2.4%), with important variations in the amount depending on the geographical and climatic zones of Catalonia.

The XAChas analysed the tendency in yearly amounts of these pollens for the past 26 years, with the aim of evaluating changes in meteorological patterns (climate change) and how they influence pollination. The results make it clear that, in Catalonia, there has been a significant statistical increase in the yearly amounts of tree pollen (cypress, plane tree and olive tree), while plant pollen have decreased significantly (parietaria and orache) or non-significantly (grasses and artemisia).

Comparrison Between Allergy Symptoms and Those of the Severe Acute Respiratory Syndrome Caused by Coronavirus 2

The Catalan Allergy and Clinical Immunology Society (SCAIC) explains how to differentiate allergy symptoms from those caused by the Severe Acute Respiratory Syndrome caused by the Coronavirus 2 (SARS-CoV-2 / COVID-19). Some symptoms are similar and could lead to confusion.

Can we find the difference between the two pathologies?

The main symptoms described in COVID-19 are fever (88.7-91.7% of patients), dry cough (67.8-75%), which can cause irritation in the pharynx and lead to pharyngitis, general discomfort (75%) and difficulty breathing, sometimes accompanied by a feeling of chest tightness. Digestive diseases can also appear, although they are not as frequent. When respiratory symptoms appear due to allergies, rarely are they accompanied by fever or digestive discomfort and there is a predominance of nasal congestion and mucus, which is much less frequent in COVID-19. Patients allergic to pollen, especially in the case of parietaria, may feek an itch (not pain) on the palate and/or throat.

If I am allergic, am I at greater risk of suffering from SARS-CoV-2 / COVID-19?

The main diseases associated with this infection seem to be high blood pressure (30%), diabetes (12.1%), cardiovascular diseases and chronic obstructive pulmonary disease (to a lesser extent, 1.4 %). Therefore, until now it has not been demonstrated that allergies and asthma are risk factors when suffering from SARS-CoV-2 / COVID-19.

Are patients with asthmatic allergies in greater risk of suffering pulmonary exacerbation if infected with COVID-19?

During the SARS outbreak in Singapore or Hong Kong no asthma exacerbation was observed. This was due to the changes in lifestyle of those suffering from asthma: the closing of schools, prevention measures, use of masks, etc. However, since respiratory infections, especially viral ones, can bring on asthma crises there is a need to increase prevention measures. It is very important to follow all basic asthma treatments in order to have it under control.

Can the spring put a halt to COVID-19?

Although the majority of viruses, including some types of Coronavirus, are not as active when the temperatures rise, in the case of COVID-19, we currently do not have enough evidence of this possibility given that countries such as Singapore have also had cases although the temperatures and humidity are very high.

Medical Attention Given to Allergy Sufferers in Catalonia

The increase in allergies in the future in Catalonia will greatly be due to the number of multiple sensitivities to different allergens in one same patient. This implies multiple manifestations (asthma, rhinitis, skin rashes, anaphylaxis, and other symptoms), with a spectrum of severity caused by multiple allergens. All of this complicates the diagnosis and treatment, elevates healthcare, social and familial costs and make allergy specialists essential in treating systemic diseases such as allergies. The SCAIC uses the information provided by the Aerobiology Information Network of Catalonia given that it is a very important and necessary tool. In addition, it recommends its patients to remain updated through the XAC application in order to be informed and be able to plan their activities according to how this information evolves.

The Aerobiology Information Network of Catalonia (XAC): measures of pollen and fungal spores in the environment 

Since 1983, the XAC has been studying in Catalonia the diversity and levels of airborne pollen and fungal spore. Monitoring is current done in 9 cities: Barcelona, Bellaterra, Girona, Lleida, Manresa, Planes de Son, Roquetes-Tortosa, Tarragona and Vielha.

The XAC website offers weekly updates on allergy-causing pollen and spore level predictions, as well as graphs showing the pollen and spore dynamics throughout the year and in comparison to previous years, pollen calendars and other information of interest on aerobiology. Users can sign up on the website to receive weekly bulletins. Predictions can also be consulted on Instagram @aerobiologia_de_catalunya and Twitter @aerobiologia and on the apps used to calculate these predictions (El Temps for Android, and PolenCat for Android and IOS), and others such as the website of the Cassà de la Selva City Council and Amazon's Alexia Skills. The XAC is also available for consultations made by professionals and individuals (aerobiologia.pia@uab.cat).

The XAC project was created with the objective of being a service for the country and its citizens, and was first presented as research included in the PhD thesis of its current coordinator Jordina Belmonte. The XAC exists thanks to the financial support of administrations and companies which we hereby wish to mention and thank once again: Laboratorios LETI, Tarragona Provincial Council, Meteorological Service of Catalonia, Lleida Provincial Council, Sociedad Española de Alergología e Inmunología Clínica (SEAIC), Societat Catalana d'Al·lèrgia i Immunologia Clínica (SCAIC), J Uriach y Compañia, S.A., Master's Degree in Neuromarketing, UAB and the UAB. Also thanks to the project TECBIOMET (CTM2017-89565-C2-1-P).

Photo: XAC coordinator and ICTA-UAB researcher Jordina Belmonte with XAC technical specialist David Navarro examining the sensor located at the UAB campus.