The more pollen, the more covid-19 infections

BarcelonaPollen and covid-19 infections have a direct relationship. A worldwide study published in the scientific journal PNAS, in which the Institute of Science and Technology (ICTA) of the UAB participated with data from Catalonia, relates the increase and decrease of pollen concentration in the air with the increase and decrease of SARS-CoV-2 infection rates. According to the research, pollen grains can affect the immune system of people, and not only those who have a respiratory allergy, making them more vulnerable to catching covid-19.

According to the researcher Jordina Belmonte, "this leads us to insist on the recommendation to always use an approved mask, which will isolate us from the allergens of the abundant pollen in the air at this time of year". The masks are a good element of protection because they reduce up to 80% of the pollen particles in the air that is inhaled.

Likewise, Dr. Joan Bartra, allergist at the Hospital Clínic de Barcelona and president of the Catalan Society of Allergy and Clinical Immunology (SCAIC), recalls the importance of not confusing the symptoms of allergy with those of covid-19, although some may be very similar.

The main symptoms described in a SARS-CoV-2 coronavirus infection are fever, dry cough, tiredness and difficulty breathing, as well as gastrointestinal symptoms, although they are not so frequent. In contrast, Bartra says that respiratory symptoms caused by allergic pathology are not gastrointestinal, and instead mucus and nasal congestion will predominate, much less frequent in the case of covid-19.

"What should make us suspect allergy, especially if it is due to pollen, is that the symptoms will intensify when the patient is outdoors and improve considerably when they are indoors", he adds. In addition, Bartra points out that at present it has not been proven that allergy sufferers, 25% of the population, are at greater risk of suffering from covid-19.

Spring with stable pollen levels

Fortunately, according to data from the Aerobiological Network of Catalonia (XAC), which has been studying the diversity and levels of pollen and fungal spores in the air since 1983, pollination this spring and especially in summer will decrease compared to last year. However, they will be quite important, and the pollination level will be above average.

During 2021, pollinations have been important and have exceeded, from February onwards, the historical average concentrations from 1994 to the present. Even so, expert weather forecasts (Meteocat) indicate that the spring will be slightly warmer and less rainy than usual. Therefore, the XAC predicts that there will be an "advanced depletion of plant flowering" and grasses will "pollinate little". All in all, the spring and summer weather will help to reduce the covid-19 infection rate at this time of year, says Belmonte.

More pollination of trees

According to the XAC, in the period between 1994 and 2020 in Catalonia, tree pollen tends to increase the concentrations in the air, while grass pollen tends to decrease.

That being said, the SCAIC predicts that there will be an increase in allergies in the future in Catalonia. This will be largely due to the number of multiple sensitisations to various allergens in the same patient. This implies multiple manifestations in the same individual (asthma, rhinitis, urticaria, anaphylaxis, among others). Therefore, the figure of the allergist as a specialist trained to treat a systemic disease such as allergy is essential. 

Finally, Dr Bartra asks people with respiratory allergies to take into account where they are going for Easter and to protect themselves more. "Some destinations are more suitable than others depending on the level of pollen. You have to take this into account".