In the same way that winter pollens (such as cypress, ash and hazel) have been delayed by the winter cold, preventing the plants from starting to release significant amounts of pollen until early March, spring pollens will also suffer a setback as a consequence. of the recent episode of low temperatures. In neither case is this good news. Trees like the cypress, which have accumulated large amounts of pollen, could now suddenly release them with very high concentration peaks, causing people who have never suffered from allergies to develop them. Likewise, between next week and the last week of March, the plane tree and the parietaria, for example, both of which are very allergic, could begin to release notable amounts of pollen, affecting allergic people. This is predicted by researchers from the Institute of Environmental Science and Technology of the Autonomous University of Barcelona (ICTA-UAB), who today presented the pollen forecast for spring 2023 in Catalonia.
"This winter, with the weather that it has done, the plants that pollinate in this season have hardly done so due to not having good conditions, but they have produced flowers that are now loaded with pollen and that other years had been releasing it" Jordina Belmonte, a researcher at the ICTA-UAB and head of the Xarxa d'Aerobiologia de Catalunya (XAC), explains to La Vanguardia.
Earlier this year, winter pollinations of cypress, hazel, and ash fell to record lows from 1994 to the present, delaying the onset of the allergy risk period until recently. Hence, the forecast for the pollination of the cypress speaks of the fact that it can extend until well into the month of April.
“What can happen is that trees like the cypress release a lot of pollen at once and there are very important peaks. People who are already allergic will not be harmed by more pollen being released, because they will already have been affected by the amount their body reacts to. But, on the other hand, it can happen that others who have never suffered from this allergy, because there is so much pollen in the air, become allergic”, argues Belmonte.
For this reason, he advises these people who are more sensitive to these winter plants to "be careful, because this scenario can occur." And what can be done to minimize the symptoms? To begin with, get as far away from these types of trees as possible, says Belmonte. The use of masks is also advisable, "to reduce the amount of allergen that reaches them", as well as sunglasses. "You have to go out protected so you don't breathe in those particles that hurt them."
On the other hand, the meteorological models indicate that the spring will be slightly warmer than usual and that the month of April will be rainy. With this information, the forecast of the levels of pollen and spores in the atmosphere in Catalonia for the coming months carried out by the XAC of the ICTA-UAB and the Department of Animal Biology, Plant Biology and Ecology of the UAB (BABVE) suggests that spring pollinations (poplar, banana, pine, parietaria, willow, maple, mulberry, grass and later those of birch, ceñigo, plantain and olive) will follow the trend of starting with a certain delay, but strongly, and could last shorter than usual.
"When the temperature is higher, pollination tends to last less," argues Belmonte. In addition -he continues-, "if it rains in April and it rains during the day, when there is light and the plants emit pollen, that rain would take it to the ground, removing it from the air. Sometimes, when we have had a rainy April, which is when there are a lot of flowering plants, if the pollen has ended up on the ground due to the precipitation, allergy sufferers have noticed it positively”, adds this researcher.
According to the XAC, the most abundant types of allergenic pollen in general in the atmosphere of Catalonia are: Cupressaceae (20.8%), such as cypress; the shadow plantain (9.7%); the oleaceae (8.6%), such as olive, ash and privet; parietaria (5.3%); grasses (4.3%) and ceñigos (2.4%), with important variations in quantity according to the geographical and climatic zones of Catalonia. Alternaria fungus spores, despite their significance in allergies, are not among the most abundant in the air (between 1 and 2% of all spores).
In Catalonia there are 2.5 million people who suffer from an allergic disease, and it is expected that this figure will double in the year 2050. Anomalous weather conditions have increased the cases and complications of respiratory allergies, increasing consultations in the services primary and hospital care emergencies, with an increase in referrals to allergy services and the consequent impact on waiting lists.
The Catalan Society of Clinical Allergy and Immunology (SCAIC) estimates that 25% of the population suffer from allergic rhinitis and/or conjunctivitis and up to 12% from allergic asthma.
Doctor Lorena Soto, specialist in allergology at the Hospital de la Santa Creu i Sant Pau and coordinator of the SCAIC committee for respiratory disease, highlights the importance of asthma and allergic rhinitis, both in children and adults. These are chronic diseases of the respiratory tract that in spring complicate the health of both the already known allergic population and those who start compatible allergy symptoms. Soto stresses the need for early detection, given its relationship with other associated allergic diseases in the same person such as atopic dermatitis and food allergy.
The most prevalent sensitizations in allergic patients are to grass pollen (51.6%), plane tree (38.7%), olive tree (35.5%), cupressaceae (22.6%), ceñigo (6, 5%), parietaria (10%) and alternaria (17%).
The prevalence is higher in cities and parts of the territory with high levels of pollution. Pollution has a direct effect on allergic respiratory disease, not only because of the damage that toxic particles cause to the respiratory tract, but also because pollen alters its structure as a defense mechanism against pollution. This increases their ability to induce a nasal and/or bronchial inflammatory response, leading to more symptoms and more severe respiratory allergic crises.
The XAC, within the framework of an agreement with Qualitas 4 Health and Swisens, is collaborating in the development of an automatic observation model of pollen and other aerosols in real time based on artificial intelligence on the UAB campus (Cerdanyola del Valles).
The SwisensPoleno Mars device provided by the company Qualitas 4 Health is installed on campus, along with the traditional Hirst sensor, and they have been training it since May 2021 to recognize pollens in that area. The manufacturing company Swisens collaborates in the generation of the necessary algorithms to convert the registered holograms into types of pollen.
“The challenge in the future is to be able to report in real time what is in the air and have enough equipment at an affordable price to cover the territory in a representative manner. It will be a great step forward to improve the quality of life of people with allergies, as well as the diagnosis, treatment and prevention of respiratory allergies”, argues Belmonte.
Until this technology is definitively implemented, a bulletin is published weekly on the XAC website with the predictions of the levels of pollen and allergenic spores expected for 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.
"With these bulletins, what we want is to give clues to people to notify them of when it is possible that they may feel unwell, so that they take precautions, as many as they can," concludes Belmonte.
