Introduced flora

Climate change brings allergy season all year round

(Bild: Albertsen Foto/stock.adobe.com)

Global warming and introduced plants are prolonging the allergy season, experts told journalists in Vienna on Wednesday. This year, warm winter temperatures caused hazel bushes to emit pollen grains as early as January, followed by trees such as ash trees. Grasses bloom in spring, mugwort and ragweed in summer and fall. Even at Christmas time, pollen from purple alder planted by city gardeners buzzes through the air, said Helmut Zwander from the Carinthian Pollen Monitoring Service.

According to the Austrian weather service Geosphere Austria, the current winter will be the second warmest since measurements began; February was the warmest ever. This extends the pollen season forward, the experts reported: "The hazel already began to bloom at the end of January, followed by the alder, which dusted until the beginning of March". There were "exceptionally high pollution peaks" for alder pollen.

Ash pollen grains were found in the measuring stations about a month earlier than the long-term average. "They also reached unusually high concentrations due to the unusually high temperatures in recent weeks," said Markus Berger from the Austrian Pollen Information Service.

High altitudes no longer a pollen-free zone
An early start is also expected for birch, according to Berger. Namely in the whole country in the third week of March. The first pollen has already been registered here too. This will be followed by the flowering of grasses and, in late summer, mugwort and ragweed. This actually marks the end of the pollen season, with only the purple alder "still disturbing the Christmas peace" in December.

"It has Siberian genes and is therefore resistant to winter", said Zwander: "In Carinthia, hazel and gray alder can also start releasing pollen on southern slopes shortly after the Christmas holidays". Even high altitudes are no longer a pollen-free zone. The pollen from the plants reaches up to over 2000 meters, he said.

Ragweed is also gradually migrating to the west of Austria
Last year, the pollen season in the east of the country had already lasted around 300 days. Due to man-made global warming, the number is increasing, according to Zwander: "The mild winter days encourage an early start to the pollen season and allow plants to flower until late in the fall".

Introduced plants cause additional problems for allergy sufferers. Ragweed was brought to Europe from the USA as early as the middle of the twentieth century. It is widespread in Vienna, Lower Austria and Burgenland, and has already spread as far west as Tyrol and Carinthia.

Allergic reactions to ragweed range from rashes to asthma.

(Bild: Evelyn Hronek)

According to the experts, the "annual mugwort" (Artemisia annua) also caused severe symptoms last year with its strong flowering in late fall. It originates from Asia and the Balkans. Autumn allergy attacks are expected to be caused increasingly by reed pollen around Lake Neusiedl in Burgenland and the Carinthian lakes.

Olive groves, which have recently been cultivated in the Pannonian lowlands, could also "in the not too distant future cause problems for people who are sensitive to pollen from olive trees". Locally, the "tree of heaven", which is currently spreading, could also cause irritating pollen to the mucous membranes.

Pollen measurements show allergy risk
Across Austria, there are 25 strategically positioned measuring points, so-called pollen traps, where the pollen content in the air is regularly measured, Berger reported. Because allergic symptoms are dependent on wind and weather and are exacerbated by air pollution, the Pollen Information Service takes into account not only local pollen data but also weather data and calculates the influence of ozone, sulphur dioxide, nitrogen dioxide and particulate matter.

The flora of neighboring countries is also included, as air currents carry their pollen unhindered across borders. All this data can be used to determine a personal allergy risk very accurately, he explained. It can be accessed via a free app (called "Pollen+") or the website of the Pollen Information Service.

Allergy sufferers very restricted in everyday life
In Austria, one and a half to two million people suffer from "hay fever" caused by contact with pollen, said Fritz Horak from the Allergy Center Vienna West. Typical symptoms include a runny or blocked nose, itchy eyes and sneezing attacks. "They are associated with a loss of quality of life, as many allergy sufferers also suffer from sleep disorders, a drop in performance at work and school and restrictions on leisure activities during the pollen season," he explained.

The "supposedly harmless allergic rhinitis" can also trigger allergic asthma. To avoid this, early diagnosis and treatment is necessary. "If symptoms occur at around the same time every year and last for several weeks, a pollen allergy could be the cause," says Horak. Then you should see a doctor.

Immunotherapy can bring relief
Those affected can reduce their exposure by using pollen screens and air purifiers in their homes. "Above all, they should avoid the pollen as much as possible," said Horak. The symptoms are alleviated by special active ingredients (antihistamines and cortisone). There is also allergen-specific immunotherapy (AIT), in which the immune system learns to tolerate the allergy triggers over a period of several years. "Around 70 to 80 percent of those treated report an improvement in symptoms," reported the doctor. The earlier immunotherapy is started, the better the chances of this happening.