For the last two weeks the levels of birch pollen in the Swedish air has been high but towards the end of next week it will begin to fall in most places, according to Agneta Ekebom, a pollen expert at the Swedish Museum of Natural History (Naturhistoriska riksmuseet) in Stockholm.
“Flowering has reached Sundsvall. It’s hard to say how far the blooming will advance now considering that it’s getting cooler again,” she said.
After the wave of birch pollen comes the oak. Blossoming has already taken hold in southern Sweden and will soon reach the Mälar region. Many people who are allergic to birch also react to oak and beech.
Trees are coming into flower unusually early due to the warm spring weather. Last year the pollen season began later, but then exploded causing enormous problems for hayfever sufferers.
“In Stockholm we had eight days in a row with very high levels of birch pollen last year. We haven’t been near those levels this year,” said Agneta Ekebom.
Hazel and alder trees have more or less finished blooming but soon it will be time for grass pollen. In the far southern reaches of Sweden there are already early signs but levels are still low. The worst time for those allergic to grass pollen is the end of May.
The palynological laboratory at the museum, which studies the science of pollen and spores, has already been contacted by scores of people wondering when the hayfever season will strike.
Pollution makes hayfever worse for city-dwellers, despite the fact that the actual pollen levels are highest in the country, according to Agneta Ekebom.
In a normal year, almost two million Swedes are affected when the alder, hazel and birch trees come into bloom. Sales of anti-allergy tablets and nasal spray at the country’s pharmacy chain, Apoteket, increased by 27 percent last year compared to the year before.
“I don’t have any exact figures but sales have so far been higher this year compared to the same period last year,” said Carina Altsjö at Apoteket.
“That’s partly because it has been warmer this year, and partly because people want to be better prepared,” she added.