Allergy sufferers beware: air pollution can make birch pollen allergenic

Birch pollen from places with high air pollution may be more allergenic than birch pollen from areas with clean air, according to a new study. However, according to the assessment of independent researchers, the data from the study are not sufficient to conclusively prove this claim – measures in cities are still appropriate.

The researchers used birch trees to investigate to what extent air pollution changes the quality of tree pollen, according to the research in the journal ‘Plos One’. They collected birch blossoms from seven different locations in the city of Krakow, in small towns and in the forest and examined them in the laboratory.

The researchers found a higher concentration of the allergen “Bet v1” in the samples from the more polluted sites. Their conclusion: birch pollen is more allergenic when air pollution is higher.

actually is however, the role of air pollution is not entirely clear according to the assessment of non-participating researchers. Environmental epidemiologist Marloes Eeftens of the Science Media Center’s Swiss Tropical Institute says:

The differences can also be explained by other factors, such as different levels of dryness. There are also natural fluctuations and the maturity of the tree plays a major role. The number of samples collected is also too small for such a study.

Nevertheless, according to Eeftens, it must be considered in urban planning whether it is wise to plant allergenic tree species in densely populated areas. It has been proven that a higher percentage of people with allergies live in cities with polluted air than in areas with clean air. “Regardless of whether they become allergenic in the presence of air pollutants or not. A birch will always release some of the allergens. I would recommend not planting too many birch trees,” says Eeftens.

(jam/sda)