The number of allergy sufferers is increasing worldwide. More people struggle with pollen in cities than in the countryside. A research team wants to find out what could be causing this and is taking a very close look at birch pollen.
Air pollution could contribute to birch pollen becoming more allergenic. Researchers at the University of Kraków found this out in a study. The results of the study, which were published in the journal “Plos One”, provide clues as to why more people suffer from pollen allergies in urban areas than in rural areas. The substances that trigger allergies are called allergens.
To find out if and how air pollution can change the nature of tree pollen, the research team led by Monika Ziemianin from the Department of Clinical and Environmental Allergology at the Faculty of Medicine collected samples of unopened birch blossoms from seven different locations with different levels of air pollution, including three locations in the Big city of Krakow, three different small towns and out of the woods.
The samples were then examined. The blossoms were opened in the laboratory and the pollen inside was examined using a special method. The researchers paid particular attention to the protein called Bet v1, which is considered the main allergen in birch pollen. When comparing Bet v1 concentrations, the research team found that they were higher in the urban samples with high levels of air pollution compared to the small town and forest samples. They conclude that air pollution may be a reason more people develop allergies and that treatment for sufferers with birch pollen allergies often fails.
The scientists also measured a number of other values ??that should provide information about the general condition of the birch trees, Betula pendula. They found that changes in pollen proteins are not directly related to the physiological state of the plant, which was assessed based on the efficiency of photosynthesis and the pigment composition of the leaves. From their results, they concluded that when planning green spaces in cities, care should be taken to ensure that no more allergenic trees are used. The reason: despite the ability of the trees to adapt to the environment with high concentrations of air pollution, the trees then produce more stress proteins that have a higher allergenic potential.
“Birches are the most allergenic trees in cool and temperate climates, and their pollen is a trigger of allergic rhinitis and asthma in 10 to 30 percent of the population. Because of their attractive appearance and relative tolerance to environmental factors, birches have historically also been commonly planted in urban areas planted in residential areas,” says Dr. Stefanie Gilles, Head of the Department of Environmental Immunology at the University of Augsburg, the Science Media Center.
Gilles considers the results of the current study to be understandable. “This result corresponds to expectations insofar as studies on the connections between pollen allergenicity and anthropogenic pollutants in ragweed have already been published,” explains Gilles. At the same time, the expert criticizes the structure of the study, that the values ??for environmental pollution were not collected directly at the locations where the samples were taken.
