Pollen may contain twice as much allergens in the future

In Finland, the pollen season lasts for six months, from February to September. For the country’s more than one million people with pollen allergies, the season can be a struggle and may, in a worst-case scenario, result in incapacity for work.

“Pollen may contain twice as much allergens in the future, due to the combined effect of higher temperatures and higher levels of carbon dioxide,” says Marjut Roponen, Professor of Toxicology of Environmental Exposures.

“At the Department of Environmental and Biological Sciences, we are currently exploring the predicted pollen climate of Turku in 2100, as the most radical changes will be seen in Southern Finland.”

“The current forecasts issued by the University of Turku indicate how much pollen is in the air and where it is travelling. In the future, people with allergies may benefit from more detailed information on the intensity and allergen content of the pollen in the air,” Roponen says.

Respiratory model for pollen experiments

At the Department of Environmental and Biological Sciences, growth chambers mimicking summer conditions have been used for growing timothy grass and meadow foxtail under current and future climate conditions. Pollen from these grasses is used in exposure experiments.

“We had to wait for the exact moment when the pollen is emitted from the flowers. We collected it into paper bags by shaking the flower heads,” Doctoral Researcher Tarleena Tossavainen explains.

In the laboratory, small tissue culture platforms known as inserts are used to cultivate cells obtained from the nose and lungs of both non-allergic and allergic individuals. The cells contain cilia and mucus, and they behave similarly to respiratory organs or lungs – just in miniature size.

The cell samples are exposed to regular pollen and to “super pollen”.

“In the inserts, we are studying, e.g., epithelium permeability, cell damage and cell health, as well as their metabolic activity,” Postdoctoral Researcher Maria Martikainen says.

“We are also exploring cell inflammation, isolating RNA and analysing gene expression on a broad scale. This paints us a very clear picture of the future effects pollen may have on the respiratory system.”

Pollen history can be combined with past health records

Next autumn, the clinical part of the study will be completed at Kuopio University Hospital. The conventional skin prick test will be used to analyse reactions to pollen in both healthy and allergic individuals.

“Together with Research Director Eila Kankaanpää of the Department of Health and Social Management we will also consider the economic implications,” Roponen says.

Changes taking place in Finland’s pollen history can also be seen in health records.

“Project Researcher Miisa Kankaanpää is analysing health records from the 1970s against weather data from the Finnish Meteorological Institute, and against pollen data from the University of Turku. The study shows clear trends in allergy diagnoses.”

When all these data are combined, it is possible to model the change in the prevalence of allergies as well as health care costs associated with these diseases. This type of information will help society prepare for changes.

However, some things about the future remain uncertain.

 “For instance, we are yet to see whether thunderstorm asthma will occur in Finland. Thunderstorm asthma is a phenomenon where exposure to small pollen particles increases significantly due to atmospheric pressure, humidity and wind. As a result, people with allergic asthma may need to be treated in a hospital more often,” Roponen says.