City dwellers more likely to suffer from hay fever, study shows
Birch trees in towns and cities produce around twice as much pollen as those in the countryside, said Peter Schmid-Grendelmeier from the University of Zurich.
KEYSTONE
Zurich researchers say they were able to detect a sharp increase in antihistamine levels in wastewater just a few hours after an episode of pollen. They also explain why urban dwellers are more likely to suffer from hay fever than those in the countryside.
Antihistamine enters wastewater via urine, said Peter Schmid-Grendelmeier from the University of Zurich in an interview with the NeueZürcher Zeitung on Saturday. The results of his study, conducted along with the Swiss Federal Institute of Aquatic Science and Technology (Eawag), have not yet been published.
Researchers also noticed the increase in antihistamines at an unusual time: “alder and hazel trees were not yet pollinating, while birch pollen was not yet measurable”, Schmid-Grendelmeier said.
According to the dermatology professor, it hasn’t yet been possible to explain what triggered an allergy in many people at that time. “There may be a tree species that we haven’t yet had on the radar,” he said.
The study also shows a gap between urban and rural areas when it comes to hay fever, with city dwellers more exposed – partly due to “more aggressive” pollens.
“For example, birch trees that grow in towns contain around twice as many allergens as birch trees in the countryside,” Schmid-Grendelmeier said. The protein responsible for sparking the allergy is a “stress” protein, and tees exposed to too much exhaust fumes, for example, produce more of it, he said.
Exhaust fumes and traffic-related pollutants can also irritate the mucous membranes in humans, which further explains why city-dwellers are more at risk.
Desensitisation
During an allergic reaction, the body releases a chemical mediator – histamine – which then causes symptoms such as a runny nose or red eyes. Antihistamines block the histamine receptors in the body, said Schmid-Grendelmeier.
In severe cases, pollen can also cause breathing difficulties. In such instances patients are advised to see a doctor for desensitisation treatment, which aims to “switch the immune system from hypersensitivity to tolerance,” the expert added.
The next opportunity to start such a treatment will be in autumn – before the next pollen season.
Adapted from French by DeepL/dos
This news story has been written and carefully fact-checked by an external editorial team. At SWI swissinfo.ch we select the most relevant news for an international audience and use automatic translation tools such as DeepL to translate it into English. Providing you with automatically translated news gives us the time to write more in-depth articles.
If you want to know more about how we work, have a look here, and if you have feedback on this news story please write to english@swissinfo.ch.
External Content
Your subscription could not be saved. Please try again.
Almost finished… We need to confirm your email address. To complete the subscription process, please click the link in the email we just sent you.
Popular Stories
More
Life & Aging
Zurich: how the world capital of housing shortages is tackling the problem
In Switzerland more people are being referred to electrical therapies or psychedelic-assisted psychotherapy. Are there similar approaches where you live?
Lufthansa set to abolish in-flight sales, SWISS to keep them
This content was published on
Perfumes, cigarettes, sunglasses: The German airline Lufthansa will no longer sell these products on long-haul flights in future. Lufthansa subsidiary Swiss is sticking to in-flight sales for the time being.
This content was published on
After a short break due to the cool weather, grass pollen is now flying in Switzerland, the Swiss Allergy Centre said on Monday.
This content was published on
Researchers have shown for the first time in Switzerland that urban greenery measurably reduces the stress levels of city dwellers.
US tariffs affect canton Zurich less than other locations
This content was published on
The Zurich cantonal government is observing the developments surrounding the US tariffs "with concern". Compared to other locations, however, Zurich should get off lightly.
This content was published on
The Alpine Museum in Bern is showing the finds of diver David Godio, who has been fishing lost objects out of the River Aare for years.
This content was published on
Healthcare costs in Switzerland rose by 2.4% in 2023. The Swiss healthcare system thus cost around CHF94 billion ($113 billion).
Karaoke tram to run through Basel during Eurovision
This content was published on
A karaoke tram will be doing the rounds in Basel during the Eurovision Song Contest (ESC). During a 90-minute journey, guests can sing and dance for free in a vintage car.
Net wealth of Swiss households rises to CHF4.8 trillion
This content was published on
Private household assets in Switzerland continued to grow strongly in 2024. The increase was driven by both the growth in financial assets and higher property assets.
You can find an overview of ongoing debates with our journalists here . Please join us!
If you want to start a conversation about a topic raised in this article or want to report factual errors, email us at english@swissinfo.ch.