The good weather is settling in, and with longer evenings and higher temperatures, spring brings a less-welcome gift: allergies.
Every year, millions of people swap sneezes from winter colds for sneezes from pollen.
When spring arrives, trees begin their annual release of pollen, starting with hazel and alder, followed by birch, ash, and oak through spring, before grasses take over in the summer.
Pollen allergy is triggered when the molecules in the air come into contact with the respiratory tract and the eyes. The immune system can then react and release histamine, which can cause inflammation, provoking dilation of the blood vessels and leading to a runny nose, watering, and stinging eyes.
The onset, duration, and intensity of the pollen season vary every year and depend on weather conditions and the physiological cycles of plants.
“Trees are natural things; they actually follow a cycle of pollen production with stronger years followed by a weak year, where they generate energy,” Astha Tiwari, a scientist in the mycology and aerobiology unit at the Belgian public health institute Sciensano, told Euronews Health.
She added that pollen production requires a lot of energy from trees, so stronger years are always followed by weaker ones.
Are pollen seasons becoming more intense?
The prevalence of pollen allergy in the European population is estimated at 40 percent, making it one of the most common allergens in the region.
A higher prevalence is observed in urban areas due to factors like pollution and lifestyle changes.
“We do see, if we look at the results from the last decade, that pollen seasons are becoming longer, they are starting a bit earlier, and the pollen intensity is increasing,” said Tiwari.
She added that this is potentially linked to climate change, as warmer temperatures are ideal for trees and plants to bloom sooner, causing their pollination period to start earlier.
A study tracking pollen data from monitoring stations across Belgium, the Netherlands, and Luxembourg between 30 and 44 years found that most tree species showed an overall increase in annual pollen levels and peak values, alongside an earlier start to the pollen season.
Rising temperatures and increased atmospheric carbon dioxide concentrations stimulate plant growth and augment pollen production, extending pollen seasons and increasing their concentrations.
People become more sensitised to an allergen the longer they are exposed to it, meaning that with more plants producing more pollen over longer periods of time, pollen-related allergies will increase.
Researchers from the University of East Anglia in England found that the number of people suffering from allergies fever from ragweed pollen could double from 33 to 77 million people by 2050.
What can you do to protect yourself?
Pollution and pollen form a vicious cycle, with each feeding the other and increasing sensitivity among people.
Air pollution, particularly nitrogen dioxide, ozone, and particulate matter, has been found to
chemically alter pollen molecules, making them more allergenic and aggressive.
Not everyone is equally sensitive to pollen, Tiwari noted. Even low pollen concentrations in the air can already induce allergy symptoms in highly sensitive persons.
Allergic reactions to pollen can impact sleep, impair mental well-being, and decrease quality of life, productivity loss, or lower school performance for children, according to the European Climate and Health Observatory.
However, there are steps people can follow to minimise exposure during peak pollen days.
One simple measure is to keep windows closed at home during the day. For ventilation, it is better to open them in the early morning or evening, when pollen concentrations in the air are lower.
Showering upon returning home and changing clothes can also reduce the amount of pollen that enters the house, and, where possible, it is better to dry clothes inside the house.
When going outside, sunglasses can help avoid particles entering the eyes. Allergens stick to the lens surface of reusable contact lenses, disposable lenses or glasses are better options.
Tiwari also said coastal areas can be beneficial for people with allergies as the sea breeze and less vegetation reduce the amount of pollen in the air.
