Online survey for allergic people

Sciensano researchers are launching an investigation to understand how nitrogen deposition affects people with pollen allergy in Belgium.

As an allergic person, you are invited to participate in the study by answering a questionnaire (20 min maximum). For the survey to run smoothly, participants must be at least 18 years old, live in Belgium, have a pollen allergy (whether medically confirmed or not) and have symptoms of this allergy on the day of the questionnaire. People who completed the survey last year can do so again.

In brief

The birch pollen season is gradually coming to an end. Conditions are more favourable for allergic individuals, but caution remains necessary.

Other trees currently in bloom include ash, willow, oak, plane and some members of the Cupressaceae family.


Latest measure: 
Tuesday, 16 April, 2024
20232024Mean 2014 - 2023threshold value11 Mar18 Mar25 Mar01 Apr08 Apr15 Apr22 Apr29 Apr06 May13 May20 May02004006008001000120014001600180020002200grains / m³

Good to know

  • A few useful recommendations: avoid outdoor activities, wear sun glasses, do not dry linen outside, rinse your nose regularly, wash your hair before going to sleep.

  • Typical allergy symptoms such as runny nose, cough or shortness of breath (in case of asthma) can easily be mistaken for a cold, flu or coronavirus infection. However, fever and body aches should be given special attention as they might be caused by viral infection. It is recommended to call your general practitioner in case of doubt.

  • The standardized pollen detection technique allows retrospective measurement of the levels from samples taken the day before. Samples are analyzed manually during the working days by optical microscopy.