To obtain information on exposure to ionising radiation and UV radiation in the selected children, we are sending questionnaires to their families. The complete questionnaire is sent only once during the winter season 2018/19. However, a small section of the questionnaire addressing outdoor activities and sun exposure will be sent to the same families again in spring and summer 2019 to obtain information on how children’s exposure changes with the seasons. Only parents responding to the initial questionnaire will be sent the follow-up questions in spring and summer.The questionnaire includes the following aspects:

The questionnaire asks for information on the following aspects:

  • Residential history: The addresses of all places of residence of your child since birth and of the mother during pregnancy. Natural background radiation depends strongly on place of residence. The residential history of a child, will help us estimate the child’s total dose received since birth and also before being born.
  • Daily mobility: The addresses of locations where your child regularly spends time away from home. This will help us estimate how much of children’s received dose comes from other locations and how far away these locations are from home. This information is needed to assess the errors of exposure models that are based only on the home address.
  • Flight travels: Radiation exposure is increased during flight travels because cosmic radiation is more intense at higher altitudes. This information will allow us to estimate the contribution of flight travels to children’s radiation exposure. You can estimate doses received during an individual flight using online calculators, e.g.
  • Building materials of your dwelling: Building materials affect radiation exposure inside a house in two ways. First they shield off some of the radiation coming from outside. Second, building materials contain small quantities of radioactive materials. This information will allow us to explore effects of building materials on indoor radiation exposure.
  • Time spent indoors and outdoors: As mentioned, radiation exposure can be different in a house compared to outside the house. Information on time spent indoors and outdoors allows us to estimate total doses received during a typical day more accurately. As time spent outside changes throughout the year, we will ask you to provide this information again in spring and in summer 2019.
  • Food consumption: Most of the food and beverages we consume contain traces of radioactive elements. Certain foods, such as seafood, wild mushrooms or wild boar,  may have a higher content of radionuclides. This information will allow us to assess whether there are regional differences in the consumption of these foods.
  • X-rays and CT scans: These procedures generate artificial ionising radiation that are delivered to the body in low doses. We need this information to assess the contribution to total doses from these sources.
  • UV exposure: The main source of UV radiation is exposure to sunlight. Some exposure to UV radiation is essential for the body to produce vitamin D. UV exposure is also a known risk factor for skin cancer and has been hypothesized to affect our risk for other cancers. This information will help us understand how behaviours that affect exposure to UV radiation vary between children and between regions.
  • Demographic and socioeconomic information: This information will allow us to assess the representativeness of our survey and to investigate how exposure varies according to family characteristics.

You can download the questionnaire in the different languages here:

Main questionnaire:





Follow-up questionnaire:

Follow-up – DE

Follow-up – FR

Follow-up – IT