Methodology

Computer-Assisted Personal Interviews (CAPI) were conducted in Bulgaria using a stratified random sampling approach, ensuring national representativeness across key demographic variables: gender, age, and level of urbanization, based on the total population distribution. A multi-stage clustered sampling design was employed. The sample was stratified by region and type of residence (urban/rural), with Primary Sampling Units (PSUs) defined as enumeration areas (e.g., electoral districts). Within each PSU, households were selected using a random route (random walk) method, and individual respondents within households were identified using the last-birthday selection method.

The data collection period began with a soft launch on December 23, 2022, followed by the main fieldwork conducted from January 3 to January 22, 2023. The final sample comprised N = 1,009 respondents. The questionnaire was developed collaboratively by RadoNorm and the National Center of Radiobiology and Radiation Protection (NCRRP) in Bulgaria, which also partially funded the data collection. Data were collected by the Bulgarian research firm Market Links. Data were analysed by SCK CEN, Belgium.   Data are available at:  [DOI:10.20348/STOREDB/1179/1299]