Approximately 23,000 measurements of workplace radon concentrations were conducted using the Radiation and Nuclear Safety Authority’s radon measurement boxes in 2001–2017. The readings include measurements which at least yielded a result as well as spatial data on a municipal or address level. Indoor air radon measurements at workplaces are also conducted by other operators besides the Radiation and Nuclear Safety Authority.

Indoor radon levels may vary greatly even within one postal code area. Radon concentrations are the highest in buildings located on penetrable moraines and the lowest in buildings built on compact clayey soil. In addition, the way the house is built affects the radon concentration. Workplace radon concentration must be measured:

1. in areas defined by the Radiation and Nuclear Safety Authority where more than a tenth of representative results of radon measurements is higher than the reference value for workplace radon concentration (300 Bq/m³) on the basis of earlier radon concentration data
2. on a ridge or other gravel or sandy soil with good air permeability
3. on sites that are located wholly or partly underground  
4. in an installation that distributes household water or in a food establishment the water of that does not derive solely from a body of surface water and has contact with indoor air.

Workplace radon concentration does not need to be measured:

• if no worker’s annual working hours in the space exceeds 20 hours
• if the floor and walls of the building are not in contact with the ground and the good airing of the space in between is apparent or if the workplace is located on the second or upper floor of the building.  

The radon concentration should not be higher than 300 Bq/m³ during working hours at a workplace where work is performed on a regular basis (section 19 of the Ministry of Social Affairs and Health’s Decree on Ionizing Radiation).

Find the workplace radon measurement data for your municipality or postal code area

The search results include the postal code areas or municipalities (area distribution of 2017) where at least five workplace measurements have been conducted. The results include the results of the radon box measurements in underground workplaces and regular above-ground workplaces.