Immission control; radon measurements

• Radon is a radioactive, colorless, odorless and tasteless noble gas that occurs everywhere in the environment, albeit in varying concentrations from region to region.
• The noble gas radon can also enter the interior of buildings from the ground and accumulate in the air.
• Radioactive radiation is released when radon decays.
• Radon can be particularly hazardous to health if the air is ventilated too infrequently. If the radon concentration in the building increases, the risk of lung cancer for users and residents also rises significantly.

Section 126 of the German Radiation Protection Act (StrlSchG) sets a reference value of 300 Becquerel/m³. If this value is exceeded in work and recreation rooms, measures must be taken to reduce radiation exposure.

Since April 2020, the Office for Environmental Protection and Energy Issues has carried out voluntary long-term measurements in cooperation with the Office for Building Management in order to assess radon exposure in enclosed spaces in the city and, if necessary, to take protective measures for the population and employees.

These measurements were carried out using passive radon detectors. These are small plastic containers that do not require electricity and emit neither light nor noise. Inside these small plastic containers is a special film that is easily damaged by the radioactive decay of radon. This damage is analyzed in the laboratory after the measurement in order to determine the radon concentration. This type of radon determination is called the nuclear trace method.

During the 2020/2021 measurement period, 2-3 passive radon measuring devices (core trace method) were installed in the basement and on the first floor of 27 municipal buildings for 12 months in common rooms and storage rooms. At the end of the one-year measurement period, the devices were evaluated at the Karlsruhe Institute of Technology (KIT).

No exceedances of the reference value of 300 Becquerel per cubic meter were measured in work or recreation rooms. No legal measures are required to reduce the radon concentration.

The Office for Environmental Protection and Energy Issues recommends regular ventilation of cellar rooms to minimize radon exposure.

You want to know more?

Radon protection in buildings - State Office for the Environment

Information about radon - Federal Office for Radiation Protection