Radon Measurement and Advice

Radon is a radioactive noble gas that originates from uranium (and thorium). The decayed atom becomes RADON. This decays further to polonium, then to bismuth and then to lead. These decay products emit alpha (cf. helium) and beta (cf. electron) particles.

NRW is not a radon precautionary area! This does not mean that we do not have radon here.

We advise and measure on site and prepare the appropriate risk assessment. 

What is radon?

Radon (Rn) is a naturally radioactive noble gas that occurs everywhere. The radioactive by-products of radon (RnFP) in particular contribute significantly to radiation exposure, as these are also inhaled and decay directly in the lungs with very short half-lives.

What risks can occur?

A higher risk of lung cancer.

Are there values to be observed for the radon indoor air concentration?

The reference value for the average annual radon-222 activity concentration in the air in occupied rooms and workplaces is 300 Bq/m³. An effective dose value of 6 mSv/a is reached if employees carry out work in the exposure area at a radon concentration of 1000 Bq/m³ - 2000 h.

What legal sources are there on radon?

 In the Radiation Protection Act in Chapter 4 Part 2 (Chapter 2) (protection against radon) with § 121 to § 132. In addition, work areas with increased radon exposure are listed in Annex 8.

When must radon exposure measurements be carried out?

Anyone responsible for an indoor workplace must arrange for measurements of the radon-222 activity concentration in the air if one (or more) of the three cases applies:

• The workplace is located on the ground floor or basement of a building that is located in a radon precautionary area. There is an obligation to take measurements within 18 months of notification of these areas.
• The type of workplace must be assigned to one of the fields of work with increased exposure to radon according to StrlSchG Annex 8. These are workplaces in underground mines, shafts and caves as well as visitor mines, in radon spas and radon healing tunnels as well as all workplaces in water extraction, treatment and distribution facilities. In these cases, the measurement must have been taken within 18 months of starting work at such a workplace.
• There is an order from the competent authority for the measurements, as there are indications that the reference value may have been exceeded. In these cases, the authority specifies a deadline by which a measurement must be carried out.

At what level are radiation protection measures required?

If the average annual radon-222 activity concentration in the air at workplaces exceeds the reference value of 300 Bq/m³, the person responsible for the workplace must immediately take measures to reduce the radon exposure.

Are radiation protection tests necessary?

If the assessment shows that the effective dose may exceed 6 millisieverts per calendar year, an examination by an authorized physician is required and a certificate issued by the authorized physician must be submitted for continued employment stating that there are no health concerns regarding employment.

When must a radiation protection officer be appointed for radon exposures?

If an assessment of the radiation exposure shows that an annual exposure of more than 6 mSv is possible, the competent authority may also require a radiation protection officer on the basis of the necessary notification in conditions. Radon map (BfS geoportal).