Radon is a radioactive gas that is part of the uranium decay chain and is used, among other things is present in the bedrock, soils, groundwater and in some building materials (so-called bluestone).

Radon is invisible, odorless and tasteless. The only way to detect radon is by measuring

During the burning season, which is between October 1 and April 30.

A radon test should last at least two months. The longer the time, the more accurate the radon measurement.

Radon meters should be placed in the dwelling to be representative of radon levels throughout the dwelling. For single-storey houses, at least two measurement points should be measured – bedrooms and another room, such as a living room. In multi-storey dwellings, measurement shall be performed on each floor of living space.

Radon meters should be placed so that the conditions around the meter are as close as possible to those of the occupants, which means that the meter must not be placed close to the floor, ceiling or wall but freely in the room (for example, hanging about 25 cm down from a ceiling lamp).

The minimum legal requirement and reference level is 200 ^Bq/m3. All values below the regulatory requirement are considered acceptable. However, you should always optimize the lowest possible value. Exposure should be as low as possible and reasonable taking into account social and economic factors. However, if stricter requirements have been agreed, e.g. Miljöbyggnad assessment criteria: Gold or Silver, values are below 60 Bq/m3^resp. 100 Bq/m3^approved .

You should carry out a new radon test at regular intervals. It is recommended that a new measurement is carried out if more than 10 years have passed since the last measurement and/or there has been a major renovation or refurbishment of the building.

Yes, and this in accordance with Chapter 3. Section 6 of the Radiation Protection Ordinance (2018:506):

The reference level for radon is 200 becquerels per cubic meter of air indoors in dwellings, premises to which the public has access and workplaces, expressed as an annual average activity concentration.

A short-term measurement can only be used for advisory purposes, for example after a measure and when buying or selling a home. Short-term measurement should only be used when there is no time for a normal measurement (long-term measurement).

The results of an advisory short-term measurement cannot be used as a basis for official decisions. In order for the municipality’s environmental and health protection administration to be able to decide on an injunction. The same applies to the application for a radon grant.

A short-term measurement should be carried out in the same way as a long-term measurement, i.e. it should take place during the burning season.

A radioactive substance is a substance containing atomic nuclei that can decay spontaneously, i.e. without external influence, while emitting ionizing radiation. Gamma radiation is ionizing radiation of photons, also called photon radiation. Ionizing radiation refers to particles/photons of such high energy that they can cause ionization, i.e. knock out electrons from atoms/molecules. Radiation is the transfer of energy in the form of electromagnetic waves. Gamma radiation is the most penetrating form of radiation associated with radioactivity. The unit of measurement for radioactivity is the Becquerel [1 Bq].

Gamma radiation can be measured using a Geiger counter. A Geiger counter is an instrument that can measure radioactivity. Gamma radiation is measured in microsieverts per hour, µSv/h.

The minimum requirement and reference level for external exposure to gamma radiation from building materials is by law 1 millisievert annual effective dose. This is provided for in Chapter 3. Section 7 of the Radiation Protection Ordinance (2018:506).