Radon For Homeowners and Residents

Take me back to the ICRP's Guide to Radon!

Exposure to Radon at Home

It’s important to measure the radon in your home, and to take simple steps if you find that it is high. Radon in homes originates from the soil and rock surrounding it, and sometimes from building materials.

Often, the pressure indoors is lower than the pressure in the soil, which naturally draws soil gas into the home.

Other factors influencing radon levels in the home include: the soil composition and radon concentration, the area of the building in contact with the ground, the air-tightness of the building, the floor level and size of rooms, and lifestyle choices like opening windows and doors.

Typical Radon Levels

Typically, the average radon concentration in outdoor air is around 10 Bq/m³, although it be as low as 1 Bq/m³ in some places and higher than 100 Bq/m³ in others.

Indoors, average radon concentrations are usually higher, averaging around 50 Bq/m³, with some places less than 10 Bq/m³ and others 10,000 Bq/m³ or more.

Governments usually set reference levels for indoor radon in the 100-300 Bq/m³ range

The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) is the leading international body on radiation levels and effects. Visit the UNSCEAR website or read the UNEP report on "Radiation Effects and Sources" based on UNSCEAR work to learn more

Quotes from Publication

Publication 126 paragraph 22-25

While the radon concentration from soil to outdoor air is diluted rapidly, this is not the case if the flux enters closed premises such as dwellings … there is a pressure differential between the soil and the foundations of the building. This causes an enhanced flow of radon-rich soil air...

The transfer of radon from the soil to buildings depends on several parameters:

• the composition of the soil (chemistry, geology, soil moisture, and permeability to radon);
• the concentration of radon in the soil;
• the difference in pressure between inside and outside of the considered building or location, between the soil and the atmosphere surrounding the building, and between the soil and the lower rooms of the building;
• the area of building in contact with the ground; and
• the air tightness of the outer shell of the building, including the presence of cracks, pipe ducts, cable ducts, etc., especially in the floors and foundations of the building.

The transfer of radon within buildings also depends on several factors:

• the circulation of air in the building depending on ventilation and air conditioning;
• the meteorological and seasonal parameters, mainly the temperature difference between outside and inside air;
• the floor level and the size of the rooms; and
• the lifestyle choices, such as opening doors and windows, and the working habits of the building occupants.

Radon can be released from building materials into the surrounding air. … However, in the majority of cases, this source of radon is of secondary importance…

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Measuring and Reducing Radon Levels in your Home

Measuring radon in your home is easy!

You can find a radon test kit at a local hardware store or online. Radon levels are different in different parts of your home, so put the small device in a room where people spend a lot of time. When the measurement is done, mail it back to the supplier, and they will send you the results. The cost should be no more than the equivalent of a few tens of dollars or Euros. You can also hire a professional.

A long-term measurement is preferred, ideally for three months or more. Radon levels change during the day and from season to season, making shorter measurements less reliable.

The level of radon in your home should be compared to your national reference level, usually set somewhere in the range 100 to 300 Bq/m³.

From the WHO Factsheet on Indoor Radon:

“Well-tested, durable and cost-efficient methods exist for preventing radon in new houses and reducing radon in existing dwellings.”

“Radon levels in existing homes can be reduced by:

• increasing under-floor ventilation;
• installing a radon sump system in the basement or under a solid floor;
• avoiding the passage of radon from the basement into living rooms;
• sealing floors and walls; and
• improving the ventilation of the house.”

Hiring a professional to reduce radon levels in your home will normally cost the equivalent of several hundred dollars or Euros, or more.

Quotes from Publications

Radon Protection Strategy: Publication 126 paragraphs 41-45

…Prevention of radon exposure is most relevant in new buildings. The implementation of preventive measures in new and renovated buildings provides a good partial solution… This also helps to develop awareness amongst professionals involved in the construction sector.

Remediation in existing buildings is also often appropriate in buildings with high radon concentrations. In such situations, there may be a primary source of radon ingress, and radon levels can often be reduced by a factor exceeding 10. … the aim should be to reduce both the overall risk for the population and, for the sake of equity, the highest individual exposures to levels that are as low as reasonably achievable…

…The radon protection strategy should be properly scaled, with other health hazards and priorities identified in the country taken into account. Furthermore, comparison and integration between the radon protection strategy and other public health policies, such as non-smoking and indoor air quality policies, should be sought in order to avoid inconsistencies and achieve better effectiveness.

Considering the ubiquity of radon exposure, and the multiplicity and diversity of situations and decision makers, a straightforward, realistic, and integrated radon protection strategy, addressing most situations with the same approach, is appropriate. It must be supported and implemented on a long-term, potentially permanent basis, and involve all the relevant stakeholders. '

National reference Level: Publication 126 paragraphs 84, 76, and 86

The first step is to characterise the exposure situation of individuals and the general population in the country, as well as other relevant economic and societal criteria, and the practicability of mitigating or preventing the exposure. … Many factors such as mean radon concentration and radon distribution, number of existing homes with high radon levels, etc. should be taken into consideration.

… The Commission strongly encourages … a national derived reference level that is as low as reasonably achievable in the range of 100–300 Bqm-3…

The value of the national derived reference level for radon exposure should be reviewed periodically to ensure that it remains appropriate.

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Take me back to the ICRP's Guide to Radon!

More In-Depth Information

If you are looking for something more extensive look no further below are a collection of related links and articles that can provide more information on this topic!

Expert Summary of ICRP Recommendations on Radon	ICRP Radon Summary
Lung Cancer Risk from Radon and Progeny and Statement on Radon	ICRP Publication 115
Radiological Protection against Radon Exposure	ICRP Publication 126
WHO Factsheet on Indoor Radon	www.who.int
WHO Handbook on Indoor Radon	Handbook
UNEP report on Radiation Effects and Sources	https://wedocs.unep.org/

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