Radon testing at Highland Council properties

Passive radon detectors
Examples of passive radon detectors


The next phase of The Highland Council’s on-going programme to check its properties for levels of naturally occurring radon gas is to take place in 34 schools throughout the region commencing in December 2014.

The programme is risk based, with previous testing focused on housing and schools considered to be in higher risk areas. The next phase of testing is based on schools where there is a lower probability of radon gas being present, and includes:


  • Farr Primary & Secondary (Sutherland); 
  • Durness Primary;
  • Mount Pleasant Primary;
  • Crossroads Primary;
  • Lybster Primary;
  • Reay Primary;
  • Bower Primary;
  • Golspie High;
  • Avoch Primary;
  • Black Isle Education Centre;
  • Culbokie Primary School (PPP);
  • Raasay Primary;
  • Banavie Primary;
  • Lochyside RC Primary;
  • Lochaber High;
  • Balnain Primary;
  • Farr Primary School (Inverness);
  • Foyers Primary;
  • Kirkhill Primary;
  • Daviot Primary;
  • Milton of Leys Primary;
  • Abernethy Primary;
  • Carrbridge Primary;
  • Gergask Primary;
  • Kingussie Primary;
  • Grantown Grammar;
  • Kingussie High;
  • Grantown Primary;
  • Newtonmore Primary;
  • Glencoe Primary;
  • Inverlochy Primary;
  • St Brides Primary;
  • Strontian Community Complex & Primary
  • Ardgour Primary.


Head Teachers and Responsible Premises Officers have been notified and are briefing staff and parents on the programme of testing.

Radon Affected Areas

Radon is a naturally occurring radioactive gas. You cannot see, hear, feel or taste it. It comes from the tiny amounts of uranium that occur naturally in all rocks and soils.  This can seep out of the ground and build up in houses and indoor workplaces. The highest levels are usually found in underground spaces such as basements, caves and mines. High concentrations can also be found in the ground floor of buildings because they are usually at slightly lower pressure than the surrounding atmosphere; this allows radon from the sub-soil underneath buildings to enter through cracks and gaps in the floor.

The UK has been extensively surveyed by the Public Health England (PHE) and British Geological Survey. The highest Radon areas have been defined by Government as Radon Affected Areas and employers and householders may consult the definitive radon dataset at http://www.ukradon.org/services/address_search to see if their premises are located in one of these Areas. An area map for Scotland is available on the PHE website.

Radon contributes by far the largest component of background radiation dose received by the UK population. Each individual breathes it in throughout their lives and geological conditions in certain areas, including some parts of the Highlands, can lead to higher than average exposure levels. While the largest radon doses arise in domestic dwellings (due to the longer time spent there), significant exposures could also be possible in workplaces.

Highland Council workplace properties

All workplaces including offices, classrooms, residential care homes, hostels, depots and visitor centres could be affected if located in a Radon Affected Area.

PHE recommends that action should be taken to reduce radon levels in workplaces where the radon concentration is measured at or above the Action Level of 400 Becquerels per cubic metre (Bq/m³).

In September 2013 the Council introduced a programme to test non-domestic workplace properties in Highland which are located in areas deemed to be at the highest risk from radon gas. This initial phase concentrated on properties that were deemed to have a 3% - 100% probability of radon gas being present above 200 Bqm³, based on the radon maps. Highland is one of 16 local authorities in Scotland which has areas with a presence of radon exceeding the level which requires action to remedy the problem.

This next phase of testing will focus on properties that are deemed to have a 1%- 3% probability of radon gas being present above 200 Bqm³and will be provided to around 34 workplace properties located in Radon Affected Areas in Highland.

Where possible, disruption will be kept to a minimum but given the geographical spread and travelling times involved it is unlikely that the placing of the monitors can be done outwith normal school hours so some access may be required during normal class times.

Testing for Radon

Testing for radon is a straightforward process. The Council’s Development and Infrastructure Service will arrange for small passive detectors to be placed in various confined spaces within the property for a period of three months after which they will be sent to a validated laboratory for analysis.

What happens next?

Where low levels of radon exist (less than 400 Bq/m³), no further action will be required, although the property will be re-tested within a period of ten years or if any significant works are undertaken to the property which may affect the ventilation levels within the property, or pressure differential between the internal and external environments.

Where radon levels are found to be above the action level (above 400 Bq/m³), steps will be taken to reduce the level, normally by increasing the ventilation under a suspended floor or sucking out the radon from under a solid floor, using a fan. Development and Infrastructure Officers, in consultation with each property Responsible Premises Officer, will examine the results of the testing and the construction detail of the property to decide on the most appropriate remedial measures to take. Remedial works to properties will be arranged by Development and Infrastructure (except in the case of PPP facilities) and any management actions required within the property will be arranged by the property Responsible Premises Officer.

Further Information

Members of the public with queries about Radon, or the health effects associated with Radon can contact Public Health England, or phone PHE on 01235 822 622 during normal office hours, or visit their website.

A list of frequently asked questions has also been provided.

Radon - frequently asked questions

1.          What is radon?

Radon is a naturally occurring radioactive gas. It is produced by the decay of uranium that is present in all rocks and soils. In open air, it disperses very quickly, but can accumulate to high levels in buildings. The amount in the indoor air depends on the local geology and the building design, heating, ventilation and use. Radon is present in all buildings, including homes, so we all breathe it in throughout our lives. For most UK residents, radon accounts for about half of their total annual radiation dose. The average level in UK homes is 20 Becquerels per cubic metre of indoor air (Bq/m3).

2.          What are the health effects of radon?

Radon is present in all air. Everyone breathes radon in every day, usually at very low levels. However, exposure to high levels of radon increases the risk of developing lung cancer. There is no evidence that exposure to radon increases the risk of other cancers and exposure to radon does not cause short term health effects such as shortness of breath, coughing, headaches or fever, or long term chest conditions such as asthma, emphysema or chronic obstructive lung disease.

Significant long term exposure to high levels of radon can increase the risk of lung cancer. Of the 33,000 deaths from lung cancer every year in the UK, between 1,000 and 2,000 deaths are related to radon; however the majority of these are in smokers and ex-smokers. The risk of lung cancer is highest for people who smoke tobacco and have high radon exposures. If you smoke tobacco, quitting is the most effective way of reducing the risk of lung cancer. The risk of lung cancer from exposure to radon in lifetime non-smokers is small and many times lower than the risk of lung cancer if you smoke tobacco.

3.          What is the definition of ‘significant long-term exposure’ to radon?

Everyone is exposed to radon throughout their lifetime – it is unavoidable (exposure is the combination of the radon level and the duration).  With radon we think of exposure duration in terms of many years, usually decades.  Hence the action levels are set at radon concentrations where measures are justified to control radon exposure and reduce the risk of adverse health effects, assuming that people would be exposed to it over the long term. 

4.          What are radon ‘action’ levels’?

Radiation protection standards in workplaces are set by the Ionising Radiations Regulations 1999, which apply if radon levels are above 400 Bq/m3. If levels exceed this concentration, action should be taken to reduce radiation exposure to staff and other occupants.  Usually this is done by lowering the radon level. There is no way to eliminate all radon from the world. However, by putting in place some minor building work the levels can be reduced below the action level so that the risk becomes very small.

5.          Are children more at risk from radon than adults?

There is no evidence that radon exposure during childhood causes a greater risk than that during adulthood. Action levels for radon in homes, and also for workplaces (including schools), take into account that exposure could take place over many years. The action levels are set accordingly.

6.          How do you know where to test for radon?

The UK's primary experts on radiation protection, Public Health England (PHE) publish radon maps for the UK. These identify areas with a higher probability of radon concentration exceeding the radon action level.  The maps for Scotland are available here http://www.ukradon.org/information/ukmaps

7.          Why are schools monitored for radon?

As the Highlands are identified as having radon-affected areas the Council, like other employers, is required to monitor its premises for radon and act accordingly if levels are found to be above the action level. The Council has developed a monitoring programme. Radon tests were carried out at 13 properties over the required three month period in 2013. The results were analysed and, in the case of five facilities, have prompted the need for remedial measures to be put in place. The mitigation works have led to a significant reduction in the recorded radon gas levels at these facilities.

8.          How was the radon level measured?

Radon levels can vary between adjacent buildings and even in a room, radon levels can vary from day to day and hour to hour. Because of these fluctuations, radon levels are normally measured over a three month period with the use of small plastic detectors.

9.          If radon is found at high level, what are the risks to children who have attended this school for many years?

The increased risk to pupils, caused by exposure to radon at school, is very low. It is especially important that older pupils do not smoke since this is harmful to health in itself and increases the risks from radon exposure.

10. If radon is found at high level, what are the risks to staff who have worked in the school for many years are they at risk of getting lung cancer?

The risk of staff members developing lung cancer from radon exposure during the time they have worked at school is very small. The risk is higher in those who also smoke, so for smokers the most effective way of reducing the risk further is by stopping smoking. The remedial work which will be carried out will limit exposure to radon in the future for staff members working in the school.

11.       What about the rest of the community?

All employers and landlords are obliged to check if their properties are at risk. A first step is to check radon maps available at the website http://www.ukradon.org/. They may also need to carry out testing which can be simply arranged through the same website at minimal cost (around £25 for a radon detector).

Householders are encouraged to check the maps available at the website http://www.ukradon.org/. The http://www.ukradon.org/ website also offers a detailed map check on individual properties for around £4. If the house is in an area at risk from radon then monitoring should be carried out. This can be simply arranged through the same website at minimal cost (around £50 for a radon test pack).

12.       When will the next update be issued?

An update will be issued to all schools once further monitoring results are received.

General information about radon and health risks can be found at http://www.ukradon.org/

27 Nov 2014