Technical support Quick guide to radon in council premises
What is radon?
Radon (more properly known as radon-222) is a naturally occurring radioactive gas that can seep out of the ground and build up in indoor workplaces. Radon comes from uranium which occurs naturally in many rocks and soils.
You can't see, smell, hear or feel it. Most radon will disperse harmlessly into the outdoor air but some will pass from the ground and collect in spaces under or within buildings. Radon concentration levels are measured in units called becquerels per cubic metre (Bq/m3).
For workplaces, action must be taken to manage occupational exposure if the radon level exceeds 400 Bq/m3.
What are the health hazards associated with radon?
Radon is recognised to be the second largest cause of lung cancer in the UK after smoking, resulting in up to 2000 fatal cancers per year. Lung cancer is the biggest cause of cancer related deaths in the UK with only 5% of lung cancers being curable.
Which workplaces may be affected?
The highest levels are usually found in underground spaces such as cellars, basements, caves and mines. Well ventilated ground floor and higher storeys are unlikely to have significant radon levels. Boiler and plant rooms located at basement level aren't generally considered to be ‘at risk’ workplaces as they're not usually occupied by employees on a permanent basis.
What are the radon levels in Shropshire?
The Health Protection Agency publishes data and graphs indicating radon levels in the UK. The average level in Shropshire is 50 Bq/m3, with higher levels being found in the Shrewsbury town area.
What are the legal requirements for workplaces?
Under the Health and Safety at Work Act 1974, employers must, so far as is reasonably practicable, ensure the health and safety of employees and others who have access to their work environment.
The Management of Health and Safety at Work Regulations 1999 require the assessment of health and safety risks and this should include radon if a workplace is located underground or in a radon affected area.
The Ionising Radiations Regulations 1999 (IRR99) come into effect where radon is present above the defined action level of 400 Bq/m3 when employers are required to take action to restrict resulting exposures.
The Building Regulations 2000 (England and Wales) supported by BRE report BR211 require that buildings and extensions (workplaces and dwellings) constructed after 2000 in radon-affected areas have protective measures installed during construction.
What is a radon survey?
Radon surveys should be conducted in any workplace where its location suggests that elevated radon levels may be found and the area is to be occupied on a full-time basis by employees. Inexpensive surveys can be carried out by leaving small plastic passive detectors in workplaces of interest. Measurements are made over a period of three months after which the detectors are posted back to the supplier who then provides the report with results. Our Property Client Team will arrange for radon surveys when required.
What do the radon survey results mean?
Where workplace measurements show radon levels below 400 Bq/m3 the only further action required is to decide when the risk assessment will be reviewed. The period of remeasurement might be in the order of once every ten years.
For occupied workplaces with radon levels above 400 Bq/m3, managers may need to take steps to manage occupational exposure or ensure the radon levels are reduced by engineered means. Control measures shall be implemented when radon levels of greater than 400 Bq/m3 are recorded.