Radon

Under the Health and Safety at Work etc 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.

Employers are required by the Management of Health and Safety Regulations at Work 1999, to assess risks from radon in workplaces in radon affected areas, and this usually requires a measurement. The Ionising Radiations Regulations 1999 require action to protect employees if the average radon gas concentration exceeds 400 Bq m-3.

Risks of radon

Radon is a radioactive gas which occurs naturally. It has no taste, smell or colour. Special devices are needed to measure it.

Radon comes out of the ground. Outdoors, it is diluted to very low levels. However, in some cases the radon level indoors can build up to high concentrations. In such cases, it does pose a serious risk to health.

Radon is the second largest cause of lung cancer - the first is smoking. People who are exposed to high levels of radon are more likely to get lung cancer (much more so if they are smokers as well). It is estimated that radon causes 1,000 - 2,000 lung cancer deaths per year.

Radon is a naturally occurring radioactive gas that 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 are also found in ground floor 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.

Radon (more properly known as radon-222) comes from uranium which occurs naturally in many rocks and soils. Since granite contains relatively high levels of uranium many people think that it is only granite areas of the UK, such as the South West of England, that have high radon levels. This is untrue and, as shown on the map above, many parts of the country have high radon levels.

Most radon gas breathed in is immediately exhaled and presents little radiological hazard. However, the decay products of radon (radon daughters) behave more like solid materials than a gas and are themselves radioactive.

These solid decay ducts attach to atmospheric dust and water droplets which can then be breathed in and become lodged in the lungs and airways. Some decay products emit particularly hazardous radiation called alpha particles which cause significant damage to the sensitive cells in the lung.

Radon is now recognised to be the second largest cause of lung cancer in the UK after smoking. Lung cancer is also the biggest cause of cancer related death in the UK and only 5% of all lung cancers are curable.

Radon contributes by far the largest component of background radiation dose received by the UK population and, while the largest radon doses arise in domestic dwellings (due to the longer time spent there), significant exposures are possible in workplaces. Epidemiological studies on occupational groups with known high exposure to radon show a significantly increased risk of lung cancer. A recent study which pooled the results of 13 European case-control epidemiological studies of people exposed to radon at home (Darby et al, 2005) has confirmed the risks and refined their accuracy. It also showed that the risk from radon is approximately 25 times higher for cigarette smokers than for non-smokers.

Although the radon data used in production of the indicative atlas above comes from measurements in homes, the maps indicate the likely extent of the local radon hazard in all buildings. The information in this atlas is therefore relevant to employers in assessing workplace risks. Under the Health and Safety at Work etc 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. For ground floor and underground workplaces this risk assessment should include radon measurements.

Risk assessment for radon should be carried out in relation to:

• all underground workplaces in the UK; and
• all workplaces located in radon Affected Areas.

Pentland are able to offer Radon Risk Assessments and Surveys on many types of building. To requst a survey or for more information on the services we can provide, please contact us on 01925 284 351 or email info@pentlandgp.co.uk.