The Ionising Radiation Regulations 1999, also apply to work with natural radiation, including work in which people are exposed to naturally occurring radon gas and its decay products.
So what is radon?
Radon is the second leading cause of lung cancer in the UK. Radon Gas is a naturally occurring radioactive gas that can seep out of the ground and build up in houses and indoor workplaces. Radon is a gas produced from the decay of the elements uranium, thorium, and radium in rocks and soil ,naturally occurring element in the earth’s crust. Radon is radioactive, emitting harmful alpha radiation when it decays.
Radon is present in outdoor and indoor air, usually in small amounts. We breathe it in and out all the time. If a radon atom decays while inside our lungs, the alpha radiation released may damage lung cells. This has the potential to cause lung cancer. It is estimated that circa 2000 people die prematurely every year from radon exposure, just in England and Wales, it is estimated that over 360 of these deaths are caused to radon in the workplace.
Radon gets into buildings through a variety of routes, including directly through floors or walls in contact with soil or through the water or gas supply. It can also enter the building through the materials used within the structure.
Where is it?
Radon is known to be associated with rocks and soils which include granite and shale. The probability of encountering high radon levels has been mapped for the UK in the ‘Indicative Radon Atlas’. Shaded parts of the radon atlas are classed as ‘Radon Affected Areas’. It is important to remember that the ‘Radon Atlas’ is indicative; the only way to know if radon is present is to test for it. Studies have shown that the importation of contaminated rocks in to the sub-base of buildings are a major factor in the contribution to radon gas. 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 subsoil underneath buildings to enter through cracks and gaps in the floor. All workplaces including factories, offices, shops, classrooms, nursing homes, residential care homes and health centres can be affected. Whilst employers who only occupy parts of buildings from the first floor and above are unlikely to have significant radon levels, employers who use cellars, basements and poorly ventilated ground floor rooms are far more likely to have problems with radon levels.
Properties with basements are also at increased risk, regardless of geographic location, as the basement has several surface areas in contact with the ground through which the gas can permeate.
There are no types of indoor ground floor workplace in which the radon can assumed always to be low because of ventilation or working conditions. It is not, however, generally necessary to measure above the ground floor. The number of monitors required for each building depends on the workplace type and use.
Radioactive particles from radon can damage cells that line the lungs and lead to lung cancer.