Radon is a colourless, odourless, radioactive gas. It is a by-product of the decay of uranium that is naturally present in rocks and soils. Radon, being radioactive, has the potential to be harmful to living tissues. Even though it is found everywhere, in most places it is present in negligible amounts and so not harmful to health. In the air, radon decapitates harmlessly but in some buildings it can accumulate at dangerously high levels. The degree to which the building suffers from radon problems depends on the type of soil underneath the floor, the structural quality of the building and local weather conditions. Small cracks and gaps in the building’s construction can cause radon to seep into the building. Because it is odourless and colourless it is easy to ignore. We are all exposed from radon from natural and man-made sources.
Radon is the second largest cause of lung cancer after smoking. Most people who get lung cancer are smokers or ex-smokers. The combination of nicotine and high radon exposure is a lethal mix that can seriously increase the risk of lung cancer. The average amount of radon in UK homes is 20 Bq m-3. For levels below 100 Bq m-3, there is a negligible risk and no need for concern. Inside the lungs, radon can continue to emit alpha particles which are absorbed by the tissues and can cause localised cell damage. Employers, under the Radiological Protection Act 1991 and the Safety Health and Welfare Act 1989, are required to test the work place radon level and take remedial action where necessary. The Ionising Radiations Regulations 1999 are relevant where the radon is present above 400 Bq/m3. Employers are required to take action; this is enforced by local authorities.
The ground is the main source of radon. There are measures that can be taken to decrease its prevalence. If a building has a solid floor, the inclusion of a radon sump with a fan under the floor may help. For suspended floors, natural ventilation under the floor or mechanical under floor ventilation my help. The costs depend on the complexity of the building. To test for radon levels in the home, there are home test kits available to buy online. If the test comes back with a negligible result there is no cause for concern.
The UK has been extensively surveyed by the Health Protection Agency which has produced resultant maps of the approximate locations of radon throughout the UK. This indicative atlas, which although doesn’t show exact radon levels, is an approximation which should be consulted by employers and those in the building trade. Together with consulting this map, workplaces above ground should include radon measurements. For below ground workplaces, such as mines, caves and utility services, there may be extra levels of radon present, in comparison to the overground areas of the same areas.