Radon Limits – Lung Cancer Risk
Studies have shown that breathing in Radon is the primary cause of lung cancer in those who have never smoked. The main exposure is also likely to be in the home as most time is spent here but exposure in the workplace can also occur.
The World Health Organisation (WHO) has drastically reduced the maximum amount of radon that should be permitted in buildings. The new recommended limit of radon gas is 100 becquerels per cubic metre. The WHO have stated that "radon is a significant cause of 3 to 14 percent of worldwide lung cancer cases". It is a growing public health threat and there has been a call for tougher building codes from the construction industry with mitigation programmes for existing buildings. These levels can be decreased through ventilation and other simple and inexpensive repairs to the structures of walls and floors of buildings and detected using test kits that ascertain radon levels.
Radon is a radioactive cancer causing gas that occurs naturally and can be found in rocks and soil. It seeps out of the ground and builds up in buildings. Radon arises from the natural decay of uranium and can seep into buildings. It is the decay that produces the solid product which when breathed in can become attached to the lungs cells.
The radiation from these particles can cause serious damage to the lungs and airways. The highest levels of Radon are usually detected in basements or ground floor buildings with these having a lower pressure than the surrounding atmosphere. Radon gas enters building through holes in the walls, cracks in the concrete and through drains.
Granite has one of the largest uranium contents and is therefore one of the largest sources of decaying uranium. The southwest of England has a large risk area although it does affect the remainder of the country as well.
Radon is increasingly dangerous as it is an invisible, odourless and tasteless gas and can cause cancer from low and medium doses of exposure in the workplace or home.
The Health Protection Agency has surveyed those areas with the highest radon risks and has produced a radon dataset (see link at end of page). Employers can review these lists to check if it is likely that their buildings are more likely to have a significant level of Radon within them.
The workplaces more likely to be affected can include the following:
- Underground workplaces such as basements, mines, caves and utility service ducts in any area
- In high radon areas factories, offices, shops, classrooms and care homes
- Poorly ventilated ground floor rooms
Health and Safety Legislation requires the employer to assess the health and safety risks in workplaces which should include the risk of exposure to radon. The risk varies in accordance with the area and situation of the workplace so the requirements can change from place to place. Radon surveys should be conducted if there is a risk of significant exposure with measurements taken on a regular basis. However, a risk assessment should be carried out on all below ground workplaces in the UK and all workplaces located in radon affected areas.
Controlling the levels of radon in workplaces can vary depending on the severity of the problem. During construction of a building a radon barrier can be installed within the structure. To reduce radon levels in existing buildings, ventilation of the building is required and this can be dealt with in several ways. Ventilation indoors and underground are effective as are radon sumps, sealing the walls and floors and fitting extraction pipework. If required a Radiation Protection Adviser can also be consulted to advise on the best way to reduce the levels of radon in the workplace.
The review of Radon should of course be kept under review, with re-assessments being carried out on any change to the construction of the building. The Health and Safety Executive provides guidelines to assist with this and can be found on their website.Useful links: