People who work in poorly ventilated tunnels, mines or basements affected by radon gas are at serious risk. This odourless gas is generated by the radioactive decay of uranium, which occurs in rock and soil. It is the second commonest cause of lung cancer in the UK.
Radon gas is radioactive – when radon starts to decay, radioactive elements are produced. These attach to dust particles to form solids. When inhaled, these solids become trapped in the lungs, where the radiation damages the cells. The risk is dependent on the level of the radon gas and the period of exposure.
High-risk occupations include utility tunnel workers, mine workers, rail and subway workers, construction excavators and power plant workers. Radon levels above 400Bq/m3 (becquerels per cubic metre of air) require immediate attention to establish proper ventilation.
The most effective way to control radon gas is to channel fresh air into a workspace to ensure that radon doesn't leak into it. In tunnels, air is forced from one end to the other to dilute the radon gas to a safe level. An expert site assessment is needed to identify the required ventilation measures.
For more information on how to address and control radon gas, download our full white paper.
A radon survey is carried out when the location and characteristics of a site show that there is a risk of high levels of radon. Regular testing of radon levels is vital to ensure the safety of workers.