Radon is a colourless, odourless, radioactive gas, produced as a byproduct of the decay of the radioactive element Radium. Radium exists in all rocks and soils in varying quantities, but there is more in granites, shales and soils near Uranium deposits.

In the short term, Radon is no risk to health, and is harmless in itself, but it decays into a series of radioactive metals which when inhaled can lodge in lung tissue. The particles sit in the lungs and continue to emit radioactive particles, eventually causing lung cancer.

Radon can enter the home through building materials containing certain minerals, tap water, well water and domestic gas. It can also seep through cracks, drains and solid concrete. The biggest problem occurs in tightly sealed modern homes, where the concentration can be higher inside the home than outside. There is now concern that kitchens with granite work surfaces may also pose a problem.

Your Local Authority should have a list of areas likely to have a high level of Radon present in the ground. If you think you live in such an area, you can arrange to have your home tested for Radon - there are also self-test kits available, some over the internet.

There are several changes you can make to reduce the level of Radon exposure, and its effect on the human body. Firstly, if you smoke, stop, and discourage smoking in the home. The combined effects of tobacco smoke and Radon increase the risk of lung cancer. Spend less time in areas with a high concentration, such as the basement. If practical, increase the airflow into and through the house, especially the basement, and if you have a crawl space beneath your home, keep the vents on all sides open all year