Radon is an inert, radioactive gas, whose most common isotope is radon 222, found in uranium 238’s decay chain. The parent isotope before radon 222 is radium 226. Radon decays with a half-life of 3.8 days, i.e. for a given amount of radon, only half remains after this time. When radon decays, a chain of new elements is formed, “radon daughters”, which are also unstable. When radon and some of the “daughters” decay, alpha radiation is emitted. This radiation is composed of helium nuclei that can cause harm to human tissues.

No, radon is odourless and tasteless. In addition, radon is an inert gas, which means that it does not react with other substances. The only way to check radon gas levels in air and water is therefore to perform measuring operations.

Radon is formed naturally in the soil and then rises and passes through the ground surface. Radon gas normally dissipates quickly into the atmosphere and therefore does not represent a danger to health. But when radon penetrates into enclosed spaces such as residences or mines, radon can reach high levels and represent health risks to those present. The extent of health risks depends on exposure i.e. on radon levels and exposure time to such levels, in addition to the fact that a combination of long-term exposure to radon and tobacco smoke increases such risks. The Swedish Radiation Safety Authority (SSM) estimates that approx. 500 people die of lung and tracheal cancer caused by radon each year in Sweden. The average risk to Swedes is therefore greater than the risk of dying in a traffic accident.

The easiest and least expensive thing to do is to measure radon using track film detectors.

Track film detectors consist of a track film and a little transparent plastic piece, inside a plastic capsule that is an electrical conductor. Radon is an inert gas, which is not the case of radon daughters, so radon gas can enter a detector by means of diffusion while radon daughters cannot. Radon gas inside the detector decays and emits alpha particles (helium nuclei). Some of the alpha particles come into contact with the film (plastic piece) cause mechanical damage to the surface layer, a so-called track. When measuring is completed, the films are processed in a warm lye solution for a few hours, which causes the tracks to become big enough to be identified under a microscope. The tracks are counted using an image analysis programme and the radon level can be calculated based on the number of tracks and exposure time. The entire system is calibrated by comparing results with films sent to the Swedish Radiation Safety Authority (SSM) to be exposed to known radon levels.

Long-term measuring (can give an annual average value, recognized by the authorities) must span over at least 60 days during the heating period (1 October - 30 April). Short-term measuring (only an indicative measurement, not recognized by the authorities), must span over at least 7 days (longer measuring periods give more accurate measurement values).

It sure can! The highest radon levels in housing is caused by radon that rises up from the ground. When there is negative pressure in housing, ground radon can be sucked in; negative pressure is created, among other ways, when the temperature is higher indoors than outdoors, which is assumed to be the situation during the heating period (middle of October to middle of April). Ground radon can come from natural soil or from filling material under housing. It can be dissipated by the air that comes in through cracks and/or holes in the foundation slab or basement walls. Housing with a suspended foundation (crawl space) can, in certain meteorological conditions, be subject to very high radon levels due to incoming leaks of air from spaces under the housing.

You should start by having a radon survey done where appropriate measures are proposed to you. For further advice and help, you can contact the environmental agency in your municipality or visit Svensk Radonförening’s (the Swedish Radon Association’s) website.it is important to remember that radon problems can normally be prevented/treated.

You should consider that radon levels in your dwelling can change following renovation work. New ventilation or replacing windows can affect radon levels. Over the years, small cracks in housing foundations can appear, through which radon can easily pass from the ground. You shouldn’t wait longer than 10 years before measuring again.

At present, there are no government contributions to prevent/treat radon problems.

For new constructions, it can be worth knowing if the development land emits a lot of ground radon, as radon protection can be built in from the start. In some cases, the municipality’s local planning committee demand a survey of radon levels in the ground before granting a building permit. Ground radon measurement you order here.