Radon

Radon is a naturally occurring radioactive gas that is colorless and odorless. Its presence in the environment is common, both outdoors and indoors. However, prolonged exposure to radon inside buildings poses a significant risk to public health.

Inhalation of radon is the primary source of ionizing radiation exposure for the general population, contributing over 40% to the annual effective dose of radiation received. The percentage of the annual dose received by the global population can be found in the report "Sources and Effects of Ionizing Radiation, UNSCEAR 2008 Report, Vol. I."

Exposure and Health Effects
Prolonged exposure to radon indoors is one of the leading causes of lung cancer. Smokers and ex-smokers are at an increased risk due to the combined action of tobacco and radon. There is no consistent evidence linking radon exposure to other types of cancer or diseases.

Radon produces radioactive particles in the air we breathe. These particles become trapped in our respiratory pathways, where they emit radiation, causing damage to the lungs. This damage increases the risk of lung cancer with prolonged exposure over time.

According to the World Health Organization (WHO), it is estimated that radon exposure causes between 3% and 14% of lung cancer cases globally. In Europe, it is estimated that 9% of lung cancer deaths are attributed to radon exposure, representing about 2% of all cancer-related deaths.

Radon is present everywhere, both outdoors and indoors in buildings. All buildings contain radon, and in most cases, the concentrations are low.

In Portugal, certain areas of the country are more prone to higher levels of radon in buildings. These areas can be consulted on the radon susceptibility map. The map, produced from a national survey and the national radon monitoring campaign, indicates the level of susceptibility to radon indoors. However, the only way to know the exact radon concentration is by direct measurement.

Radon Presence and Monitoring
Although radon is present both outdoors and indoors in buildings, its concentration can vary significantly. Most buildings have low concentrations, but there are specific geographic areas where radon levels may be higher.

The only way to determine the exact radon concentration in a building is through direct measurements.

Mitigation of Radon Exposure
Reducing exposure to radon indoors can be achieved through preventive measures implemented during the construction phase of new buildings or through corrective or remediation measures in existing buildings.