And of the radon, what know?

Published on: 01/02/2017

The World Health Organisation (WHO) considers radon gas to be carcinogenic, in agreement with the International Agency for Research on Cancer (IARC). Inhaling this gas can cause lung cancer due to the radiation produced when it decomposes. In the United States, it is the second-ranked cause of lung cancer, after smoking.

Most radon is generated by granitic subsoils as these are rich in uranium. You must find out the what the radon level in your area is. You can consult the Radon zoning map of the Nuclear Safety Council (Consejo de Seguridad Nuclear) by municipalities.

The risk of contracting lung cancer due to radon depends on:

  • The level of radon in your home or workplace.
  • The amount of time you spend in these.
  • If you are a smoker or have been a smoker.

Radon legislation

  • Directive 2013/59/Euratom of the Council on 5 December, 2013, setting out basic safety standards for protection against the dangers arising from exposure to ionising radiation. The incorporation period expired in February 2018.

The European directive regulates so much the exhibition to radiations in the field of medicine to improve the security of patients, health workers and teams, as occupational exhibitions and poblacionales to radiations and of way expresses to the radon.

This directive establishes a limit value for radon exposure of 300 Bq/m3. In Spain, the Royal Decree 783/2001 remains in force, which approves the Regulations on Health Protection against Ionizing Radiation, and establishes a limit of 600 Bq/m3

At present, the health aspect has been implemented, but we are still waiting for the workplace and public sections on protection against radon.


  • Royal Decree 732/2019 of 20 December, modifying the Technical Building Code (Código Técnico de la Edificación; CTE), which includes measures to combat radon.

This involves the partial implementation of Council Directive 2013/59/EURATOM of 5 December, 2013.

It creates a new section, called DB-HS6, within the basic health documents where regulatory measures are set out for cases where the reference level of 300 Bq/m is exceeded3. The measures for limiting radon penetration in buildings are established according to the risk level of radon in the municipality where the building is located:

- Risk Areas I: between 300 and 600 Bq/m3

- Risk Areas II: above 600 Bq/m3

The corresponding municipalities are listed in Appendix B and the measures will be applicable to new works and interventions in existing buildings, including extensions, changes of use, or renovation. 

The Ministry of Transport, Mobility and Urban Agenda has published a guide entitled: “Rehabilitation measures against radon” (September 2020), to help to draughtsmen of works and people affected building users in the starting up of preventive measures that they appear in the CTE.