Since August 2004, the activity concentration of radon in premises open to the public has to be measured, in accordance with the order of 22 July 2004, by organisations approved by the Director General for Nuclear Safety and Radiation Protection. Measurement campaigns are run between 15 September of year N and 30 April of the following year. For the 2004-2005 campaign, 33 organisations were approved to carry out screening (level N1), 9 of which were approved for performance of the subsequent investigations (level N2) necessary for identifying radon transfer channels within a building.

At the request of the ASN (DGSNR circular of 20 December 2004 concerning management of the radon risk in premises open to the public), the DDASS in the 31 priority departments (see chapter 3) acted to inform the property owners of their new obligations to measure radon in teaching, health care and social institutions, spas and penitentiaries. This campaign was launched belatedly and the number of screening operations carried out remained low (a few tens) owing to the time needed to prepare the calls for bids locally.

A fresh campaign began in autumn 2005. For this campaign, 101 organisations were approved for N1 level screening, with 6 of them approved for additional N2 level investigations.

In terms of supervision, the ASN examined the approval applications submitted by the organisations and visited the head offices of several of them (5), with the support of the IRSN. This second level supervision is supplemented by a DDASS examination of the inspection reports produced by the approved organisations, whenever the activity levels measured exceed the supplementary action level of 400 Bq/m3. Owing to the small number of inspections conducted in 2004-2005, no results summary was produced.

In 2005, the list of professional activities (industries, spas and drinking water treatment plants) requiring supervision of human exposure to Naturally Occurring Radioactive Materials (NORM) was published, owing to the fact that the materials used contain natural radionuclides and are likely to generate doses that are significant from the radiation protection standpoint.

Supervision of implementation of these new measures is not yet operational, but should be broken down as follows:
– the labour inspectors and radiation protection inspectors are competent to monitor the steps taken by the head of the establishment to assess the exposure of its workers and reduce it if necessary;
– the inspectors for classified installations and the radiation protection inspectors are competent to monitor the steps taken by the operator to reduce public exposure, if necessary, whenever these industrial activities are subject to authorisation under the terms of the regulations applicable to installations classified on environmental protection grounds.

Monitoring the natural radioactivity in drinking water is now an integral part of the health monitoring activities of the DDASS. The ASN is responsible for overall coordination, jointly with the Directorate General for Health. Implementation of the new monitoring programmes has been under way (see point 1.5 of chapter 3 and point 2.4 of chapter 5) since 2004.

The ASN is preparing a circular clarifying what to do when the reference levels concerning the radiological quality of this water are exceeded.