Traces of iodine-131 detected again in several European countries

Published on 12/03/2012 • 11:14 am

Information notice


ASN has been informed by its European counterparts of new cases of iodine-131 being detected in several countries in northern and eastern Europe. IRSN, the French Institute for Radiological Protection and Nuclear Safety, responded to the presence of this isotope in atmospheric aerosols by stepping up the frequency of its environmental radioactivity measurements to detect whether the phenomenon also affected France. The measurement results, which can be consulted on the IRSN website, revealed very low levels of iodine-131 (less than one µBq/m3) in aerosols1 in France at the beginning of February 2012.


Although such iodine-131 activity levels are unusual in France and Europe, they present no health or environmental risk.


ASN remains in close contact with its counterparts, particularly within the HERCA network (Heads of the European Radiological Protection Competent Authorities) to keep track of the situation and determine its exact causes.


A similar episode in which particulate iodine-131 (from 0.5 µBq/m3 to 10 µBq/m3) was detected in atmospheric aerosols was observed in several European countries, including France, in November 2011. That episode was traced back to the Isotope Research Institute in Budapest, which produces radioisotopes intended for medical, research and industrial applications.

1. Iodine can be found in the atmosphere as gas (gaseous iodine) or particles (particulate iodine). The first form can be trapped on activated carbon cartridges for monitoring purposes, while filters are used to trap the second form. Particulate iodine is generally detected when its activity exceeds one microbecquerel per cubic metre of air. The detection limit for gaseous iodine is several hundred µBq/m3.

Date of last update : 08/06/2017