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RADON MONITORING AT THE JOINT RESEARCH CENTRE – ISPRA

S. Verdelocco, D. Walker, P. Turkowsky, and C. Osimani
Joint Research Centre – Ispra, Radiation Protection Unit, Via E. Fermi, 21020 Ispra (Va), Italy
Tel: 00390332786299 Fax: 00390332785184 email: david.walker@jrc.org

The object of this study is to measure radon concentrations, both in the soil and buildings of the JRC
Ispra, in order to compile a radon map indicating areas with low, medium and high concentrations.
The monitoring is being performed following the recommendations for the implementation of Title
VII of the European Basic Safety Standards Directive (BSS) concerning significant increase in
exposure due to natural radiation sources. For measuring radon both passive and active methods are
being used. The passive method is a passive track detector in Karlsruhe beakers. The active instrument
used for indoor measurements is a portable radon monitor “Alphaguard PQ2000”. The study is
divided into two parts: soil air measurements and indoor measurements. For soil air measurements a
geological study of the area was performed in order to identify measurement sites and understand the
relationship between radon emission and soil type. A thick layer of alluvial and glacial deposits covers
the JRC area with more than 100 meters thickness in some sites. 38 measurement sites were chosen to
cover the whole area. The measurements commenced in August 1998 and will be completed after one
year to take into account seasonal variations, which are critical especially for outdoor measurements.
The mean concentration measured so far for every site is less than 10000 Bq/m³. For indoor
measurements monitoring in many buildings is being performed both with active and with passive
methods. The mean concentration measured, with the active monitor, for all buildings is less than 50
Bq/m³ in both old and new constructions.
The results so far obtained indicate that the JRC territory is not a radon prone area. The thickness,
composition and low permeability of superficial deposits may be the reason for low radon
concentrations in this area.