Preface "Radon, health and natural hazards II"

The radioactive noble gas radon-222, characterised by a halflifeof approximately 3.8 days, is produced by the alpha disintegrationof radium-226 in the uranium-238 decay chain.Radon, released from rocks and soils to the atmosphere, isan important health hazard (Darby et al., 2004), and an importanttracer of geophysical processes (Tanner, 1964), ableto reveal meaningful information to reduce natural hazards,including volcanic eruptions and earthquakes (Laiolo et al.,2012; Neri et al., 2011; Plastino et al., 2011; Gillmore et al.,2010).The session NH8.3 Radon, Health and Natural Hazards atthe 2010 European Geosciences Union (EGU) General Assemblyprovided a vivid illustration that understanding radonin natural and man-made environments remains the subjectof applied and fundamental research. This special issue isdedicated to results presented at this EGU session and marksthe second year of the UNESCO IGCP Project 571 “Radon,Health and Natural Hazards”.