Review of international normatives for natural radioactivity determination in building materials

Natural radioactivity is the main source of radiation which affects the human body [1]. Anthropogenic activities (e.g. high-altitude fl ights, mining and living in buildings) have increased the exposure to these sources [2]. In particular, the problem of natural radioactivity in buildings is of great interest since the building materials are of terrestrial origin and they consequently contain small, not negligible, amounts of naturally occurring radionuclides: the radioactive isotope of potassium, 40K, and radionuclides belonging to the 238U and 232Th decay chains [3]. The building materials containing radionuclides occurring in the natural environment are called naturally occurring radioactive material (NORM) [4]. The raw materials extracted primarily for building purposes, granites (igneous rock) and the Italian tuff (pyroclastic rock) show very high radioactivity content [3]. For example, the mean specifi c activity of 40K, 238U and 232Th in red granite and volcanic tuff are, respectively, 1600, 150, 360 Bq/kg and 1900, 280, 270 Bq/kg [5], while the earth’s crust averaged concentrations are, respectively, 400, 40 and 40 Bq/kg [6]. Furthermore, the demand of large quantities of inexpensive raw materials for cost reduction and environmental sustainability purposes has led to the recycling of industrial wastes, thus enhancing the Review of international normatives for natural radioactivity determination in building materials Eros Mossini, Elena Macerata, Marco Giola, Mario Mariani