Total natural radioactivity, Veneto (Italy)

We present the first detailed map of the terrestrial natural radioactivity of the Veneto Region (Italy), a 18,264 km(2) densely populated area, previously investigated through indoor radon surveys. The activity concentration in 709 representative samples of the main Alpine lithostratigraphic units was measured by using a high-purity germanium (HPGe) gamma-ray spectrometer to characterize the radioactivity content of the 41 cartographic units of the Veneto Lithostratigraphic map at 1:250,000 scale. An area accounting for 61% of the territory, comprising alluvial plains was investigated through airborne gamma-ray measurements. The large-volume NaI detectors were mounted on an ultralight aircraft, flying a 7000 km line. The data were interpolated using Ordinary Kriging, and a distribution model of the radioactivity content was produced. The result of the data analysis is a total natural radioactivity map of Veneto at 1:250,000 scale in which the activity concentration of the territory is visualized in seven classes, according to the percentile values calculated on the total dataset of measurements.