Natural radionuclides in the rocks of the Valle del Cervo Pluton in Piedmont.

Monitoring of the gamma radiation in Valle del Cervo Pluton was performed by determining U and Th contents in the main rock types cropping out over the entire area and pertaining to the granitic complex, syenitic complex and monzonitic complex. In particular, syenitic rocks were largely used as building and ornamental materials (e.g. Sienite della Balma). All the samples are fresh and do not present joints or fractures filled with U minerals. In the crushed samples the activity of uranium varies from 346 to 764 Bq/kg. Concentration of thorium varies from 202 to 478 Bq/kg. For all the analysed rocks uranium activity is higher than thorium one. The lowest value of radioactive concentration is referred to rocks of the granitic complex. The most active rocks are syenites. The data confirm the high activities of Valle del Cervo rock types, strongly connected with high K content of the source magma (geochemical signature); on the contrary, the activity seems to be not related to the location of the samples.

Radon-prone areas in the Lombard plain.

This paper reports the results of indoor radon measurements carried out in the Lombard plain. The aim of this study, which is based on the geological context, was to identify radon high-risk areas. The underlying geology has been established by means of the available stratigraphies giving a schematic representation of the sites in which either occurrence of gravel or silt and clay predominate with depths ranging from 0 to 50 m. Radon measurements were performed in a sample of 411 one-family houses in seven villages located in the southern area of Bergamo and Brescia. The findings indicate that when the substrate is dominated by clay, radon concentration for dwellings on the ground floor are low, whereas a strong predominance of underlying gravel mixed up in sand gives in winter months high radon flux from underground.

Characterization of the Danube River sediments using the PMF multivariate approach.

Chemical composition data for the Danube River and its tributaries sediments were analyzed using positive matrix factorization (PMF). The objective was to identify both natural and anthropogenic sources affecting Danube Basin. During the Joint Danube Survey 2 (JDS2) campaign 148 bottom sediments samples were collected. The following elements were analyzed using the X-ray fluorescence technique: Al, As, Ca, Cd, Cl, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Si, Ti, V and Zn. Mercury was determined by cold vapour atomic absorption spectrometry. Three factors were obtained considering the whole dataset (Danube and tributaries), identified as: (i) carbonate component characterized by Ca and Mg; (ii) alumino-silicate component dominated by Si and Al content and the presence of some metals attributed to natural processes; (iii) anthropogenic source identified by Hg, S, P and some heavy metals load. To better characterize the role of tributaries, the Danube and tributaries datasets, were also analyzed separately. The same three factor structures were identified in the Danube dataset. For the tributaries, a four-factor source model gave one further factor dominated by S and P, which could be attributed to the use of fertilizers in agriculture.