Search

Campi Flegrei is an active volcanic field in south Italy where the potentially toxic elements (PTEs) are of growing concern because the intensive anthropogenic and volcanic activities might pose adverse human health effects. In this article, 394 topsoils (0-15 cm) are collected for instrumental analysis of the2 mm fraction. The geochemical maps indicate that higher concentrations of Pb, Zn, Cd, Cr, Hg, Ni and Sb are related to the urban area, but greater levels of As, Tl, Co, Cu, Se and V are observed in the other parts. A robust principal component analysis detected: (1) the Pb-Zn-Hg-Cd-Sb-Cr-Ni association that probably highlights anthropogenic activities such as heavy traffic load and fossil fuel combustion in the urbanized area; (2) the Al-Fe-Mn-Ti-Tl-V-Co-As-U-Th association that mostly reveals the contribution of pyroclastic deposits; and (3) the Na-K-B association that feasibly indicates the weathering degree. The probabilistic health risk modeling for the children under 6 years old shows negligible Pb and Zn non-carcinogenic risk and unexpected Pb carcinogenic risk for exposure through soil ingestion. However, for the inhalation pathway, the children aged1 year old have the highest chance (90%) of acceptable (i.e. between 1E-6 and 1E-4) Pb carcinogenic health risk. This should not be overlooked because Naples is under high environmental pressure and previous studies reported the increased Pb and Zn quantities in soil over a 26-year timespan. Overall, the results of geostatistical interpolation, compositional data analysis and probabilistic health risk modeling potentially uncover the link between soil geochemistry and human health.

An empirical method was applied to estimate the 222Rn fluxes distribution across the Campania region (Italy) by using both gamma-rays and U, Th, K concentrations in soils. As a first step, K, Th and U soil concentrations and 4 K, 238U and 232Th activity have been converted into their own specific activity to calculate the Terrestrial Gamma Dose Rate (TGDR). This latter has been then used to determine the 222Rn fluxes across the region. Regardless of the radiometric or geochemical origin, 222Rn fluxes reached, as expected, their maximum values in correspondence with the volcanic centres of Campania (Mt. Somma-Vesuvius, Phlegrean Fields, Mt. Roccamonfina). However, comparing the results obtained from the two different datasets, it was also possible to infer the existence of contributions to surficial 222Rn fluxes proceeding from both some underlying geological bodies and active seismogenic sources. In line with some national regulations, the 222Rn flux esteemed from gamma radiations was also used to assess the possible regional distribution of risk deriving from the indoor environmental exposure to 222Rn; results were compared with standardized incidence rates (SIRs) of lung cancer for an area on the south-western sector of Mt. Somma-Vesuvius showing a potential spatial relationship among flux data and SIRs.