Ilaria Guagliardi

Assessment of lead pollution in topsoils of a southern Italy area: Analysis of urban and peri-urban environment.

Exposure to lead (Pb) may affect adversely human health. Mapping soil Pb contents is essential to obtain a quantitative estimate of potential risk of Pb contamination. The main aim of this paper was to determine the soil Pb concentrations in the urban and peri-urban area of Cosenza-Rende to map their spatial distribution and assess the probability that soil Pb concentration exceeds a critical threshold that might cause concern for human health. Samples were collected at 149 locations from residual and non-residual topsoil in gardens, parks, flower-beds, and agricultural fields. Fine earth fraction of soil samples was analyzed by X-ray Fluorescence spectrometry. Stochastic images generated by the sequential Gaussian simulation were jointly combined to calculate the probability of exceeding the critical threshold that could be used to delineate the potentially risky areas. Results showed areas in which Pb concentration values were higher to the Italian regulatory values. These polluted areas were quite large and likely, they could create a significant health risk for human beings and vegetation in the near future. The results demonstrated that the proposed approach can be used to study soil contamination to produce geochemical maps, and identify hot-spot areas for soil Pb concentration.

Modelling seasonal variations of natural radioactivity in soils: A case study in southern Italy

The activity of natural radionuclides in soil has become an environmental concern for local public and national authorities because of the harmful effects of radiation exposure on human health. In this context, modelling and mapping the activity of natural radionuclides in soil is an important research topic. The study was aimed to model, in a spatial sense, the soil radioactivity in an urban and peri-urban soils area in southern Italy to analyse the seasonal influence on soil radioactivity. Measures of gamma radiation naturally emitted through the decay of radioactive isotopes (potassium, uranium and thorium) were analysed using a geostatistical approach to map the spatial distribution of soil radioactivity. The activity of three radionuclides was measured at 181 locations using a high-resolution ?-ray spectrometry. To take into account the influence of season, the measurements were carried out in summer and in winter. Activity data were analysed by using a geostatistical approach and zones of relatively high or low radioactivity were delineated. Among the main processes which influence natural radioactivity such as geology, geochemical, pedological, and ecological processes, results of this study showed a prominent control of radio-emission measurements by seasonal changes. Low natural radioactivity levels were measured in December associated with winter weather and moist soil conditions (due to high rainfall and low temperature), and higher activity values in July, when the soil was dry and no precipitations occurred.

From rock to soil: geochemical pathway of elements in Cosenza and Rende area (Calabria, southern Italy)

The parent materials slowly release the elements over time as part of the natural weathering process. As molecules of an element move between their various forms, they come to a dynamic equilibrium that shifts according to certain soil conditions, including: pH, texture, aeration of the soil, and the presence of other ions. In this study, 149 samples of topsoil (0-10 cm) were collected in the municipalities of Cosenza and Rende (Calabria, southern Italy) and analyzed for 36 elements by X-ray fluorescence spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). In addition, 18 rock samples were collected on outcrops of whole area and analyzed by ICP-ES and ICP-MS. Elemental concentrations in soil are primarily controlled by the geochemical composition of bedrock, with some notable exceptions ascribing to anthropogenic factors.

Studying potentially toxic trace elements in soil-plant system: a case study of an olive orchard in southern Italy (Calabria)

Soil to plant Transfer Factors (TFs) are commonly used to estimate the food chain transfer of chemical elements. The entry of trace contaminants, such as potentially toxic trace elements (PTEs), from soil into human food chains, is controlled by their uptake by plant roots in the long term. Some PTEs in the soil-plant system were studied through the TFs in an olive orchard in southern Italy. Soil samples and olive leaves were collected and analysed for Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn by using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). In addition, pH, electrical conductivity, organic matter, clay content and cation exchange capacity were measured in soil samples. Factor of trace elements from soil to olive plants showed average value