Origin of Arsenic Pollution in Southwest Tuscany: Comparison of Fluvial Sediments

Abstract

The Colline Metallifere in SW Tuscany are characterized by strong anomalies in arsenic concentrations and distribution. The area is sparsely populated and largely wild, though it has been subject to human impact due to mining and metal processing since Etruscan and Roman times. In the Middle Ages it was exploited intensively for silver and copper. Until 1995, pyrite (FeS2) was mined and roasted to produce sulphuric acid and iron. Hypotheses based on geological and mineralogical factors formulated in the last 20 years have failed to explain the peculiar distribution of arsenic in the Colline Metallifere. Here we report preliminary results of widespread sampling and analysis of the fluvial sediments of rivers originating in this mining area. The data was analysed in relation to the archaeological features of the area, since the presence of ancient mining and ore processing sites can shed light on the peculiar distribution of arsenic. Comparison of data from two rivers and their respective contaminated and uncontaminated coastal lagoons also clarified the general mechanisms of arsenic mobility, pinpointing the source of arsenic contamination. The study methods also promise to be useful for discovering unknown archaeological sites.

Arsenic concentration in the soils of the Brenta Plain (Northern Italy): Mapping the probability of exceeding contamination thresholds

“…Other factors are soil texture and soil organic matter content (Chen et al, 2002). Literature data suggest an average value of 20 mg kg − 1 for Italian soils (range 1.8-60 mg kg − 1 , Yan-Chu, 1994), but widespread hot spots occur in volcanic and mining areas (Costagliola et al, 2004;Donati et al, 2005).…”

Arsenic pollution in the southwest of Tuscany: monitoring of Cornia catchment basin

“…From Figure 7 it is evident that the behaviour of [As] is completely different for the three rivers. Pecora and Bruna shows opposite trends and the highest [As] values are located in correspondence with ancient and modern anthropogenic activities [5,6]. On the Contrary, Cornia River, which flows in a less industrialized area, always presents low arsenic levels.…”

“…In previous papers [5,6] we described the results of an extensive sampling of fluvial sediments collected from two very similar rivers and their tributaries, which flow almost parallel from the "Colline Metallifere" towards the coastal wetlands: the Pecora River and the Bruna River. From a comparative study of these two environments we were able to establish the extent of Arsenic natural background.…”

“…The present paper is a part of a wider project that has been started in order to understand the origin of the strong Arsenic contamination in the Scarlino plain in the southwest of Tuscany [3][4][5][6]. In this area, a partially filled wetland, close to the sea, a power plant for sulfuric acid production from pyrite roasting was installed in 1962.…”

Arsenite-oxidizing bacteria isolated from arsenic contaminated surface and ground water of Uttar Pradesh, India

“…state to aquesous state through geologic and anthropogenic activities (Aiuppa et al, 2006). As (III) pollutes fresh waters due to arsenic contaminated waste derived from industrial process as well as use of As compounds in agriculture (Oremland and Stolz, 2003;Donati et al, 2005). As pollution causes a serious health related problems (Ahmed et al, 2010).…”