The marine sedimentary record of natural and anthropogenic contribution from the Sulcis-Iglesiente mining district (Sardinia, Italy).

Intensive exploitation of base metal deposits in the Sulcis-Iglesiente district (Sardinia, Italy), lasted from the 1850s to the 1990s, determined a high environmental impact on the coastal area, but the effects on marine environment have never been investigated. A marine sediment core, dated with 14C, was characterized for grain size, chemical and mineralogical composition, in order to reconstruct the sedimentary history of the area and to assess the environmental impact of mining. The comparison of chemical and mineralogical characteristics of recent sediments with those of pre-industrial age allowed discriminating the real anthropogenic impact from the natural metal enrichment. The correspondence, in the upper core, of anthropogenic trace metal enrichment with the presence of mine waste minerals is attributed to the exploiting over industrial scale; the still high metal enrichment in sediment surface levels suggests a still existing impact due to mine dumps and tailings weathering.

Evolution of the anthropogenic impact in the Augusta Harbor (Eastern Sicily, Italy) in the last decades: benthic foraminifera as indicators of environmental status.

The study of benthic foraminifera in sediment cores provides the opportunity to recognize environmental changes, including those due to the anthropogenic impact. The integration of these data with chemical-physical parameters provides a comprehensive quality assessment. This research was applied to a sediment core collected in the Augusta bay, where a very large commercial and military harbor and one of the largest petrochemical poles in Europe are present. Inside the petrochemical area also operated, from 1958 to 2003, a chlor-alkali plant with mercury cell technology which caused anthropic contamination of surrounding land and marine areas. The sediment core was collected in front of this plant and characterized for grain size and pollutants directly associated to chlor-alkali activity, such as mercury (Hg), barium (Ba), polychlorobiphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Composition of foraminiferal assemblages and faunal parameters such as specific diversity, faunal density, abundance of abnormal specimens, and foraminiferal size were investigated as potential indicators of environmental status. Statistical analysis indicated a main common origin for Hg, Ba, and PCBs and the influence of pollutants on species distribution and faunal diversity and density. Exceptionally high Hg concentrations (63-680 mg/kg d.w.) were recorded in the whole core, where the geochronological study attributed the most contaminated levels to the period of maximum activity of the chlor-alkali plant, while a decrease of contamination was recorded after the stop of the activity. Distinct foraminiferal assemblages identified different ecozones along the core, which suggested decreasing anthropogenic impact from the bottom to the top.

Marine sediment contamination of an industrial site at Port of Bagnoli, Gulf of Naples, Southern Italy.

For almost one century an important steel plant has been active at the Bagnoli industrial area (Naples, Southern Italy). The environmental survey of near shore and offshore sediments has been carried out as fundamental part of a clean up project. The characteristics of the area, supposed type of pollution, national and international protocols in force were taken into consideration in designing sampling schemes and selecting analytical parameters. For this work, sediment grain size, PAHs, PCBs, trace elements, total hydrocarbons and organic matter were considered. Factor analysis evidenced two main types of pollution in the proximity of the industrial plant, both probably attributable to the activity of the industrial site. The first one, due to Cd, Pb, Zn and Mn seems determined by localised activities at the southern part of the plant. The second one, due to Fe and Mn, appears directly linked to the whole contaminated area.