Elena Romano

The impact of the Bagnoli industrial site (Naples, Italy) on sea-bottom environment. Chemical and textural features of sediments and the related response of benthic foraminifera

The coastal zone of the disused industrial site of Bagnoli, has been studied since 1999 in order to highlight chemical and ecological features of pollution, mainly due to a steel plant. This further study was performed in order to check the foraminiferal response to changes in sediment grain-size and contaminant concentrations and to recognise the actual effects of the environmental stress determined by industrial pollution on the foraminiferal assemblages. This was attained by considering a wider area than in the previous studies so as to recognise the possible reference conditions. Very high contamination, mainly due to Cu, Fe, Hg, Mn, Ni, Pb, Zn and PAHs, was recorded in the marine sediments close to the steel plant. Contaminant concentrations and sediment composition were recognised as important factors influencing the foraminiferal response by means of statistical analysis. The foraminiferal abnormality index (FAI) is positively correlated with heavy metals concentration, exceeding the natural threshold in front of the plant. Furthermore, increasing pollution levels correspond to the increase of pollution-tolerant species in the assemblage.

Benthic foraminifera from the coastal zone of Baia (Naples, Italy): assemblage distribution and modification as tools for environmental characterisation.

The coastal zone of Baia (Naples) is currently included in a protected marine area, but in past it was affected by strong anthropogenic pressure for commercial harbour activity. In order to investigate the impact of past activities, a multidisciplinary characterisation was undertaken to evaluate the environmental quality of marine sediments. Thirty-six grab samples were collected for grain-size, heavy metals, PAHs and PCBs analyses. Rose Bengal stained replicates were taken for the analysis of benthic foraminifera. Chemical analyses highlighted sediment pollution mainly due to Cu, Hg, Pb, Zn, PAHs and PCBs in the northern and southern part of the study area, where some sunken vessels had been present for many decades. Modifications of foraminiferal diversity and density, and increased percentage of abnormal specimens, were considered as indicators of environmental degradation. Correlation between faunal parameters and pollutant concentrations was found by means of statistical analysis. The highest degree of environmental stress shown by foraminifera in the northern sector could be referable to the high concentrations of PCBs (up to 144 ng g(-1) d.w.).

ENVIRONMENTAL POLLUTANTS AND ORGANIC CARBON CONTENT IN SEDIMENTS FROM AN AREA OF THE MOROCCAN MEDITERRANEAN COAST

Toxicol.andEnviron.Chem., Vol. 84, No. 1–4, pp. 53–67 2001 OPA (Overseas Publishers Association) N.V.Reprints available directly from the publisher Published by license underPhotocopying permitted by license only the Gordon and Breach SciencePublishers imprint,a member of the Taylor & Francis Group.

Pollution monitoring of Bagnoli Bay (Tyrrhenian Sea, Naples, Italy), a sedimentological, chemical and ecological approach

Many studies finalised to a reclamation project of the industrial area were carried out on the industrial site of Bagnoli (Naples). Among these studies, the sedimentological, chemical, and ecological characteristics of marine sediments were analysed. Seven short cores, located in the proximity of a steel plant, were analysed for grain-size, polychlorobiphenyls, polycyclic aromatic hydrocarbons and heavy metals. As well, benthic foraminiferal assemblages were investigated. Sediment pollution was mainly due to heavy metals; in particular, copper, mercury and cadmium showed a ‘spot’ (site-specific) distribution, while iron, lead, zinc and manganese showed a diffuse distribution, with a gradual decrease of concentration from coast to open sea. Heavy metals pollution seems to explain some of the variation in the foraminiferal abundance. The combined copper and iron contamination might be the cause for the complete absence of foraminifera in the four shallower cores. Moreover, the ratio between normal and deformed specimens of Miliolinella subrotunda and Elphidium advena could be indicative of heavy metal pollution. In particular, Miliolinella subrotunda could be a potential bioindicator for copper pollution, since the abundance of irregular specimens of this species could be related to copper concentrations.

X-Ray Core Scanners as an Environmental Forensics Tool: A Case Study of Polluted Harbour Sediment (Augusta Bay, Sicily)

Since the 1970s the highly industrialised and enclosed Augusta Bay (Sicily) has become internationally recognized as a polluted environment that could represent a hazard to human health. The pollutant of greatest concern, derived from a former chlor-alkali plant, is mercury that exists beyond Intervention Levels in parts of the harbour. The affected areas are also contaminated by other heavy metals and organic compounds (PAHs and PCBs) that were mainly discharged from co-located petrochemical industries. Several previous investigations established the magnitude of particular contaminants in sediments and evaluated the impact of the pollution on a range of biota. The current study, which represented part of a larger project managed by the Italian Environmental Research Institute ISPRA, was concerned with investigating a series of cores collected across the harbour area to establish reliable pollution chronologies based on elemental and radiochronological (137Cs) profiles. The declared motivation for the main project was to acquire scientific evidence that could be used to support a legal investigation against the industries that caused the pollution and who could potentially be expected to contribute to remediation costs. Undisturbed cores were collected from the northern (mildly polluted), central (significantly polluted) and southern (strongly polluted) parts of the Bay using available bathymetric data to avoid areas affected by dredging. The study has demonstrated the value of using an automatic, X-ray sediment core scanner (Itrax) to acquire high-resolution geochemical data. The Itrax provided a non-destructive, sensitive and rapid capability to systematically analyse a broad range of major and trace elements. One of the collected cores of this study, taken from the most polluted site, provided more than 20 continuous elemental profiles with depth (e.g. Ti, S, Ca, K, Mn, Fe, Cr, V, Ba, Cu, Zn, Br, Rb, Sr, Zr, Hg, Se, Mo). The Itrax data quality were validated against a dataset acquired using a conventional WD-XRF instrument and both sets of profiles are demonstrated to be consistent. This ability of the Itrax to automatically scan cores over a significantly shorter time compared to conventional laboratory methods (days compared to weeks) confirms its potential in contributing to environmental forensic studies. Its additional ability to simultaneously record a radiographic image (and radiographic digital profile) provides a link between sediment layering (density variations linked to mineralogy) and elemental composition.

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.

Platform of integrated tools to support environmental studies and management of dredging activities

Dredging activities can cause environmental impacts due to, among other, the increase of the Suspended Solid Concentration (SSC) and their subsequent dispersion and deposition (DEP) far from the dredging point. The dynamics of the resulting dredging plume can strongly differ in spatial and temporal evolution. This evolution, for both conventional mechanical and hydraulic dredges, depends on the different mechanisms of sediment release in water column and the site-specific environmental conditions. Several numerical models are currently in use to simulate the dredging plume dynamics. Model results can be analysed to study dispersion and advection processes at different depths and distances from the dredging source. Usually, scenarios with frequent and extreme meteomarine conditions are chosen and extreme values of parameters (i.e. maximum intensity or total duration) are evaluated for environmental assessment. This paper presents a flexible, consistent and integrated methodological approach. Statistical parameters and indexes are derived from the analysis of SSC and DEP simulated time-series to numerically estimate their spatial (vertical and horizontal) and seasonal variability, thereby allowing a comparison of the effects of hydraulic and mechanical dredges. Events that exceed defined thresholds are described in term of magnitude, duration and frequency. A new integrated index combining these parameters, SSCnum, is proposed for environmental assessment. Maps representing the proposed parameters allow direct comparison of effects due to different (mechanical and hydraulic) dredges at progressive distances from the dredging zone. Results can contribute towards identification and assessment of the potential environmental effects of a proposed dredging project. A suitable evaluation of alternative technical choices, appropriate mitigation, management and monitoring measure is allowed in this framework. Environmental Risk Assessment and Decision Support Systems (DSS) may take advantage of the proposed tool. The approach is applied to a hypothetical dredging project in the Augusta Harbour (Eastern coast of Sicily Island-Italy).