A geo-chemo-mechanical study of a highly polluted marine system (Taranto, Italy) for the enhancement of the conceptual site model.

The paper presents the results of the analysis of the geo-chemo-mechanical data gathered through an innovative multidisciplinary investigation campaign in the Mar Piccolo basin, a heavily polluted marine bay aside the town of Taranto (Southern Italy). The basin is part of an area declared at high environmental risk by the Italian government. The cutting-edge approach to the environmental characterization of the site was promoted by the Special Commissioner for urgent measures of reclamation, environmental improvements and redevelopment of Taranto and involved experts from several research fields, who cooperated to gather a new insight into the origin, distribution, mobility and fate of the contaminants within the basin. The investigation campaign was designed to implement advanced research methodologies and testing strategies. Differently from traditional investigation campaigns, aimed solely at the assessment of the contamination state within sediments lying in the top layers, the new campaign provided an interpretation of the geo-chemo-mechanical properties and state of the sediments forming the deposit at the seafloor. The integrated, multidisciplinary and holistic approach, that considered geotechnical engineering, electrical and electronical engineering, geological, sedimentological, mineralogical, hydraulic engineering, hydrological, chemical, geochemical, biological fields, supported a comprehensive understanding of the influence of the contamination on the hydro-mechanical properties of the sediments, which need to be accounted for in the selection and design of the risk mitigation measures. The findings of the research represent the input ingredients of the conceptual model of the site, premise to model the evolutionary contamination scenarios within the basin, of guidance for the environmental risk management. The study testifies the importance of the cooperative approach among researchers of different fields to fulfil the interpretation of complex polluted eco-systems.

Mercury and methylmercury contamination in Mytilus galloprovincialis from Taranto Gulf (Ionian Sea, Southern Italy): risk evaluation for consumers.

Total mercury (THg) and methylmercury (Me-Hg) concentrations were determined in mussels (Mytilus galloprovincialis) from 10 stations located in the Mar Piccolo of Taranto (Ionian Sea, Taranto Gulf) an important semi-enclosed basin in Italy, devoted to mussel culture activities. The obtained results show that THg and Me-Hg concentrations ranged from 0.236 to 0.559 µg g(-1) d.w. and from 0.066 to 0.155 µg g(-1) d.w., respectively. Consequently, the Me-Hg/THg ratios ranged from 17% to 49%. The dietary intake of THg and Me-Hg were studied among children and adults from Taranto (Southern Italy). The estimated weekly intake for THg and Me-Hg was below the Provisional Tolerable Weekly Intake (PTWI) established by European Food Safety Autority (EFSA) for all sampled mussels, though their consumption provides a THg intake in children near the PTWI.

Sedimentary humic substances in the northern Adriatic sea (Mediterranean sea).

Humic compounds were determined in sediments collected in an area of the Adriatic sea receiving fresh waters from the river Po. Sediment cores (10 cm) were sectioned into four layers which were analysed separately for redox potential (Eh), total phosphorus (TP), total organic carbon (TOC), humic (HA) and fulvic acid (FA) content. The structure of HA and FA was also investigated. The results showed that the TOC and TP content decreased from the coast to the open-sea stations. Humic and fulvic acid concentrations were also inversely correlated to the distance from the coast. Moreover, the humic and fulvic acids were closely correlated to the total organic content and to the total phosphorus content. The correlations found between humic substances (HS) and TOC and TP, respectively, could be explained both by an in situ formation due to the high content of nutrients and organic matter, and by a common source of HS, TOC and TP, namely the River Po discharge. The predominant presence of aliphatic carbon in the humic structures, the low degree of substitution and the high nitrogen content suggest that primarily humified compounds were formed in situ. Nevertheless, the River Po can act both as supplier of organic matter of which decomposition products lead to the formation of humic compound and as carrier of humified compounds.

Trace elements in organs and tissues of striped dolphins (Stenella coeruleoalba) from the Mediterranean sea (Southern Italy).

The distribution of metals (Cd, Cu, Zn, Fe, Cr, Pb and Sn) were investigated in various tissues and organs obtained from striped dolphins (Stenella coeruleoalba) stranded along the Apulian coasts (Southern Italy) during April-July 1991. Metals were determined by atomic absorption spectrophotometry. Metal concentrations were generally high in the liver, and low in brain and melon. Some metals showed organ-specific accumulations: copper, tin and zinc exhibited high concentrations in liver, the highest cadmium concentration was observed in kidney. Pathological, microbiological and parasitological surveys were performed on the animals. It was not possible to relate dolphin death to a specific cause, or to contaminants; however, the accumulation of metals may contribute to certain pathological alterations.

Accumulation and tissue distribution of mercury and selenium in striped dolphins (Stenella coeruleoalba) from the Mediterranean Sea (southern Italy).

Tissues and organs from Stenella coeruleoalba stranded along the Apulian coasts (southern Italy) during the period April-July 1991 were analyzed for their mercury and selenium content. Analysis showed considerable variations in the mercury concentration in the examined organs and tissues. The highest concentrations of mercury were found in the liver (from 2.27 to 374.50 microg g(-1) wet wt.). After the liver, lung, kidney, muscle and brain were the most contaminated, while the lowest mercury contamination was found in the melon. As mercury, the liver also showed the highest selenium levels. Liver samples were also analyzed for their methyl mercury contents. The role of selenium in detoxification process of methyl mercury has been discussed. Mercury concentrations related to geographic variations and pollution of the marine environment have been examined. The possible implications between mercury accumulation and dolphin death have also been discussed.

Metal and non-metal micro-pollutants in cultivated soils of Lecce and Brindisi districts (Apulia, southern Italy).

To estimate the presence of metal and non-metal micro-pollutants in the soils of the Lecce and Brindisi districts, an analytical study has been carried out on samples of surface soils taken from agricultural areas. The research has concerned the determination of the following micro-pollutants: Cu, Ni, Cr, Zn, Pb, Be, Cd, As, Hg, Sb e Tl. Statistical techniques, such as Principal Component Analysis and Clustering Analysis, have been utilised to examine the correlations among the different parameters and to define contamination areas. The results show that the amount of micro-pollutants in the superficial stratum of the examined soils is in the range permitted by the regulations in force, with the exception of arsenic and thallium. Arsenic concentrations are near to the maximum admissible value, while thallium concentrations are in 56% of the samples higher than the admissible value both in the soil and underground. The most significant parameter from a toxicological point of view is thallium, which has its maximum concentration in the soils located near the industrial area of Brindisi.

Speciation of butyltin compounds in marine sediments with headspace solid phase microextraction and gas chromatography mass spectrometry.

A method for the determination of organotin compounds (monobutyl = MBT, dibutyl = DBT, and tributyltin = TBT) in marine sediments by headspace Solid Phase Microextraction (SPME) has been developed. The analytical procedure involved 1) extraction of TBT, DBT and MBT from sediments with HCl and methanol mixture, 2) in situ derivatization with sodium tetraethylborate and 3) headspace SPME extraction using a fiber coated with poly(dimethylsiloxane). The derivatized organotin compounds were desorbed into the splitless injector and simultaneously analyzed by gas chromatography - mass spectrometry. The analytical method was optimized with respect to derivatization reaction and extraction conditions. The detection limits obtained for MBT, DBT and TBT ranged from 730 to 969 pg/g as Sn dry weight. Linear calibration curves were obtained for all analytes in the range of 30-1000 ng/L as Sn. Analysis of a standard reference sediment (CRM 462) demonstrates the suitability of this method for the determination of butyltin compounds in marine sediments. The application to the determination of TBT, DBT and MBT in a coastal marine sediment is shown.

Sea water contamination in underground waters of salento (Southern Italy).

In the present work, a study of a physico-chemical characterisation of underground waters, utilised for agriculture and human use in the Lecce district (Southern Italy) has been reported. The aim of the work has been to define the quality of underground waters in the different areas and to value salt contamination due to seawater intrusion. Statistical techniques, such as Principal Component Analysis (PCA) and Cluster Analysis (CA), have been utilised to examine the correlations among the different parameters and to define contamination areas. The results have shown a high salt contamination in artesian wells of the Ionian Sea coast.

Tissue distribution of metals in striped dolphins (Stenella coeruleoalba) from the Apulian coasts, southern Italy.

Tissue distributions of metals (mercury, lead, cadmium, zinc, copper, iron, manganese) were determined in six specimens of striped dolphins (Stenella coeruleoalba, Meyen) stranded on the Apulian coasts (Southern Italy) between February and June 1987. Methyl mercury and selenium were also determined in the liver samples. The liver accumulated the highest concentrations of metals, except for cadmium and chromium. Metal levels were higher than those found in dolphins living in the Atlantic, but lower than those recorded in the same species from the French Mediterranean coasts. Necroscopic surveys found that all specimens were affected by haemorrhagic gastritis, but the cause was not clear. While it was not possible to related the death of dolphins to a specific cause, or to contaminants, the accumulation of metals is likely to contribute to the health of the organism and represents a risk factor for dolphins.

In vitro antitumour activity and cellular pharmacological properties of the platinum-iminoether complex trans-[PtCl2[E-HN=C(OMe)Me]2].

The platinum complex trans-[PtCl2¿E-HN=C(OMe)Me¿2] was compared to cisplatin for cytotoxicity towards tumour cells, and for cellular pharmacological properties in A2780 and cisplatin-resistant A2780/Cp8 ovarian cancer cells. Trans-[PtCl2¿E-HN=C(OMe)Me¿2] was comparably cytotoxic to cisplatin (mean IC50 after 72 h exposure = 6. 1 microM and 7 microM, respectively) and did not show cross-resistance in A2780/Cp8 cells (resistance factor = 0.9). Cellular accumulation measurements after treatment with equimolar drug concentrations showed that trans-[PtCl2¿E-HN=C(OMe)Me¿2] entered both A2780 and A2780/Cp8 cells much more efficiently than cisplatin, whose accumulation was reduced in A2780/Cp8 cells. Unlike cisplatin, trans-[PtCl2¿E-HN=C(OMe)Me¿2] induced rapidly cell death and cell cycle modifications of treated cells, thus indicating substantially different mechanistic properties.

In vitro and in vivo antitumour activity and cellular pharmacological properties of new platinum-iminoether complexes with different configuration at the iminoether ligands.

In order to widen our knowledge on antitumour trans-[PtCl2(iminoether)2] complexes, we have synthesised two new derivatives, trans-[PtCl2¿E-HN = C(OEt)Me¿2] (1) and trans-[PtCl2¿Z-HN = C(OEt)Me¿2] (2), which differ in the configuration of the iminoether ligands. Isomer 1 showed an in vitro cytotoxicity similar to that of cisplatin in a panel of human tumour cell lines (mean IC50 = 8 and 7.7 microM, respectively), whereas isomer 2 showed a lower activity (IC50 = 14.3 microM). Both 1 and 2 isomers overcame cisplatin resistance of ovarian cancer cell line A2780/Cp8. In agreement with the n-octanol/saline partition ratios, intracellular platinum content (and DNA platination) after a 2-h exposure to equimolar drug concentrations was in the order 1 > 2 >> cisplatin, thus indicating that substitution of imminoethers for ammines determines a major lipophilicity and cellular uptake of the platinum drug. Both 1 and 2 showed a major toxic effect towards an excision repair-defective Drosophila strain, thus indicating cellular DNA as cytotoxic target. Finally, both 1 and 2 were active in vivo against the murine P388 system, but, contrary to the in vitro activity, isomer 2 was slightly more active than 1. On the whole, the results confirm the antitumour activity of trans-[PtCl2(iminoether)2] complexes, and indicate that the configuration of the iminoether ligands may affect the pharmacological properties of this class of complexes.

Platinum(II) complexes containing iminoethers: a trans platinum antitumour agent.

The biological activity of cis and trans complexes of formula [PtCl2(HN = C(OMe)Me)2] has been investigated. The iminoether ligands can have either E or Z configuration about the C = N double bond, therefore EE, EZ and ZZ isomers are obtainable. Substitution of iminoether with EE configuration for amine leads to unexpectedly high antitumor activity for the complex with trans geometry which turns out to be more active than the cis congener in the P388 leukaemia system. The same trans-EE complex shows an activity comparable to that of cisplatin in reducing the primary tumour mass and lung metastases in mice bearing Lewis lung carcinoma, thus representing a trans platinum complex active on both limphoproliferative and solid metastasizing murine tumours. Also the cytotoxicity, the inhibition of DNA synthesis and the mutagenic activity, which are greater for the cis- with respect to the trans-isomer in the amine complexes, are instead greater for the trans- than for the cis- isomer in the case of iminoether compounds. Binding to calf thymus DNA is slower for iminoether complexes than it is for amine complexes, however after 24 h reaction time the level of binding is similar for both types of complexes. Trans-EE, like trans-DDP, does not give the DNA conformational alterations (terbium fluorescence) typical of antitumour-active cis- platinum compounds, but, under strictly analogous experimental conditions, shows a greatly reduced DNA interstrand cross-linking ability (heat denaturation/renaturation assay) with respect to either trans-DDP or cis-EE and cis-DDP. The data in hand point to a new trans platinum antitumour complex with a mechanism of action different from that of cis-DDP and classical analogues.

Direct determination of seleno-amino acids in biological tissues by anion-exchange separation and electrochemical detection.

Several studies have described the determination of selenium in protein extracts from tissues of marine or terrestrial animals, but have not identified the different chemical forms of selenium that are present. Selenium may be present as seleno-amino acids. Selenocysteine, for example, is a normal component of glutathione peroxidase, an antioxidant enzyme which may behave like other antioxidants, such as vitamin E, protecting tissues against methylmercury toxicity. The present study illustrates a method for the characterization of seleno-amino acids, such as selenocysteine and selenomethionine, in proteins extracted from the liver of marine mammals. The mechanism of detoxification of methylmercury, which involves seleno-compounds, is identified. The analytical determination was carried out using high-performance anion-exchange chromatography coupled with integrated pulsed amperometric detection (HPAEC-IPAD). This method allows the direct determination of underivatized amino acids, eliminating the procedure of pre- or postcolumn derivatization. The chromatographic separation was carried out on an anion-exchange column using a quaternary gradient elution. In order to optimize this method, interferences of amino acids and the influence of pH and ionic strength on the separation and electrochemical detection were studied. The IPAD response for the direct detection of amino acids is optimum at pH > 11. The detection limit (S/N = 3) for selenocysteine was found to be 450 micrograms/l. The application of this method for the identification of seleno-amino acids in protein hydrolysates is also shown.