Cytotoxic and genotoxic effects of metal(oid)s bioactivated in rocket leaves (Eruca vesicaria subsp. sativa Miller)

Rocket is an important source of essential elements. However, it may also accumulate toxic elements such as metal(oids). The objectives of the present work were (i) to study the uptake of arsenic, lead, cadmium and zinc in rocket grown in contaminated soils, (ii) to establish the genotoxic and cytotoxic activities of this vegetable material, and (iii) to study the modulator role of the glucosinolate and metal contents in the genotoxic/cytotoxic activities. Lead, cadmium and zinc leaf concentrations in our study were over the concentrations allowed by the statutory limit set for metal(oid) contents in vegetables. The accessions were non genotoxic at the different concentrations studied, although one of the accessions showed the highest mutation rates doubling those of negative control. The cytotoxicity assays with HL60 human leukaemia cells showed that the tumouricide activities of rocket leaves decreased with the increasing of metal(oid) concentrations and also with the decreasing of glucosinolate concentrations in their tissues. An interaction between metal(oid)s and glucosinolate degradation products contained in rocket leaves is suggested as the main modulator agents of the biological activity of the plants grown in metal-contaminated soils.     

Relative influence of the dissolved humic material on the solid-phase extraction efficiency of pesticides from environmental water

The effect of organic matter on the solid-phase extraction (SPE) efficiency for pesticides belonging to different chemical groups (urea-derivatives, carbamates and triazines) and having different polarities, was simultaneously studied for the first time in pure and simulated water samples. SPE was carried out in precolumns packed with C18 silica or styrene-divinylbenzene copolymer PLRP-S phases on-line coupled to high performance liquid chromatography (HPLC) analysis. Retention factors in water (k'_W) were estimated for 25 compounds and used for the calculation of the theoretical breakthrough volume (Vb_T) in pure water. Experimental breakthrough volumes (Vb_E) were first determined using purified and deionized water as the matrix for selected compounds having Vb_T < 500 mL; then, the same water with an added humic acid sodium salt (HA) at 0.4–5.6 mg/L of dissolved organic carbon (DOC) content, was used as the matrix for compounds having VbE < 500 mL in pure water. Several polar pesticides showed negative linear or logarithmic Vb_E curves depending on HA content; their recoveries were also determined in environmental samples having low dissolved organic carbon values, between 0.5–6.4 mg/L. A similar behavior was observed for these compounds in simulated and natural water samples, where DOC concentration and the percolated volume (Vp) mainly determine the solute recoveries values. However, the variation of recoveries as a function of DOC content could be negative or null depending on the two examined conditions (Vp lower or larger than Vb_E in pure water). Results demonstrated that breakthrough volume must always be considered to correctly interpret the participation of dissolved humic material on the SPE efficiency of organic micropollutants in water.     

Polycyclic aromatic hydrocarbon contamination in an urban area assessed by Quercus ilex leaves and soil

We investigated the PAH contamination of Naples urban area, densely populated and with high traffic flow, by analyses of environmental matrices: soil and Quercus ilex leaves. Being some PAHs demonstrated to have hazardous effects on human health, the accumulation of carcinogenic and toxic PAHs (expressed as B(a)Peq) was evaluated in the leaves and soil. The main sources of the PAHs were discriminated by the diagnostic ratios in the two matrices. The urban area appeared heavily contaminated by PAHs, showing in soil and leaves total PAH concentrations also fivefold higher than those from the remote area. The soil mainly accumulated heavy PAHs, whereas leaves the lightest ones. Median values of carcinogenic PAH concentrations were higher in soil (440 ng g^?1 d.w.) and leaves (340 ng g^?1 d.w.) from the urban than the remote area (60 and 70 ng g^?1 d.w., respectively, for soil and leaves). Also, median B(a)Peq concentrations were higher both in soil and leaves from the urban (137 and 63 ng g^?1 d.w., respectively) than those from the remote area (19 and 49 ng g^?1 d.w., respectively). Different from the soils, the diagnostic ratios found for the leaves discerned PAH sources in the remote and urban areas, highlighting a great contribution of vehicular traffic emission as main PAH source in the urban area.     

Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in milk from Italian women living in Rome and Venice

The levels of selected polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were measured in human milk samples from the areas of Venice and Rome, primarily in order to characterize the current levels of infant exposure to PCBs and PBDEs due to breast feeding in Italy. Sixteen non-dioxin-like PCBs, including the traditional indicator congeners, and 11 PBDEs, comprising the relevant PBDE-47, PBDE-99, and PBDE-153, were determined. Congeners were selected for analysis according to their relative abundance in human tissues, toxicological relevance, and diffusion in the environment. Dietary habits of the milk donors were recorded by questionnaires; mothers of the Venice area were classified into three groups according to their consumption of local fish, molluscs, and other fishery products. Sigma(16)(PCBs) and Sigma(11)(PBDEs) (ng g(-1) fat) for the areas of Venice and Rome were respectively, 250-390 and 240, and 1.6-2.8 and 4.1. An increase of fish and fishery product consumption could not be associated with an increase of PCB and PBDE levels in milk.     

Measuring, modelling and testing ozone exposure, flux and effects on vegetation in southern European conditions--what does not work? A review from Italy

Ozone (O3) exposure at Italian background sites exceeds UN/ECE concentration-based critical levels (CLe(c)), if expressed in terms of AOT40. Yet the occurrence of adverse effects of O3 on forests and crops is controversial. Possible reasons include (i) ability of response indicators to provide an unbiased estimate of O3 effects, (ii) setting of current CLe(c) in terms of cut-off value and accumulation level, (iii) response functions adopted to infer a critical level, (iv) environmental limitation to O3 uptake and (v) inherent characteristics of Mediterranean vegetation. In particular, the two latter points suggest that critical levels based on accumulated stomatal flux (CLe(f)) can be a better predictor of O3 risk than CLe(c). While this concept is largely acknowledged, a number of factors may limit its applicability for routine monitoring. This paper reviews levels, uptake and vegetation response to O3 in Italy over recent years to discuss value, uncertainty and feasibility of different approaches to risk assessment.     

Impact of elevated CO(2) and nitrogen fertilization on foliar elemental composition in a short rotation poplar plantation

The experiment was carried out on a short rotation coppice culture of poplars (POP-EUROFACE, Central Italy), growing in a free air carbon dioxide enriched atmosphere (FACE). The specific objective of this work was to study whether elevated CO(2) and fertilization (two CO(2) treatments, elevated CO(2) and control, two N fertilization treatments, fertilized and unfertilized), as well as the interaction between treatments caused an unbalanced nutritional status of leaves in three poplar species (P. x euramericana, P. nigra and P. alba). Finally, we discuss the ecological implications of a possible change in foliar nutrients concentration. CO(2) enrichment reduced foliar nitrogen and increased the concentration of magnesium; whereas nitrogen fertilization had opposite effects on leaf nitrogen and magnesium concentrations. Moreover, the interaction between elevated CO(2) and N fertilization amplified some element unbalances such as the K/N-ratio.     

Tree species effect on the redistribution of soil metals

Phytostabilization of metals using trees is often promoted although the influence of different tree species on the mobilization of metals is not yet clear. Soil and biomass were sampled 33 years after planting four tree species (Quercus robur, Fraxinus excelsior, Acer pseudoplatanus, Populus 'Robusta') in a plot experiment on dredged sediment. Poplar took up high amounts of Cd and Zn and this was associated with increased Cd and Zn concentrations in the upper soil layer. The other species contained normal concentrations of Cd, Cu, Cr, Pb and Zn in their tissues. Oak acidified the soil more than the other species and caused a decrease in the concentration of metals in the upper soil layer. The pH under poplar was lower than expected and associated with high carbon concentrations in the top soil. This might be assigned to retardation of the litter decomposition due to elevated Cd and Zn concentrations in the litter.     

Water balances in intensively monitored forest ecosystems in Europe

A soil hydrological model based on Darcy's law was used to calculate hydrological fluxes for 245 intensively monitored forest plots in Europe. Local measured input data for the model were rather limited and input was partly based on generic data. To obtain the best results, the model was calibrated on measured throughfall at the plots. Median transpiration fluxes are 350 mm; median leaching fluxes are 150 mm yr(-1) with the highest values in areas with high rainfall. Uncertainty analyses indicate that the use of local meteorological data instead of generic data leads to lower leaching fluxes at 70% of the plots due to an overestimation of the wind speed on basis of main meteorological stations. The underestimation of the leaching fluxes is confirmed by the median Cl fluxes which were slightly positive for the considered plots.     

Spatial distribution and internal metal concentrations of terrestrial arthropods in a moderately contaminated lowland floodplain along the Rhine River

Soil metal concentrations, inundation characteristics and abundances of 14 arthropod taxa were investigated in a moderately contaminated lowland floodplain along the Rhine River and compared to the hinterland. Internal metal concentrations were determined for the orders of Coleoptera (beetles) and Araneida (spiders) and were related to soil concentrations. The floodplain was characterized by larger arthropod abundance than the hinterland, in spite of recurrent inundations and higher soil metal concentrations. Most arthropod taxa showed increasing abundance with decreasing distance to the river channel and increasing average inundation duration. For Cd, Cu, Pb and Zn, significant relations were found between arthropod concentrations and concentrations in soil. Significant relations were few but positive, indicating that increasing soil concentrations result in increasing body burdens in arthropods. For arthropod-eating vertebrates, these results might imply that larger prey availability in the floodplain coincides with higher metal concentrations in prey, possibly leading to increased exposure to metal contamination.