Zooplankton responses to hydrological and trophic variability in a Mediterranean coastal ecosystem (Lesina Lagoon,South Adriatic Sea)

Spatial and temporal variability in zooplankton was studied at eight stations located in the Lesina Lagoon (South Adriatic Sea) Salinity, temperature, dissolved oxygen and chlorophyll a (in the lagoon) at these stations were also assessed. The zooplankton community was characterised by clear seasonal oscillations and mostly represented by copepods and their larvae. The dominant copepod species were Calanipeda aquaedulcis and Acartia tonsa, which exhibited spatial–temporal segregation in the lagoon. C. aquaedulcis copepodites seemed to be better adapted to oligotrophic and oligohaline conditions compared with the A. tonsa population. The invasive species A. tonsa has completely replaced the formerly abundant Acartia margalefi. A positive correlation was found between abundances, total species numbers and trophic state. An increasing abundance trend was shown from the lagoon towards the sea. The highest diversity indices were recorded at the two channel inlets, during high tide due to the absence of a clear dominance of one or more coastal species and the co-occurrence of species of lagoon and marine origin.     

A flux-based assessment of the effects of ozone on foliar injury, photosynthesis, and yield of bean (Phaseolus vulgaris L. cv. Borlotto Nano Lingua di Fuoco) in open-top chambers

Stomatal ozone uptake, determined with the Jarvis' approach, was related to photosynthetic efficiency assessed by chlorophyll fluorescence and reflectance measurements in open-top chamber experiments on Phaseolus vulgaris. The effects of O₃ exposure were also evaluated in terms of visible and microscopical leaf injury and plant productivity. Results showed that microscopical leaf symptoms, assessed as cell death and H₂O₂ accumulation, preceded by 3-4 days the appearance of visible symptoms. An effective dose of ozone stomatal flux for visible leaf damages was found around 1.33 mmol O₃ m⁻². Significant linear dose-response relationships were obtained between accumulated fluxes and optical indices (PRI, NDI, ΔF/F_m^′). The negative effects on photosynthesis reduced plant productivity, affecting the number of pods and seeds, but not seed weight. These results, besides contributing to the development of a flux-based ozone risk assessment for crops in Europe, highlight the potentiality of reflectance measurements for the early detection of ozone stress.     

Evaluation of Direct-Oxidative DNA Damage on Human Lung Epithelial Cells Exposed to Urban Airborne Particulate Matter

Airborne particulate matter (PM) extracts were investigated for their content of organic compounds and for the direct and oxidative DNA damage induced on lung epithelial cells A549. PM₁₀ was seasonally collected at two monitoring sites (Stations 1 and 2), characterized by different traffic loads. The cells were exposed for 30 min to extracts of PM₁₀ diluted at 0.025%, 0.05%, and 0.1% for summer samples, and at 0.05%, 0.1%, and 0.15% for winter samples. Oxidative and direct DNA damage were evaluated by formamidopyrimidine glycosylase (fpg) comet assay analyzing tail moment (TM) values from fpg-enzyme-treated cells (TMenz) and enzyme untreated cells (TM) respectively and by comet percentage analysis. Measurements relating to Station 2 showed higher levels of polycyclic aromatic hydrocarbons (PAHs), and their methyl-(methyl-PAHs) and nitro-(nitro-PAHs) derivatives in both the seasons. Nitro-PAH concentrations were higher in summer than in winter at both the stations. We found a significant increase of comet percentages at the highest dose of extract from both stations in summer and from Station 2 in winter. The TM and TMenz values relative to the summer sampling showed an early oxidative DNA damage induction also followed by direct DNA damage more evident at Station 2, that seems to correlate with the presence of higher nitro-PAH concentrations during the warm season. At both monitoring stations, the results from winter sampling campaign showed a direct DNA damage induction at 0.1% of extract and oxidative-direct DNA damage at the highest dose (0.15%).     

TEQ(S) and body burden for PCDDs, PCDFs, and dioxin-like PCBs in human adipose tissue

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), mono-ortho and non-ortho polychlorinated biphenyls (dioxin-like PCBs) were determined in samples of human fat tissue from nine Italian obese patients. The toxicity equivalent (TEQ) values ranged from 9 to 25pgTEQg(-1) lipid (WHO-TEF values, 2005 [Van den Berg, M., Birnbaum, L.S., Denison, M., De Vito, M., Farland, W., Feeley, M., Fiedler, H., Hakansson, H., Hanberg, A., Haws, L., Rose, M., Safe, S., Schrenk, D., Tohyama, C., Tritscher, A., Tuomisto, J., Tysklind, M., Walker, N., Peterson, R.E., 2006. The 2005 World Health Organization reevaluation of human and mammalian Toxic Equivalency Factors for dioxins and dioxin-like compounds. Toxicol. Sci. 93, 223-241]), the contribution of dioxin-like PCBs was more than 30% of the total TEQ values. The obese body burdens varied from 6 to 11ngTEQkg(-1) body weight (BW), exceeding the estimated steady-state body burden 5ngTEQkg(-1) BW, based on lipid adjusted serum concentrations from several populations in the mid-1990s, calculated in the risk assessment US EPA document.     

A study on PCB, PCDD/PCDF industrial contamination in a mixed urban-agricultural area significantly affecting the food chain and the human exposure. Part I: soil and feed

This study deals with a PCB, PCDD and PCDF contamination in Brescia, a city in the North-West of Italy, affecting an area with about 11000 inhabitants. The area is close to an industrial plant that produced, in total, some 31,000 ton of PCB. A relevant part of the polluted area is agricultural soil, where cattle were fed with polluted forage and farmers were consuming their own products, so that contamination led eventually to human exposure. Total levels of PCDD/Fs varied from 8 to 592 pgTE(WHO)/g for soil samples and when the dioxin-like PCBs (dl-PCBs) are included, the levels varied from 14.6 to 1033.7 pgTE(WHO)/g. In several cases, the legal limit was exceeded by more than one order of magnitude, with the highest contamination in some agricultural areas and in the surrounding zones. For the forage samples, total levels of PCDD/Fs varied from 0.29 to 2.04 pgTE(WHO)/g and, when dl-PCBs are included, this range increased from 2.04 to 4.75 pgTE(WHO)/g. PCB contamination of the forage through vapor condensation seemed to be relevant. The toxic contribution of dl-PCBs is always relevant and must be considered for risk management. The main component of the contamination source is probably a heavy PCB mixture, such as Aroclor 1262. The study dealt generally with the contamination transfer of PCBs, PCDDs and PCDFs from soil up to humans across the food chain. Results on soils and forages are shown, while measurements concerning the contamination of the animals fed with contaminated forage, and the exposure of the farmers (through human serum analyses), as compared to general population, will be reported in a dedicated paper.     

Enhancement of source traceability of atmospheric PM by elemental chemical fractionation

During a 1-year study (“Fine dust” Project) funded by the Lazio regional government (Italy), about 1000 daily PM₁₀ and PM_2.5 samples collected from six sites in the region were subjected to chemical fractionation based on differences in elemental solubility. In this way, it was possible to achieve meaningful characterization of the elemental composition of individual samples. For most of the investigated elements, we found significant differences between the extracted and the mineralized residual fraction. In general, fine particulate was best characterized by the composition of the extracted fraction, while coarse particles from traffic-related sources were best characterized using residues. For several metals (Cd, Pb, Sn, Sb and V) having a critical environmental impact, this result was particularly clear.The application of Principal Component Analysis (PCA) and receptor modelling (PCR) to the data set allowed us to evidence the enhancement of selectivity towards different emission sources that is obtained when chemical fractionated data are considered instead of total element content. Chemical fractionation seems to generate very selective markers for specific emission sources and in particular for re-suspended road dusts, one of the main factors responsible for the increase of elemental concentrations in urban areas.     

Using optical remote sensing techniques to track the development of ozone-induced stress

In this paper, a literature review about optical remote sensing (RS) of O₃ stress is presented. Studies on O₃-induced effects on vegetation reflectance have been conducted since late ‘70s based on the analysis of optical RS data. Literature review reveals that traditional RS techniques were able to detect changes in leaf and canopy reflectance related to O₃-induced stress when visible symptoms already occurred. Only recently, advanced RS techniques using hyperspectral sensors, demonstrated the feasibility of detecting the stress in its early phase by monitoring excess energy dissipation pathways such as chlorophyll fluorescence and non-photochemical quenching (NPQ). Steady-state fluorescence (Fs), measured by exploiting the Fraunhofer line depth principle and NPQ related xanthophyll-cycle, estimated through the photochemical reflectance index (PRI) responded to O₃ fumigation before visible symptoms occurred. This opens up new possibilities for the early detection of vegetation O₃ stress by means of hyperspectral RS.     

A field screening test for the assessment of concentrations and mobility of potentially toxic elements in soils: a case study on urban soils from Rome and Novi Sad

The increasing demand for environmental pollution control results in the development and use of new procedures for the determination of dangerous chemicals. Simple screening methods, which can be used directly in the field for a preliminary assessment of soil contamination, seem to be extremely advantageous. In our laboratory, we developed and optimized a rapid test for a preliminary evaluation of both the concentration and the mobility of some potentially toxic metals in soils. This screening test consists of a single extraction of the soil sample with a buffer solution, followed by the titration of the extracted solution with dithizone to determine the contents of bi-valent heavy metals (such as Pb, Cu, Zn, and Cd). This screening method was then directly applied in the field during the sampling campaign in the framework of an Italian–Serbian collaborative project, finalized in the study of metal availability in soils. The results obtained in the field with the rapid test were compared with those obtained in the laboratory following the conventional procedure commonly used to evaluate metal bioavailability (diethylenetriaminepentaacetic extraction). Moreover, selected samples were analyzed sequentially in the laboratory using the standardized BCR three-step sequential extraction procedure. The screening test gave results conceptually in good agreement with those obtained via the BCR procedure. These preliminary data show that the proposed screening test is a reliable method for the preliminary rapid evaluation of metal total concentrations and of potential metal mobility in soils, supporting sampling activities directly in the field.