Design,Modelling and Assessment of Emission Scenarios Resulting from a Network of Wood Biomass Boilers

The use of wood biomass as a fuel for domestic and industrial heating systems allows for a reduction of CO₂ emissions at a global scale, but it may also result in worse local air quality conditions, due to their emissions of particulate matter. The aim of this study is to assess the actual trend of atmospheric pollution in a study area, assuming that all heating systems are replaced by small size biomass boilers linked to the buildings through district heating network. Ground level concentrations of particulate matter, emitted by different heating systems, are therefore evaluated through numerical simulations performed by means of an atmospheric dispersion model (Sirane). As a first step, we have compared the environmental impact of a woodchip boilers network with that given by the use of traditional heating systems, i.e. wood stoves and natural gas boilers. As a second step, we have analysed the impact of such a network taking into account different emission scenarios, related to different boilers operating conditions. Results show that the environmental performances of a woodchip boilers network can be optimized by combining it with other renewable sources of energy devoted to the supply of hot water. The adopted analysis methodology can be applied to other real or hypothetic punctual sources on the territory.     

Validity and reliability of a job factors questionnaire related to the work tasks of physical therapists

Physical therapists engage in work tasks that expose them to occupational risk factors related to musculoskeletal disorders. Due to the gap in the literature on instruments focused on those workers, this study adapted a job factors questionnaire to physical therapists, and assessed its psychometric properties. The questionnaire was adapted and its content validity was established. The psychometric properties were evaluated among 142 physical therapists. Reliability was verified using the temporal-stability design and internal consistency. Construct validity was assessed with the known-groups technique. Test-retest results demonstrated intraclass correlation coefficients between .82 and .90 (p < .001). Cronbach's α of .91 verified the reliability of the questionnaire. The known-groups technique demonstrated a statistically significant difference on the scores of the items when physical therapists were compared to office workers. The results indicated that the adapted questionnaire had acceptable psychometric properties for assessing problematic job factors among physical therapists working in hospitals.     

Estimation of Similarity in the Qualitative Composition of Humic Substance in Marine Sediments By Means of an Uv-Spectroscopic Library

In this paper a method for the study of the qualitative similarity of extractable humic substance (EHS) in marine sediments based on the realisation of UV spectral library of EHS is described. the spectral library was built including the digitised spectra of humic substance extracted from several marine sediments (46 samples) and two samples of standard materials (lignin sulphonate and humic substance) in a Statistica data file. the data matrix was elaborated by means of different multivariate statistic techniques such as Cluster Analysis (CA), Principal Components Analysis (PCA) and the univariate technique Spectral Correlation Analysis (SCA). This approach allows us to show the contribution of different organic compounds (aromatic, lipid and acid) to the composition of EHS and moreover it evidences also the structural characteristics of EHS in terms of similarities in the qualitative composition of samples such as presence of terrestrial and/or vegetal contributions. the UV library is an objective tool to study the qualitative composition of EHS and it represents a complementary approach to the most common methods based on the application of spectroscopic (IR, ¹³CNMR), potentiometric and chromatographic techniques.     

Carbon partitioning among the first trophic levels in the North Western Adriatic Basin

In the frame of PRISMA II Project samples for plankton analyses were carried out during four cruises (June, 1996; February and June, 1997; February, 1998) in order to assess the relative importance in term of biomasses of the three main size fractions (pico- <2 r µm, nano- 2-20 r µm and micro-plankton >20 r µm). Spatial and temporal distribution of the three plankton fractions were described as abundance and contribution to the total carbon content in an area between Po River mouth and Rimini. The relative contribution of picoplankton resulted higher in the offshore zone, while that of nanoplankton in the inshore waters. In February 1998 microphytoplankton, mainly constituted by diatoms, was very abundant in the inshore waters. Micro-zooplankton was always very scarce. Cluster analyses performed on these data grouped the stations on the basis of their community structure, and agreed with the hydrological features. Small size classes contributed more significantly to the total plankton carbon content in most of the situations. Microplankton fraction contribution was relevant only during spring diatom bloom of February 1998 and with a less extent in the confined coastal summer blooms.     

Nutrient balance in the ecosystem of the North Western Adriatic Sea

The effects of biological processes on dissolved inorganic nutrients, dissolved organic nitrogen (DON) and phosphorus (DOP) are considered in the north western Adriatic Sea. The budgets of these nutrients, which represent the sum of production and consumption processes in comparison to advection, are discussed with regard to dissolved inorganic nitrogen ( 15 N labelled) uptake, which basically indicates the biological demand of this fraction of nitrogen by phytoplankton community. The presented data show that, although important, the continental input of dissolved inorganic nitrogen (DIN), mainly nitrate, is utilised and recycled within the coastal marine environment (budget of m 15 r µmol-N·dm m 3 ). In fact, during four cruises (June, 1996; February, 1997; June, 1997; February, 1998), phytoplankton production was mainly driven by regenerated nutrients ( f h 0.4). Regarding dissolved inorganic phosphorus (DIP), the negative budgets observed in most cases (down to m 0.4 r µmol-P·dm m 3 ) confirm, above all, its scarce availability in this basin. Recycling processes rather than continental inputs regulate the availability of this nutrient. In addition, the comparison between DIN and DIP budgets indicates that, in this ecosystem, dissolved inorganic phosphorus is recycled faster than nitrogen through the living particulate and dissolved organic pools. As a consequence of biological activities, a strong production of dissolved organic nitrogen (DON) can occur in summer (up to +22 r µmol-N·dm m 3 ) while DOP shows a more independent behaviour both with respect to its accumulation in the environment and to the observed nitrogen variations.     

Toxic and genotoxic impact of fibrates and their photoproducts on non-target organisms

Lipid regulators have been detected in effluents from sewage treatment plants and surface waters from humans via excretion. This study was designed to assess the ecotoxicity of fibrates, lipid regulating agents. The following compounds were investigated: Bezafibrate, Fenofibrate and Gemfibrozil and their derivatives obtained by solar simulator irradiation. Bioassays were performed on bacteria, algae, rotifers and microcrustaceans to assess acute and chronic toxicity, while SOS Chromotest and Ames test were utilized to detect the genotoxic potential of the investigated compounds. The photoproducts were identified by their physical features and for the first risk evaluation, the environmental impact of parental compounds was calculated by Measured Environmental Concentrations (MEC) using the available data from the literature regarding drug occurrence in the aquatic environment and the Predicted No Effect Concentrations (PNEC) based on our toxicity data. The results showed that acute toxicity was in the order of dozens of mg/L for all the trophic levels utilized in bioassays (bacteria, rotifers, crustaceans). Chronic exposure to these compounds caused inhibition of growth population on rotifers and crustaceans while the algae seemed to be slightly affected by this class of pharmaceuticals. Genotoxic and mutagenic effects were especially found for the Gemfibrozil photoproduct suggesting that also byproducts have to be considered in the environmental risk of drugs.     

Toxicity of tire debris leachates

Data on the indicators of environmental impact of tire debris, originated from the tire abrasion on roads, are extremely scarce, while it is well known that tires may produce deleterious effects. Tire debris contains significant quantities of zinc (Zn) which may be released by tire rubber. We have used tire particles (TD) produced in laboratory from new rubber. Two sets of experiments were set up to obtain eluates. One set used 50 and 100 g/L TD to produce eluates at pH 3-7. The Zn quantity was measured with a Inductively Coupled Plasma-Atomic Emission Spectrometry. The eluates at 1%,10%,50%,100% concentrations in culture media were tested on Raphidocelis subcapitata, Daphnia magna and Xenopus laevis embryos (FETAX test). The other set of experiments was performed putting 250 mg/L TD in a column with glass beads to control particle dispersion during the elution process. We demonstrate that factors such as pH, size and particles aggregation deeply influence the elution process, that the amount of Zn leached from particles is related to their aggregation rather than their quantity. These results, even though do not reflect the real environmental toxicity of the leachates, can be successfully used for comparative purposes allowing an initial assessment of the potential effect of tire derived particles.     

Origin and transport of U and Ra in riverine,estuarine and marine sediments of the Krka River,Croatia

Spatial distribution of ²³⁸U and ²²⁶Ra activities in sediment columns along the Krka River and estuary, were studied using gamma spectrometry. Markedly different ²³⁸U and ²²⁶Ra activities between riverine, estuarine and marine sediments were observed. Distribution of these radionuclides, as well as their anthropogenic and natural origin, was evaluated by activity measurements, taking into account sedimentation rates estimated by ¹³⁷Cs distribution in sediment columns.     

Estrogenic activity of pharmaceuticals in the aquatic environment

In the last years pharmaceuticals have aroused great interest as environmental pollutants for their toxic effects towards non target organisms. This study wants to draw attention to a further adverse effect of drugs, the endocrine interference. The most representative drugs of the widespread classes in environment were investigated. The YES-test and the E-screen assay were performed to detect the capability of these substances to bind the human estrogenic receptor α (hERα) in comparison with 17β-estradiol. Out of 14 tested pharmaceuticals, 9 were positive to YES-assay and 11 were positive to E-screen assay; in particular, Furosemide and the fibrates (Bezafibrate, Fenofibrate and Gemfibrozil) gave the maximal estrogenic response. Tamoxifen showed its dual activity as agonist and antagonist of hERα.