Trace elements in sediments in a city with agricultural development

The objective of this study was to determine the concentrations of trace elements in sediment samples taken from impermeable urban areas of a city with predominantly agroindustrial development characteristics. For this, samples were taken every month from paved streets in the city of Toledo, Paraná State (PR), Brazil. Thus, trace element levels were obtained through analysis performed by optical emission spectrometry with inductively coupled plasma. Levels of total organic carbon were also obtained through the dry combustion method. When compared to local background levels, the trace element levels were shown to be enriched in the following percentage proportions: barium (Ba) (45.4%), copper (Cu) (48.6%), chromium (Cr) (37.2%), manganese (Mn) (81.6%), nickel (Ni) (0%), lead (Pb) (40%), zinc (Zn) (283.7%), magnesium (Mg) (34.3%), and sodium (Na) (250.2%), whereas the carbon (C) percentages were around 1%. The most significant enrichment factors occurred for Ba, Cr, Pb, Zn, Mg, and Na. The highest rates occurred in geoaccumulation where the sediments were enriched by zinc. According to the principal guidelines, the concentrations obtained for cadmium (Cd), Cr, Cu, Ni, and Zn can cause adverse environmental impacts.     

Mutagenic properties of PM2.5 air pollution in the Padana Plain (Italy) before and in the course of XX Winter Olympic Games of "Torino 2006"

PM2.5 is one of the most important aspects of environmental health. This air pollutant is breathable and it is implicated in several chronic adverse health effects such as the decrease of respiratory functionality and cancer. Several in vitro bioassays are able to predict the mutagenic/carcinogenic activity of the environmental pollutants and mixtures of them. In this study PM2.5 air pollution was daily monitored in three cities located in the Northern part of Italy and the mutagenic properties of the PM2.5 organic extracts were also assessed. Samplings lasted 14 months and cover the period of the Winter Olympic Games of "Torino 2006". In this work, the levels of PM2.5, its mutagenic properties (detected with Salmonella typhimurium assay), the role of the Olympic Games as environmental factor and some meteorological data are discussed. The mean concentration of PM2.5 measured in Torino was 45.4 (+/-30.6) microg/m(3), in Pavia 37.6 (+/-25.6) microg/m(3), in Verona 43.1 (+/-28.5) microg/m(3). Findings of the monthly pool bioassay were in Torino 107 (+/-104) net revertans/m(3), in Pavia 108 (+/-89) net revertans/m(3), in Verona 128 (+/-109) net revertans/m(3). The Olympic Games period data show that PM2.5 pollution and its load of mutagenic potential are different and partially independent phenomena. The Olympic Games had not a great impact on the PM2.5 pollution. The exclusive PM2.5 gravimetric analysis shows a potential human risk if compared with the latest international guide values but it does not describe exhaustively the human health risk associated to the presence of this particular air pollutant. Moreover, the chemical and biological activity qualification of the PM organic extracts as a whole, can instead improve the knowledge.     

14C content in vegetation in the vicinities of Brazilian nuclear power reactors

(14)C specific activities were measured in grass samples collected around Brazilian nuclear power reactors. The specific activity values varied between 227 and 299 Bq/kg C. Except for two samples which showed (14)C specific activities 22% above background values, half of the samples showed background specific activities, and the other half had a (14)C excess of 1-18%. The highest specific activities were found close to the nuclear power plants and along the main wind directions (NE and NNE). The activity values were found to decrease with increasing distance from the reactors. The unexpectedly high (14)C excess values found in two samples were related to the local topography, which favors (14)C accumulation and limits the dispersion of the plume. The results indicate a clear (14)C anthropogenic signal within 5 km around the nuclear power plants which is most prominent along northeastwards, the prevailing wind direction.     

Analysis of the eastern Pacific yellowfin tuna fishery based on multiple management objectives

Vector optimization techniques were used to generate arbitrary segments of a policy frontier for a dynamic yellowfin tuna (Thunnus albacares) fishery model assuming fixed technology and considering four policy objectives: minimizing dolphin mortality, minimizing incidental catch (all species except dolphins), maximizing sustainable yield, and minimizing biological risk for the yellowfin tuna stock. Results show that along the policy frontier: (1) reducing incidental dolphin mortality increases the incidental catch of other species in a nonlinear way; (2) yield increases (subject to a biomass precautionary level) can only be obtained at the expense of higher levels of dolphin mortality and incidental catch; (3) biological risk increases as the level of tunas caught increases, but this increase depends on the type of fishery (longline fishing and three different modes of purse-seining: log-sets, dolphin-sets or school-sets) that dominates the fishing effort; (4) there is an indirect relationship between the dolphin mortality levels and those of biological risk; (5) there is a direct relationship between the incidental catch levels and biological risk. Catch obtained with dolphin-sets dominates the Pareto-optimal solutions with highest dolphin mortality levels but is associated with lower biological risk, whereas catch obtained with log-sets dominates in Pareto-optimal solutions with higher incidental catch and higher biological risk. In general, trade-offs or shadow prices among objectives are not linear, indicating that marginal costs vary along the policy frontier. Results of the trade-off analysis may provide useful information for decision-makers and other policy actors. Complete information about the preferences of the decision-makers regarding the objectives is necessary to recommend a specific management policy.     

Effects of intensive mariculture on sediment biochemistry.

The exponential growth of off-shore mariculture that has occurred worldwide over the last 10 years has raised concern about the impact of the waste produced by this industry on the ecological integrity of the sea bottom. Investigations into this potential source of impact on the biochemistry of the sea floor have provided contrasting results, and no compelling explanations for these discrepancies have been provided to date. To quantify the impact of fish-farm activities on the biochemistry of sediments, we have investigated the quantity and biochemical composition of sediment organic matter in four different regions in the temperate-warm Mediterranean Sea: Akrotiri Bay (Cyprus), Sounion Bay (Greece), Pachino Bay (Italy), and the Gulf of Alicante (Spain). In these four study regions, the concentrations of phytopigments, proteins, carbohydrates, and lipids in the sediments were measured, comparing locations receiving wastes from fish farms to control locations in two different habitats: seagrass beds and soft nonvegetated substrates. Downward fluxes were also measured in all of the regions, up to 200 m from the fish farms, to assess the potential spatial extent of the impact. In all four regions, with the exception of seagrass sediments in Spain, the biochemistry of the sediments showed significant differences between the control and fish-farm locations. However, the variables explaining the differences observed varied among the regions and between habitats, suggesting idiosyncratic effects of fish-farm waste on the biochemistry of sediments. These are possibly related to differences in the local physicochemical variables that could explain a significant proportion of the differences seen between the control and fish-farm locations. Biodeposition derived from the fish farms decreased with increasing distance from the fish-farm cages, but with different patterns in the four regions. Our results indicate that quantitative and qualitative changes in the organic loads of the sediments that arise from intensive aquaculture are dependent upon the ecological context and are not predictable only on the basis of fish-farm attributes and hydrodynamic regimes. Therefore, the siting of fish farms should only be allowed after a case-by-case assessment of the ecological context of the region, especially in terms of the organic matter load and its biochemical composition.     

Vocalizations and courtship intensity correlate with mounting success in marginated tortoises<Emphasis Type="Italic"> Testudo marginata</Emphasis>

The courtship and mounting behaviour of tortoises is elaborate, and based on a multiple signalling system involving visual, olfactory and acoustic signals. Vocalizations related to mounting seem to be particularly significant because tortoises vocalize mainly at this time. Vocalizations and courtship behaviour may be costly for males, and if these costs increase differentially for different males, then the potential exists for vocalizations and displays to reveal male individual quality. In this correlative study, we analysed relationships between male mounting success and morphological and behavioural traits, particularly acoustic signals, exhibited by male marginated tortoises (Testudo marginata) during courtship, in a group of 94 individuals breeding in semi-natural enclosures. For each male, we estimated general body condition, courtship intensity and mounting success; calls of mounting males were recorded and four sonagraphic features were measured. Calls differed significantly among males, and two features varied according to body condition. Male mounting success significantly increased according to the male/female size-ratio, suggesting the existence of a size-based assortative mating. Mounting success was also highly correlated with courtship intensity, measured as number of bites and rams given to females before mounting, and with number of calls emitted during mounting. Finally, mounting success was negatively related to call duration. To our knowledge, this is the first study in which features of tortoise vocalizations are shown to convey reliable information about male quality in socio-sexual contexts.Communicated by T. Czeschlik     

Sterols in sediment samples from Venice Lagoon, Italy

Sterols of different origin were analysed in sediment samples collected in the Venice Lagoon. The purpose of the study was to investigate the degree of sewage contamination within the Lagoon using fecal sterols (coprostanol, epicoprostanol and coprostanone) and to analyse the pattern of the sterols to plot the origin of the organic matter.

Sedimentary coprostanol at Canal Grande within the city of Venice was more than one order of magnitude higher than other stations in the Lagoon and two orders higher than in a sediment sample collected in the open sea. The cholesterol/coprostanol ratio, like the percentage of coprostanol in total sterols at this sample site was very similar to values in sewage sludge. The different pattern of sterols at station 2 which had the largest amount of total sterol indicates a difference in the origin of the organic material. Nevertheless the sterols used as tracer of terrestrial vascular plants did not show any particular trend at this station, receiving fresh water inputs. (3-Sitosterol and cholestanol reached the highest levels at the station within the Chioggia basin.     

Pharmaceuticals in STP effluents and their solar photodegradation in aquatic environment

The presence of pharmaceutical compounds in surface waters is an emerging environmental issue. Sewage treatment plants (STPs) are recognized as being the main point discharge sources of these substances to the environment. A monitoring campaign of STP effluents was carried out in four European countries (Italy, France, Greece and Sweden). More than 20 individual pharmaceuticals belonging to different therapeutic classes were found. For six selected pharmaceuticals (carbamazepine, diclofenac, clofibric acid, ofloxacin, sulfamethoxazole and propranolol) present in the STP effluents, the persistence towards abiotic photodegradation was evaluated submitting them to solar experiments at 40° N latitude during spring and summer. Based on experimentally measured quantum yields for the direct photolysis in bi-distilled water, half-life times (t_1/2) at varying seasons and latitude were predicted for each substance. In salt- and organic-free (bi-distilled) water carbamazepine and clofibric acid are characterized by calculated half-life times of the order of 100 days at the highest latitudes (50° N) in winter, whereas under the same conditions sulphamethoxazole, diclofenac, ofloxacin and propranolol undergo fast degradation with t_1/2 respectively of 2.4, 5.0, 10.6 and 16.8 days. For almost all studied compounds, except propranolol the presence of nitrate ions in aqueous solutions results in a reduction of t_1/2. When present, humic acids act as inner filters towards carbamazepine and diclofenac, and as photosensitizers towards sulphamethoxazole, clofibric acid, oflaxocin and propranolol.     

Spray-dry desulfurization of flue gas from heavy oil combustion

An experimental investigation on sulfur dioxide removal in a pilot-scale spray dryer from the flue gas generated by combustion of low-sulfur (S) heavy oil is reported. A limewater slurry was sprayed through an ultrasonic two-fluid atomizer in the spray-dry chamber, and the spent sorbent was collected downstream in a pulse-jet baghouse together with fly ash. Flue gas was sampled at different points to measure the desulfurization efficiency after both the spray-dry chamber and the baghouse. Parametric tests were performed to study the effect of the following variables: gas inlet temperature, difference between gas outlet temperature and adiabatic saturation temperature, lime-to-S ratio, and average size of lime particles in the slurry. Results indicated that spray drying is an effective technology for the desulfurization of low-S fuel oil flue gas, provided operating conditions are chosen carefully. In particular, the lowest gas inlet and outlet temperatures compatible with baghouse operation should be selected, as should a sufficiently high lime-to-S ratio. The attainment of a small lime particle size in the slurry is critical for obtaining a high desulfurization efficiency. A previously presented spray-dry flue gas desulfurization model was used to simulate the pilot-scale desulfurization tests, to check the ability of the model to predict the S capture data and its usefulness as a design tool, minimizing the need for pilot-scale experimentation. Comparison between model and experimental results was fairly good for the whole range of calcium/S ratios considered.     

Seabird eggs as bioindicators of chemical contamination in Chile

Seabird eggs were used as bioindicators of chemical contamination in Chile. Brown-hooded Gull (Larus maculipennis), Kelp Gull (Larus dominicanus), Trudeau's Tern (Sterna trudeaui), Neotropic Cormorant (Phalacrocorax brasilianus), and Pink-footed Shearwater (Puffinus creatopus) eggs were sampled at different breeding sites during the 1990s. Mercury and organochlorines (PCBs, DDT, HCB, HCH, and PCP) were quantified to reveal the interspecific differences, spatial and temporal trends in contamination levels. Trudeau's Tern displayed the highest levels of mercury (486 ng g(-1) wet weight). The highest sumDDT concentrations were measured in Brown-hooded Gulls (726 ng g(-1)). PCB levels were similar among the species (102-236 ng g(-1)), but the composition of the PCB mixture was different in Pink-footed Shearwaters. With the exception of the Brown-hooded Gull, all species studied presented similar and low levels of organochlorines (sumOHa). Residues of PCB and related compounds were not detected in any of the seabird eggs analyzed in Chile. Geographical variation was low, although levels of industrial chemicals were slightly higher in eggs from Concepción Bay, and agricultural chemicals in eggs from Valdivia. Also interannual variation was low, but some evidence was found of decreasing levels in gull eggs throughout the time of the study. The causes of the low levels and small variability in space and time of environmental chemicals in Chilean seabirds are discussed. We propose the use of seabirds in future monitoring of the development of chemical contamination in Chile.