[Show abstract][Hide abstract] ABSTRACT: A simplified fingerprint, elaborated upon heterotrophic bacterial charge and conventional faecal coliforms (FCs) was used to measure the relative quality of the waters in the western basin of the Orbetello lagoon (Tuscany, Italy). Different bacteriological parameters were combined, after standardisation, obtaining "iso-quality" lines. The-final image of the lagoon exhibits different pollution levels, with a relative minimum in the central area.
[Show abstract][Hide abstract] ABSTRACT: Tracers of environmental contamination generated by the emissions of a small municipal solid waste incinerator were measured in different environmental compartments. Concentrations of OCDD, Hg, As, Cd and Pb in soil and plant foliage mapped in the impacted area revealed a clear fingerprint. The levels of measured contaminants, however, were far from having a toxicological significance. Lichens, used as biological indicators of air quality, revealed a measurable degree of pollution generated by acid emissions only very partially due to the studied source.
No preview · Article · Nov 2000 · Toxicological and Environmental Chemistry
[Show abstract][Hide abstract] ABSTRACT: At Mt. Amiata (Italy) geothermal energy is used, since 1969, to generate electricity in five plants with a nominal capacity of 88 MW. Anomalous levels of mercury characterise geothermal fluids of Mt. Amiata, an area renowned for its vast cinnabar deposits and for the mercury production carried out in the past. Mercury emission rates range from 300 to 400 g/h, or 3-4 g/h per MW electrical installed capacity. These emissions are coupled with a release of 7-8 kg/(h MW) of hydrogen sulphide (H2S). Mercury is discharged as Hg0 gaseous species and reaches the atmosphere with the non-condensable gas fraction. In this fraction, CO, is the major component (94-98%), H2S is around 1% and mercury concentration is as high as 1-10 mg/Nm3. Leaves of a spontaneous grass (Avena sterilis), at the end of the vegetative cycle, were used as mercury bioconcentrators to map deposition near geothermal power plants and to calculate the corresponding average levels of Hg0 in the air. Direct measurements of mercury and hydrogen sulphide vapours in the air reached by power plant emissions showed a ratio of about 1-2000. This ratio was applied to calculate average levels of hydrogen sulphide starting from mercury deposition mapping: typical concentrations of mercury and hydrogen sulphide were of the order of 10-20 ng/m3 and 20-40 microg/m3, respectively.
[Show abstract][Hide abstract] ABSTRACT: A simplified fingerprint, obtained by counting the colonies of luminescent and nonluminescent bacteria developing on filters plated on a solid culture medium, was applied to obtain an indication of coastal water quality. Results from a reference area and three polluted sites (essentially by urban sewage) and their variations during the year are reported. A tentative characterization of the “clean” and polluted sites is made.
No preview · Article · Feb 1997 · Environmental Toxicology and Chemistry
[Show abstract][Hide abstract] ABSTRACT: An evaluation of the potential to reach the ground water compartment of the main applied pesticides in maize fields of the Chamusca agricultural area have indicated atrazine as the most probable contaminant. The use of nitrogen fertilizers in the aforementioned irrigated area also suggested a possible presence of nitrates in ground water. Results of atrazine and nitrate levels in drinking ground water of four locations in the studied area are reported. Residues were detected in three locations and in one of them levels were found above the maximum acceptable concentrations defined by the European Community. The simultaneous presence of atrazine and nitrates in the most affected site suggests a potential health risk.
No preview · Article · Nov 1995 · Toxicological and Environmental Chemistry
[Show abstract][Hide abstract] ABSTRACT: Organochlorine residues were measured in the diet, blood, faeces and exhaled air of captive bottlenose dolphins (Tursiops truncatus) to evaluate the absorption efficiency from food and the eliminatory potential via faeces and exhaled air. Differences between air-breathing and water-breathing animals feeding on similar prey are briefly discussed. It is concluded that high concentrations of recalcitrant organochlorines currently found in marine mammals feeding on fish are essentially due to the lack of branchial elimination and not to their predator status.
[Show abstract][Hide abstract] ABSTRACT: Pesticide disappearance from soils was observed in laboratory studies in which leaching and runoff were impeded, and volatilisation and degradation evaluated. Advection by volatilisation was negligible for the less volatile chemicals, and significant for the more volatile (Trifluralin and Heptachlor). Basic statistics applied to degradation DT50 data of 14 active ingredients in four different soils showed that the properties of pesticides play a major role in determining their degradability.
[Show abstract][Hide abstract] ABSTRACT: The acute toxicities of five s-triazines (atrazine, prometryn, simetryn, ametryn, terbutryn) were measured using two algae (one freshwater species, Selenastrum capricornutum, and one marine species, Dunaliella tertiolecta), Microtoxr̀ bacteria, and the brine shrimp, Artemia salma. The algae were one to three orders of magnitude more susceptible to tested compounds than were bacteria or brine shrimp. The transformation of effective concentrations of the chemicals, obtained from toxicity measurements, into percent of the saturation level in water is proposed as a first evaluation of potential hazard to aquatic systems. Simetryn was found to be the most hazardous s-triazine for all species tested.
No preview · Article · Jun 1995 · Environmental Toxicology and Chemistry
[Show abstract][Hide abstract] ABSTRACT: Atrazine and nitrate levels found in ground water samples from an unconfined aquifer in the agricultural area of Chamusca (Portugal) are reported. High levels of both, atrazine (0.3–0.4 μg/L) and nitrates (≈100 mg/L) were found in Azinhaga area, located downstream to the main corn production area.
No preview · Article · Jun 1995 · Toxicological and Environmental Chemistry
[Show abstract][Hide abstract] ABSTRACT: The acute toxicities of five s-triazines (atrazine, prometryn, simetryn, ametryn, terbutryn) were measured using two algae (one freshwater species, Selenastrum capricornutum, and one marine species, Dunaliella tertiolecta), Microlox® bacteria, and the brine shrimp, Artemia salina. The algae were one to three orders of magnitude more susceptible to tested compounds than were bacteria or brine shrimp. The transformation of effective concentrations of the chemicals, obtained from toxicity measurements, into percent of the saturation level in water is proposed as a first evaluation of potential hazard to aquatic systems. Simetryn was found to be the most hazardous s- triazine for all species tested.
No preview · Article · Jan 1995 · Environmental Toxicology and Chemistry
[Show abstract][Hide abstract] ABSTRACT: Vapour levels of metallic mercury in the atmosphere of an abandoned mercury mine and distillation plant at Abbadia S. Salvatore (Mount Amiata, Tuscany, Italy) were detected by means of the mercury accumulation rate in leaves of azaleas located in 100 sampling sites. The response of azalea leaves to a constant mercury concentration in the air (30 ng/L) was calibrated in the field, in relation to indoor conditions. No significant methylation of mercury was found to occur in spontaneous vegetation or contaminated azalea samples. The volatilization of mercury at different temperatures and the use of bioconcentrators to detect mercury vapours in contaminated areas is discussed.
[Show abstract][Hide abstract] ABSTRACT: A simple approach for ranking the leaching of pesticides from surface soil is presented and tentatively calibrated with field data from an agricultural area. The approach is based on the calculation of a leaching index indicating the proportion of active ingredient, with respect to the quantity applied, leaching from a soil model in a given time interval (one year). In the selected area, 85 wells tapping an unconfined aquifer were sampled for groundwater pesticide residue analysis, in order to explore the index region between leachers and nonleachers.
No preview · Article · Mar 1994 · Environmental Science and Pollution Research
[Show abstract][Hide abstract] ABSTRACT: Preliminary results on the concentration of aerobic, heterotrophic marine bacteria, and on its luminescent fraction in plated filters of coastal water samples, both under “clean” and polluted conditions, are reported. The feasibility of the application of such an approach in characterizing the integrity of marine environments, with the perspective of developing a water quality index, is discussed.
[Show abstract][Hide abstract] ABSTRACT: Concentrations of DDTs, HCHs and HCB in foliage have been used to evaluate the contamination levels of two African areas and Seychelles and Mauritius Islands. Physico-chemical properties in combination with environmental features play the most important role in the global distribution of chlorinated hydrocarbons. However past and present applications appear to be significant in determining the characteristics of the contamination pattern in different areas. Results are discussed in comparison to previous African data. Remarkable differences in contamination levels are evident among the areas considered. Log-Probit and Correspondence Factor Analyses are used for the characterization of the typical distribution pattern of each area. Relative differences in the composition of the pollutant mixture (HCHs dominance, different DDE/DDT ratios etc.) seem to indicate a “fingerprint” of the contamination for each geographical-economical homogeneous region.
[Show abstract][Hide abstract] ABSTRACT: Experimental data on the accumulation and release kinetics of azalea leaves exposed to a constant vapour level of mercury is reported. The accumulation of mercury appears to be irreversible, probably as a consequence of chemical transformation. Potential applications and implications on the biogeochemical cycle of mercury are discussed.
[Show abstract][Hide abstract] ABSTRACT: Plant biomass plays a significant role in the global environmental partitioning phenomena and plants are good indicators of tropospheric contamination levels by chlorinated hydrocarbons. In the present research 300 samples of plants were collected in 265 areas distributed worldwide and analyzed for HCB (hexachlorobenzene), Î±-HCH (hexachlorocyclohexane), Î³-HCH, p,pâ²-DDT,o,pâ²-DDT, and p,pâ²-DDE (degradation product of DDT). Global HCB distribution is strongly dependent on the temperature, the HCB being present mainly in samples from cold areas. The sum of DDTs show higher concentrations in samples from topical areas, while the sum of HCHs is higher in the plants from the Northern Hemisphere. These results are discussed, taking into account the role of physicochemical properties in determining the global distribution as well as the air age of the contamination.
Full-text · Article · Aug 1991 · Environmental Science and Technology
[Show abstract][Hide abstract] ABSTRACT: Levels of some chlorinated hydrocarbon residues (HCB, HCH isomers, p,p'-DDT and related compounds, PBC congeners) in lichen and moss from Kay Island, Ross Sea, Antarctica, are reported and compared with data from similar species collected on Antarctic Peninsula. The role of the cold remote areas in the global circulation of these contaminants is briefly discussed.
[Show abstract][Hide abstract] ABSTRACT: A simple fugacity-based model is presented describing the equilibrium and kinetics of uptake by leaves of hydrophobic organic chemicals in the vapor state from the atmosphere. A correlation is suggested for the leaf-air bioconcentration factor as a function of the chemicals' water-air and octanol-air partition coefficients and the leaf properties of air, water, and octanol-equivalent volume fractions. The octanol-air partition coefficient (which can be evaluated from the octanol-water and air-water partition coefficient) is suggested as the key partitioning descriptor for hydrophobic chemicals. A correlation for the leaf clearance rate constant is suggested in terms of two empirical leaf-specific transport parameters and the control-air partition coefficient.
Preview · Article · May 1991 · Environmental Science and Technology
[Show abstract][Hide abstract] ABSTRACT: Extensive survey data for butyltins are reported for Mediterranean coastal waters together with the first phenyltin concentrations from the region. Elevated levels of tributyltin (TBT) are reported for most marina/harbour waters. In the great majority of cases, the ‘no observable effect’ aqueous concentration of 20ng litre−1 is exceeded. The TBT concentrations encountered are comparable to those reported in a previous MEDPOL pilot survey. This questions the efficacy of current legislation in the Mediterranean. The movement of foreign vessels painted outside of the scope of legislation offers an explanation for this observation and endorses the need for region-wide control measures and enforcement. The Contracting Parties to the Barcelona Convention have recently agreed to adopt such control measures to protect the Mediterranean; these are described and discussed. Concerning triphenyltin, concentrations of 21–94 ng litre−1 are reported, with most of the compound associated with the particulate phase. The distribution in samples collected from marinas and in proximity to dry docks attributes the origin of the compound to antifouling paint leachates.
Full-text · Article · Jan 1991 · Marine Environmental Research