Phytostabilization potential of Erica australis L. and Nerium oleander L.: a comparative study in the Riotinto mining area (SW Spain).

Phytostabilization is a green, cost-effective technique for mine rehabilitation and ecological restoration. In this study, the phytostabilization capacity of Erica australis L. and Nerium oleander L. was assessed in the climatic and geochemical context of the Riotinto mining district, southwestern Spain, where both plant species colonize harsh substrates of mine wastes and contaminated river banks. In addition to tolerating extreme acidic conditions (up to pH 3.36 for E. australis), both species were found to grow on substrates very poor in bioavailable nutrients (e.g., N and P) and highly enriched with potentially phytotoxic elements (e.g., Cu, Cd, Pb, S). The selective root absorption of essential elements and the sequestration of potentially toxic elements in the root cortex are the main adaptations that allow the studied species to cope in very limiting edaphic environments. Being capable of a tight elemental homeostatic control and tolerating extreme acidic conditions, E. australis is the best candidate for use in phytostabilization programs, ideally to promote early stages of colonization, improve physical and chemical conditions of substrates and favor the establishing of less tolerant species, such as N. oleander.

Phytotoxicity of polymetallic mine wastes from southern Tuscany and Saxony.

Restoration potential of mine wastes or approaches to improve soil conditions and to ameliorate phytotoxicity on these sites may be simulated in standardized greenhouse experiments. Plants can be cultivated side by side on materials from different origins in dilution series with defined admixtures of certain aggregates. Mine wastes used in the present study originated from Fenice Capanne (FC, Tuscany, Italy) and Altenberg (ALT, Saxony, Germany). Tailings of the Italian site contain high concentrations of lead, zinc, arsenic and sulphur while tin, wolfram, molybdenum and lithium are highly elevated in the German mine waste. We tested growth responses of five crop species and analyzed concentrations of various metals and nutrients in the shoot to evaluate the toxicity of the FC mine waste and found oilseed rape being the most and corn the least resistant crop. Interestingly, oilseed rape accumulated seven times higher levels of lead than corn without showing adverse effects on productivity. In a subsequent comparison of FC and ALT mine waste, we cultivated different species of buckwheat (Fagopyrum spec.), a fast growing genus that evolved in mountain areas and that has been shown to be tolerant to low pH and high concentrations of metals. We found that the FC mine waste was more toxic than the ALT substrate in F. tataricum and F. esculentum. However, lower admixtures of FC material (10%) resulted in stronger growth reductions than higher proportions (25%) of the mine waste which was primarily related to the slightly lower pH and higher availability of essential metals due to the admixture of sand. These results confirm the importance of managing the soil chemical and physical characteristics of wastelands and call for the development of assisted reclamation to prepare sites for regular biomass production.

Stress responses of Erica andevalensis Cabezudo & Rivera plants induced by polluted water from Tinto River (SW Spain).

The effects of Tinto River water on Erica andevalensis growth, biochemical indicators and elemental concentration and distribution were investigated under laboratory conditions. High levels of toxic elements such as B, Fe and S and acidic pH characterized the river water. Plant analysis revealed that the concentration of Al, B, S and Fe increased in all plant organs reaching in some cases values in the toxicity range. Plants transferred into river water stopped growing and stress was manifested by plant water loss, increase in peroxidase activity and decrease of chlorophyll a concentration. Significant decreases of free amino acid concentration were found in shoots and roots of plants grown in diluted river water. The results indicated that Tinto River water acidity and its excess in soluble elements produced altogether severe alterations in roots affecting plant water and nutrient uptake and leading to the massive entry of some metals (e.g. Fe, Al) with toxic effects. Scanning-electron microscopy (cryoSEM and ESEM) observations showed that E. andevalensis had not exclusion mechanisms of Cu, Fe and S therefore it was not able to reduce translocation to aerial parts.

Natural and pre-treatments induced variability in the chemical composition and morphology of lichens and mosses selected for active monitoring of airborne elements.

To enhance the reliability of the moss and lichen transplant technique for active biomonitoring of trace metals in urban environments, we evaluated the natural variability in the chemical composition of the (epilithic and epiphytic) moss Hypnum cupressiforme and the epiphytic lichen Pseudevernia furfuracea from two reference areas in NE Italy. Green shoots of epilithic mosses and lobes of epiphytic lichens from larch branches showed rather homogenous composition and were selected for the exposure in nylon bags. As different physico-chemical pre-treatments are usually applied to selected cryptogamic material before its exposure, we also evaluated the effects of oven-drying at 120 degrees C for 24h, washing in 1N HNO3 solution, and in 0.5% NH4 oxalate solution at 85 degrees C for 15 h on the chemical composition and morphology of water-washed moss shoots and lichen lobes. Pre-treatments remarkably changed the chemical composition of selected materials but not their surface morphology.

Analysis of trace elements in bronchoalveolar lavage of patients with diffuse lung diseases.

Airborne trace elements are implicated in the etio-pathogenesis of a large number of pulmonary diseases. The aim of this study was to evaluate the reliability and effectiveness of direct determination of Cd, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn concentrations in bronchoalveolar lavage (BAL) samples from patients with sarcoidosis, idiopathic pulmonary fibrosis, and Langerhans cell histiocytosis and healthy (smoking and non-smoking) controls. A total of 44 individuals were recruited among sarcoidosis, idiopathic pulmonary fibrosis, and Langerhans cell histiocytosis patients and healthy (smoking and non-smoking) controls. Average Mn concentrations in BAL from patients were 45% lower than in controls (p < 0.01) and remarkable decreases in average concentrations of Cr, Ni and Zn were also found in BAL from patients with idiopathic pulmonary fibrosis and Langerhans cell histiocytosis. As these diseases are characterized by the enhanced activation of certain immunomodulatory cells and by generation of free radicals, the depressed Mn, Zn, Cr and Ni concentrations in BAL from patients may be due to oxidative stress. These preliminary results indicate that assessment of the elemental composition of BAL is a promising approach to study the pathogenesis of diffuse lung diseases and Langerhans cell histiocytosis.

Lichen and moss bags as monitoring devices in urban areas. Part II: trace element content in living and dead biomonitors and comparison with synthetic materials.

Lobes of the lichen Pseudevernia furfuracea (L.) Zopf and shoots of the moss Hypnum cupressiforme Hedw. were subjected to different treatments (water washing, oven drying, HNO3 washing, NH4-oxalate extraction) to assess the influence of vitality on accumulation efficiency, during a 6-week exposure in bags in two Italian cities, Trieste and Naples. No trend emerged between treatments, in terms of accumulation ability, for major and trace elements. Only water-washed lichens showed an increased C and N content after exposure in both cities. Element concentrations generally reached higher values in mosses than in lichens, especially for Al, Fe, and Zn (both cities), and for Cu, Mg and Na (Naples). Surface development strongly influenced accumulation capacity of the biomonitors. Quartzose and cation exchange filters revealed, on a weight basis, a poor performance. In urban environments, surface interception of atmospheric particulate seems to play a major role in accumulation, irrespective of organism vitality.

n-TiO2 and CdCl2 co-exposure to titanium dioxide nanoparticles and cadmium: Genomic, DNA and chromosomal damage evaluation in the marine fish European sea bass (Dicentrarchus labrax).

Due to the large production and growing use of titanium dioxide nanoparticles (n-TiO2), their release in the marine environment and their potential interaction with existing toxic contaminants represent a growing concern for biota. Different end-points of genotoxicity were investigated in the European sea bass Dicentrarchus labrax exposed to n-TiO2 (1mgL(-1)) either alone and combined with CdCl2 (0.1mgL(-1)) for 7 days. DNA primary damage (comet assay), apoptotic cells (diffusion assay), occurrence of micronuclei and nuclear abnormalities (cytome assay) were assessed in peripheral erythrocytes and genomic stability (random amplified polymorphism DNA-PCR, RAPD assay) in muscle tissue. Results showed that genome template stability was reduced after CdCl2 and n-TiO2 exposure. Exposure to n-TiO2 alone was responsible for chromosomal alteration but ineffective in terms of DNA damage; while the opposite was observed in CdCl2 exposed specimens. Co-exposure apparently prevents the chromosomal damage and leads to a partial recovery of the genome template stability.

Oak leaves as accumulators of airborne elements in an area with geochemical and geothermal anomalies.

The Colline Metallifere (Tuscany) was a major Italian mining district (FeS2, Ag, Cu, Pb, Zn) for centuries, and in the last fifty years it has become the most important area for the exploitation of geothermal resources. Leaves of the widespread oak Quercus pubescens and surface soils were collected from 90 sampling sites in the area and their elemental composition was compared. The results showed that the composition of oak leaves was not significantly affected by the presence of mineral deposits (metal sulphide ores) or soils with high concentrations of Cr, Mg, and Ni (ultramafic). Arsenic was the only element showing higher concentrations in leaves from sites with deposits of metal sulphide ores or As-polluted soils around abandoned smelting plants. Compared to the composition of epiphytic lichens andepigeic mosses from the same sites in the Colline Metallifere, the elemental composition of Q. pubescens leaves was less affected by element contributions from adsorbed soil particles. It was thus easier to evaluate atmospheric inputs of elements in oak leaves than in cryptogams.

Biomonitoring of airborne metals in urban environments: new tracers of vehicle emission, in place of lead.

Samples of Quercus ilex leaves and of the inhalable fraction of atmospheric particulate (PM(10)) were collected along a busy road and in a park in Florence (Italy). Quantitative comparisons and correlations of element concentrations in PM(10) collected by air samplers at two sites showed that Ba, Cu, Fe, Mn, Pb and Zn were the main metal pollutants emitted by vehicles in Florence. Very similar results were obtained by the analysis of Q. ilex leaves which were found to accumulate airborne metals as a function of the exposure time (i.e. their age). One-year-old leaves showed the highest rate of metal accumulation. Our results show that the progressive phasing-out of leaded petrol in Italy has resulted in a decrease of about 20% per year in the Pb concentrations in PM(10). Both PM(10) and Q. ilex analysis singled out Ba and Zn as valid tracers of automotive traffic instead of Pb.

Trace elements in striped dolphins (Stenella coeruleoalba) from the western Mediterranean.

Tissues obtained from Stenella coeruleoalba stranded along the Spanish and Italian Mediterranean coasts from 1987 to 1994 were analysed for cadmium (Cd), copper (Cu), mercury (Hg), selenium (Se) and zinc (Zn). The age, length and weight of the dolphins were recorded. Hg levels were also assayed in skin biopsies from dolphins of the same species in the waters off northeastern Spain and in the Tyrrhenian and Ligurian Seas. Levels of all elements differed in muscle of stranded dolphins from the two areas. Hg was higher in tissues from animals stranded on the Italian coasts and in skin biopsies obtained in the Tyrrhenian and Ligurian Seas, than in the respective Spanish samples. This is probably related to Hg pollution from the natural weathering of cinnabar ores in central Italy. Se and Cd levels had similar accumulation patterns to those of Hg. Accumulation of Hg and Se is explained by the existence of a detoxification pathway involving both elements, however the reason for the similar Cd trend is unclear. Geographical differences in the accumulation pattern of these elements may reflect the existence of two different populations of Stenella coeruleoalba in the western Mediterranean.

Mosses and lichens as biomonitors of trace metals. A comparison study on Hypnum cupressiforme and Parmelia caperata in a former mining district in Italy.

Samples of the moss Hypnum cupressiforme and the epiphytic lichen Parmelia, caperata were collected during the summer of 1999 in an area (Colline Metallifere, central Italy) intensively exploited in the past for metals (Cu, Fe, Pb, Zn) and currently for geothermal resources. Lichens were more sensitive than mosses to emissions of S compounds near geothermal fields and abandoned sulphide ore smelting plants. Comparison of elemental compositions of the two cryptogamic species from the same sampling sites showed significantly higher concentrations of lithophile elements (Al, Cr, Fe, Mn, Ni, Ti) in the moss and atmophile elements (Hg, Cd. Pb, Cu, V, Zn) in the lichen. Patterns of bioaccumulation of elements throughout the study area were quite similar for widespread pollutants such as S, B, As, Zn, Cr and Ni, but the lichen and the moss showed different distribution patterns of Hg, Cd and other elements subject to long-range atmospheric transport. These results are due to differences in the morphology and ecophysiology of mosses and lichens and indicate that these organisms cannot be used interchangeably as biomonitors of metals in areas with mineral deposits.

Concentrations of major elements and mercury in unstimulated human saliva.

The aim of this study was a preliminary assessment of a possible role of human saliva in the diagnosis of some physiological and pathological changes in oral and body functions. Reliable procedures for collection and analysis of samples were established in order to assess total concentrations of Ca, K, Mg, Na, P, and Hg in whole unstimulated saliva. Possible relationships between element concentrations and sex, age, smoking, illness conditions, or side effects resulting from the use of drugs were investigated. The effects of stimulated or unstimulated collection procedures, dental prosthesis, and amalgam fillings were also evaluated. Total concentrations of major cations and Hg in whole saliva from 33 healthy adults living in the Siena district showed a coefficient of variation ranging from 11% (P) to 53% (Na) and average values were in the same range of those previously reported for unstimulated saliva. Healthy males had significantly higher concentrations of K, Na, P, and Na/K, Na/Ca, Na/Mg, and Na/P values than females. Age, smoking, dental prosthesis, and amalgam fillings had no significant effects on the concentrations of major elements. On the contrary, concentrations of Hg were positively correlated to the number of amalgam fillings and increased at a rate of about 1.9 microg/L for each filling. No correlations were found between Hg concentrations and those of major elements. Comparisons with literature data showed a different composition (particularly for Na and Hg concentrations) between unstimulated and stimulated saliva. Samples from patients affected by idiopathic pulmonary fibrosis had significantly higher concentrations of K and the maximum value was measured in a patient affected by acute pulmonary edema. This increase was likely the result of pharmacological treatments with tricyclic antidepressants and/or saline solutions. Data reported in this study, although preliminary, contribute to the assessment of levels of major cations (some of them very little investigated) and Hg in whole unstimulated human saliva and provides consistent support for further research on the possible use of this easy accessible matrix as a diagnostic tool of body function changes.

Improved biomonitoring of airborne contaminants by combined use of holm oak leaves and epiphytic moss.

Concentrations of 12 elements (Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn) and 16 EPA-listed PAHs were detected in Quercus ilex leaves and the epiphytic moss Leptodon smithii collected at urban, periurban and extraurban holm oak stands, in two Italian Regions (Campania and Tuscany). Levels of environmental contaminants were generally higher in leaves and moss from urban areas than periurban and extraurban ones and samples from Campania had the highest PAH content. The epiphytic moss accumulated higher concentrations of trace elements than leaves and the latter showed a higher accumulation capability for PAHs, especially for those with low molecular weight. The different bioaccumulation in leaves and moss were explained in terms of their distinctive morphological and ecophysiological characteristics. The combined approach seems a promising tool for the monitoring of a wide range of pollutants in Mediterranean urban and extraurban environments.

Bags with oven-dried moss for the active monitoring of airborne trace elements in urban areas.

To define a harmonized methodology for the use of moss and lichen bags as active monitoring devices of airborne trace elements in urban areas, we evaluated the element accumulation in bags exposed in Naples in different spring weather conditions for 6- and 12-weeks. Three different pre-exposure treatments were applied to moss and lichen materials: water-washing, acid-washing and oven-drying. During the different exposure periods in the Naples urban environment the moss accumulated always higher amounts of elements (except Hg) than lichens and the element accumulation increased during wetter weather and higher PM(10) conditions. The oven pre-treatment did not substantially modify the morphology and element composition of moss and the exposure in bags of this material for 6-weeks was sufficient to detect the pattern of airborne trace elements.

Multiresponse biomarker evaluation of interactions between methylmercury and Arochlor 1260 in quail.

The single and combined effects of methylmercury and Arochlor 1260 were investigated in experimental quail treated chronically with the two compounds at low and high doses. A series of metabolic and biochemical biomarkers were evaluated together with mercury and PCB accumulation to pinpoint the effects of treatment with one or both chemicals. Methylmercury alone was associated with a decrease in serum cholesterol. Less PCBs were accumulated in tissues when Arochlor 1260 was combined with methylmercury than when the former was administered alone. Liver monooxygenase (MFO) activity was depressed 50% more in the presence of methylmercury than with Arochlor 1260 alone. Single or combined treatment with high doses of the two compounds resulted in similar degrees of DNA damage. This approach was found to provide a good picture of the interaction between environmental contaminants.

Baseline concentrations of elements in the Antarctic macrolichen Umbilicaria decussata

Total concentrations of major and trace elements were determined in samples of the epilithic lichen Umbilicaria decussata from 24 ice-free areas in coastal Victoria Land (Antarctica). Overall average concentrations of trace elements except Cd were the lowest ever reported for lichens of the genus Umbilicaria. Specifically, the mean level of Pb in lichens from granitic rocks (0.46 +/- 0.18 microg g(-1) dry wt) was more than four times lower than the lowest record in Arctic lichens. No impact of local human activities was detected, but the elemental composition of U. decussata was affected by entrapment of soil or rock dust particles and probably by uptake of soluble elements from substrate. Relationships between elements and their distribution patterns in the study area indicated that the marine environment is the main source of major ions and perhaps of Cd in lichens. Accumulation of P was detected in samples from coastal sites frequented by seabirds. Although the present results can be taken as baseline levels of major and trace elements in Antarctic U. decussata from substrates with very different geochemical features, further research is necessary to evaluate the relative element contribution from each substrate with respect to those from snow, marine aerosol, salt encrustations and guano.