RESUMO
The results of a survey aimed at investigating whether NO2 and NH3 emitted by road traffic can influence lichen diversity, lichen vitality and the accumulation of nitrogen in lichen thalli are reported. For this purpose, distance from a highway in a rural environment of central Italy was regarded as the main parameter to check this hypothesis. The results of the present survey indicated that road traffic is not a relevant source of NH3. On the other hand, NO2 concentrations, although rather low, were negatively correlated with distance from the highway according to a typical logarithmic function. No association between NO2 concentrations and the diversity of epiphytic lichens was found, probably because of the low NO2 values measured. Also bark properties were not influenced by distance from the highway. Accumulation of nitrogen, reduction in the content of chlorophyll a, chlorophyll b and total carotenoids were found in transplanted thalli of Evernia prunastri, but NO2 was not responsible for these changes, which were probably caused by applications of N-based fertilizers.
Assuntos
Poluentes Atmosféricos/toxicidade , Amônia/toxicidade , Líquens/fisiologia , Dióxido de Nitrogênio/toxicidade , Emissões de Veículos/toxicidade , Biodiversidade , Carotenoides/análise , Clorofila/análise , Clorofila A , Monitoramento Ambiental/métodos , Geografia , Itália , Líquens/química , Casca de Planta/química , ÁrvoresRESUMO
Previously, the unusual ion composition [M + Fe - 5H]2- had been proposed as the major species observed when a gamma-carboxy glutamate-containing glyco-peptide was analyzed with electrospray ionization in the negative ionization mode. The sequence assignment of this highly post-translationally modified peptide was based on the mass analysis using a quadrupole ion trap together with information from both Edman and DNA sequencing. Because there was little precedent for the loss of five protons from a ferric cationized peptide, we utilized Fourier transform mass spectrometry accurate mass and tandem mass spectrometry analyses to verify the peptide ion composition.
Assuntos
Peptídeos/química , Alquilação , Aminoácidos/análise , Compostos Férricos , Análise de Fourier , Cromatografia Gasosa-Espectrometria de Massas , Oxirredução , PrótonsRESUMO
A field study, organised, coordinated and conducted under the responsibility of the United Nations Environment Programme (UNEP), took place in Kosovo in November 2000 to evaluate the level of depleted uranium (DU) released into the environment by the use of DU ammunition during the 1999 conflict. Representatives of six different scientific organisations took part in the mission and a total of approximately 350 samples were collected. During this field mission, the Italian National Environmental Protection Agency (ANPA) collected water, soil, lichen and tree bark samples from different sites. The samples were analysed by alpha-spectroscopy and in some cases by inductively coupled plasma-source mass spectrometry (ICP-MS). The 234U/238U and 235U/238U activity concentration ratios were used to distinguish natural from anthropogenic uranium. This paper reports the results obtained on these samples. All water samples had very low concentrations of uranium (much below the average concentration of drinking water in Europe). The surface soil samples showed a very large variability in uranium activity concentration, namely from approximately 20 Bq kg(-1) (environmental natural uranium) to approximately 2.3 x 10(5) Bq kg(-1) (approximately 18000 mg kg(-1) of depleted uranium), with concentrations above environmental levels always due to DU. The uranium isotope measurements refer to soil samples collected at places where DU ammunition had been fired; this variability indicates that the impact of DU ammunitions is very site-specific, reflecting both the physical conditions at the time of the impact of the DU ammunition and any physical and chemical alteration which occurred since then. The results on tree barks and lichens indicated the presence of DU in all cases, showing their usefulness as sensitive qualitative bio-indicators for the presence of DU dusts or aerosols formed at the time the DU ammunition had hit a hard target. This result is particularly interesting considering that at some sites, which had been hit by DU ammunition, no DU ground contamination could be detected.
Assuntos
Urânio/análise , Guerra , Poluentes Radioativos da Água/análise , Abastecimento de Água , Aerossóis , Animais , Monitoramento Ambiental , Humanos , Líquens/química , Espectrometria de Massas , Poluentes do Solo/análise , Árvores/química , Urânio/efeitos adversos , IugosláviaRESUMO
The United Nations Environment Programme (UNEP) has performed a field survey at 11 sites located in Kosovo, where depleted uranium (DU) ammunitions were used by the North Atlantic Treaty Organization (NATO) during the last Balkans conflict (1999). Soil sampling was performed to assess the spread of DU ground contamination around and within the NATO target sites and the migration of DU along the soil profile. The 234U/238U and 235U/238U activity concentration ratios have been used as an indicator of natural against anthropogenic sources of uranium. The results show that levels of 238U activity concentrations in soils above 100 Bq x kg(-1) can be considered a 'tracer' of the presence of DU in soils. The results also indicate that detectable ground surface contamination by DU is limited to areas within a few metres from localised points of concentrated contamination caused by penetrator impacts. Vertical distribution of DU along the soil profile is measurable up to a depth of 10-20 cm. This latter aspect is of particular relevance for the potential risk of future contamination of groundwater.
Assuntos
Poluentes Radioativos do Solo/análise , Urânio/análise , Animais , Monitoramento Ambiental , Humanos , Urânio/efeitos adversos , Guerra , Abastecimento de Água , IugosláviaRESUMO
Sequential separation of 210Pb and 21OPo in environmental samples allows the determination of these naturally occurring radionuclides with good chemical yields and low detection limits. After sample mineralization, part of the leaching solution is used for 210Po determination which does not require any further treatment and essentially quantitative recoveries are obtained, using a standard 209Po tracer. The remaining part of the leaching solution is used for 210Pb determination. Starting from 3 g sediment (30 l water), the lower limits of detection of the method are 1.4 Bq kg(-1) (0.14 mBq l(-1)) for 210Pb and 0.25 Bq kg(-1) (0.016 mBq l(-1)) for 21OPo. The procedure has been checked by analysing two certified reference materials, supplied by IAEA, and reliable results have been obtained.