1,720,983 research outputs found
Toxic trace elements and organic compounds in the ambient air of Kabul, Afghanistan
No full textTo assess the ambient air quality in Kabul, we measured the contents in tree bark samples of 17 chemical elements by ICP–MS, polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) by GC–MS, polychlorinated biphenyls (PCBs) by GC–ECD and polycyclic aromatic hydrocarbons (PAHs) by HPLC. While there were rather high levels of sulfur (up to 2277 μg/g), the heavy element contents were rather low (i.e. Pb was in the range 3.12–5.00 μg/g), even though a slight peak value was recorded in the area of most intense traffic (Pb up to 13.91 μg/g). Slight traces of organohalogen compounds, i.e. PCBs and PCDD/Fs, were detected (ΣPCBs=1.184–6.318 ng/g; ΣPCDD/Fs=1.42–2.38 pg/g). Highly chlorinated congeners, i.e. OCDD/Fs and penta-, hexa- and hepta-CBs, dominated the profiles of these compounds. Only three- and four-ringed PAH compounds were detected, but at very low levels comparable with the natural background. The slightly anomalous trace element values and the profiles of PCDD/Fs and PAHs determined in the bark samples suggest a close relationship with emissions from automotive traffic and the domestic burning of wood and fossil fuels. The presence of distinct but unimportant PCB emission sources can also be inferred
Exploring distribution of potentially toxic elements in soil profiles to assess the geochemical background and contamination extent in soils of a metallurgical and industrial area in Kosovo
Full text linkThis geochemical study explored the distribution of potentially toxic elements (PTEs), such as As, Cd, Co, Cr, Cu, Ni, Pb, Sb, Tl, U, and Zn, along soil profiles of a metallurgical and industrial area in Kosovo, with the aim of assessing geochemical background and contamination threshold of PTEs in soil, and defining surface and vertical level and extent of soil contamination by PTEs. The geochemical background was assessed by exploratory data analysis of PTE concentrations in soil profiles. The upper limit of geochemical background (contamination threshold) was used as reference value to calculate the single pollution index and establish the PTE contamination level. Cadmium, Pb, Sb, Zn were the primary soil contaminants and As, Cu, Tl the secondary ones. The main sources of soil contaminants were the Zvecan smelter for Pb, Sb, As, Cu, Tl, and the Trepca industrial complex for Cd and Zn. The highest levels of Pb and Sb contamination were found up to depths between 30 and 60 cm in soil profiles within 5 km north and south-east of the Zvecan smelter. Contamination by Pb and Sb decreased with depth and affected the whole thickness of soil profiles closer the smelter. Cadmium and Zn contamination declined with distance from the Trepca industrial complex and decreased with depth, extending down to depths of 40–90 cm and 30–70 cm, respectively. Anomalous natural concentrations of Co, Cr, and Ni were found in soils collected in the northern part of the study area, where the geology consists mainly of ultrabasic and basic magmatic rocks
Il drenaggio acido in natura e la rilevanza ambientale del drenaggio acido di miniera in Toscana meridionale
No full textIl drenaggio acido è un processo naturale che coinvolge, a scala locale, le sfere geochimiche di superficie, in particolare l’idrosfera. Tuttavia, numerose attività antropiche di tipo industriale, tra cui principalmente quelle connesse con la coltivazione delle miniere ed il trattamento del minerale, possono amplificare enormemente il fenomeno del drenaggio acido. Ciò è dovuto al fatto che i lavori minerari in sotterraneo e l’accumulo in discariche a cielo aperto degli scarti della lavorazione del minerale comportano un notevole aumento delle quantità di solfuri esposti all’attacco delle acque ossigenate di superficie. Data la sua specificità, il drenaggio acido legato all’attività mineraria s.l. è definito comunemente drenaggio acido di miniera (Acid Mine Drainage o AMD), e rappresenta un serio problema ambientale in aree minerarie sia attive che abbandonate.
In considerazione delle implicanze ambientali legate all’AMD, il presente lavoro si propone, da un lato, di illustrare i principali lineamenti ed aspetti della chimica del drenaggio acido di miniera e, dall’altro, di rilevare e caratterizzare il fenomeno in oggetto nel distretto minerario delle Colline Metallifere in Toscana meridionale
Uranium contents and 235U/238U atom ratios in soil and earthworms in western Kosovo after the 1999 war
No full textThe uranium content and 235U/238U atom ratio were determined in soils and earthworms of an area of Kosovo (Djakovica garrison), heavily shelled with depleted uranium (DU) ammunition during the 1999 war. The aim of the study was to reconstruct the small-scale distribution of uranium and assess the influence of the DU added to the surface environment. The total uranium concentration and the 235U/238U ratio of topsoils showed great variability and were inversely correlated. The highest uranium levels (up to 31.47 mg/kg) and lowest 235U/238U ratios (minimum 0.002147) were measured in topsoils collected inside, or very close to, the clusters of DU penetrator holes. Regarding the fractionation of uranium in the surface soils, the uranium concentrations in the soluble and exchangeable fractions increased as the total uranium concentration of the topsoils increased. High and rather uniform percentage contents of uranium (24–36%) were associated with the poorly crystalline iron oxide phases of soils. In the U-enriched soils the elevated levels of the element were probably due to the presence of very small, unevenly distributed oxidized DU particles. The total uranium concentration in earthworms was in the range 0.142–0.656 mg/kg, with the highest concentrations in Lumbricus terrestris. The juveniles of all three studied species seemed to accumulate uranium more than adults, probably due to age-related differences in metabolism. The 235U/238U ratio in the earthworms was variable (0.005241–0.007266) and independent of both the total uranium contents in soils and the absolute uranium levels in the animals. Bioconcentration was greater at lower U concentrations in soil, probably due to an increasing rate of elimination of uranium by the earthworms as the soil contents of the element increase. The results of this study clearly indicate that DU was added to the soil of the study area. Nevertheless, the phenomenon was very limited spatially and the total uranium concentrations fell within the natural range of the element in soils. Moreover, the absolute uranium concentrations indicate that there was no contamination of the earthworm species studied
The Firenze Sheet of the geochemical map of Italy: explanatory notes
No full textThe paper describes and discusses the distribution of toxic and potentially toxic elements such as cobalt, lead and vanadium, in stream sediments of the Sheet NK 32-3 Firenze
The Roma Sheet of the geochemical map of Italy: explanatory notes
No full textThe paper describes and discusses the distribution of toxic and potentially toxic elements such as cobalt, chromium, lead and vanadium, in stream sediments of the Sheet NK 33-7 Roma
The Terni Sheet of the geochemical map of Italy: explanatory notes
No full textThe paper describes and discusses the distribution of toxic and potentially toxic elements such as cobalt, lead and vanadium, in stream sediments of the Sheet NK 33-4 Terni
The Grosseto Sheet of the geochemical map of Italy: explanatory notes
No full textThe paper describes and discusses the distribution of toxic and potentially toxic elements such as cobalt, lead and vanadium, in stream sediments of the Sheet NK 32-6 Grosseto
Utilizzo di fanghi di depurazione in agricoltura: effetti a breve termine sulle concentrazioni di metalli pesanti nel mais (Zea mays L.)
No full textGeochimica dei suoli agricoli interessati dall’applicazione di fanghi di depurazione: un caso studio nel comune di Pitigliano (GR)
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