Application of lead stable isotopes to the Guadiamar Aquifer study after the mine tailings spill in Aznalcollar (SW Spain) (original) (raw)
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Journal of Geochemical Exploration, 2011
The isotopic signature of geogenic and anthropogenic materials, in combination with concentration data for pollutants, can help trace the origin and the extent of contamination in the environment. This approach is particularly effective if naturally occurring and anthropogenically introduced metals have different isotopic ratios. Lead isotope analysis on soils from 7 profiles (1 m depth) and on groundwaters from 8 wells have been used to determine the impact of human activities on the surface environment of Domizio-Flegreo Littoral. Result obtained show that in sub-rural areas the isotopic composition of the samples collected along the soil profiles of Domizio-Flegreo Littoral is likely mostly controlled by the nature of the parent geologic material (natural) while in more urbanized areas (Giugliano) Pb isotopic composition in superficial soils is mostly influenced by anthropic sources such as motor vehicles. Lead isotopic ratios in groundwaters also show that the use of pesticides and, probably, the influence of aerosols and the presence of illegal waste disposal can influence water quality.
Anthropocene, 2023
Legacy pollution research has established that over the past 3000 years, mining and metallurgical activities have resulted in widespread deposition of lead (Pb) pollution. However, there is still a limited understanding of how humans have impacted the long-term cycling of Pb in the environment. We present a 4,000-year lake sediment Pb isotope record from Laguna Roya, northwestern Iberia, that identifies and quantifies the predominant sources of atmospheric Pb pollution. For the first time, Pb isotopic compositions of ancient slag samples dated (~600 BCE-200 CE) from a mining district in the southwest of the Iberian Peninsula are compared to Pb isotope ratios of Pb pollution deposited contemporaneously in lake sediments. In addition, literature Pb isotope ratios of ores from mining regions throughout Iberia are compared with those of leaded gasoline and coal to identify additional sources of anthropogenic Pb. Deposition of atmospheric Pb pollution begins after 950 BCE, and until 1750 CE, the Pb isotopic composition most resembles the southwestern slag deposits, containing a mixture of Pb ores from southeast Iberia (up to 36%) and southwest Iberia (~74%). Between 1750 and 1960 CE, Pb pollution is attributed to Pb mining in southcentral Iberia. After 1960 CE, the dominant Pb pollution source (~85%) is again metal refining in southwestern Iberia, and only ~15% is from leaded gasoline. Provenance and reconstruction of the temporal and spatial distribution of legacy Pb pollution further our understanding of how humans have affected the biogeochemical cycle of this toxic element in the environment over time.
Ciencias Marinas
This article discuss, using sediment samples from the Ria of Ferrol, the need for a better understanding of the biogeochemical cycle of lead in the Galician rias which, until now, was based on differing methodologies mainly applied to the biota in only few areas of the most important rias from a socioeconomic point of view. Thirty-five samples of superficial sediment were analysed for lead (in the < 63 µm and total fractions) and opal percentage and organic carbon in the total. An analytical method is proposed employing ETAAS, whereby the sediment is introduced directly as a slurry together with the optimised amount of chemical modifiers. The accuracy of the method was checked by means of a certified reference material, obtaining a sensitivity of 2.72 µg g-1 Pb with an RSD of 5.9%. Values of lead in the superficial sediment of the Ria of Ferrol ranged from 13.5 to 159.1 µg g-1 for the fraction < 63 µm, and from 12.1 to 142.5 µg g-1 for the total fraction. The distribution does not follow a decreasing trend from the innermost part of the ria, as may have been expected, but rather the maximum values were found in the vicinity of the harbour area in the middle ria, indicating that rias behave as a lead deposition barrier avoiding the export of the metal to the open sea. Lead dispersion is mainly controlled by the tidal currents, given its lowest concentrations in the zones of strongest current, and also by the plankton, following the relationship obtained [Pb] = 48 [opal] + 16. A baseline lead concentration of 18.2 µg g-1 was obtained for the fraction < 63 µm using core samples dated at 3745 ± 70 years before present. Applying this background values, the lead enrichment in the Ria of Ferrol is classified from moderate to considerable.
Biogeochemical Investigations at Watershed, Landscape, and Regional Scales, 1998
Variations in Pb concentration in lake sediments reflect changes in the fluxes of this element in the• past. A sediment core from a lake in the Pyrenees (Lake Redo at 2,240 m a.s.L, N_E Spain) was studied, with the aim of reconstructing pastenvironmenial and climatic conditions in the lake and its catchment area. The core was dated usii1g both 210 Pb and 14 C. A surface peak of Pb concentration, which was about 10 tim~s higher than the background level, was found. This peak is attributed to mining activities since the begioping of this century. Although Pb pollution due to the combustion of gasoline is expected to be present, no evidence can be deduced from Pb isotope ratios of sediment due to the masking effect of Pb from mines. A second peak appeared in a deeper layer, with a maximum Pb concentration of about 17 times higher than the background level. The origin of this peak is unclear. All evidence suggests that the ancient peak is due to mining operations in the central Pyrenees area, which were not documented historically.
Water, Air, & Soil …, 2011
Heavy metals and some major element concentrations were investigated in overbank sediments and stream bed sediments of the ephemeral Beal wadi creek in the Cartagena-La Union mining district (SE Spain). Two vertical sediment profiles were extracted and the chemical and mineralogical compositions were both investigated by X-ray fluorescence and X-ray diffraction. Geochemical variations in vertical profiles of these two kinds of sediments allow observing noticeable heavy metals pollution (especially Fe, Pb, and Zn) in both kind of sediments but especially in the overbank sediments (reaching values of approximately 13% Fe, 6% Pb, and 6% Zn). A single extraction (DIN 38414-S4 leaching test) was made to observe the transfer of metals from solids to liquid phase. Pb, Zn, Cu, and Cd contents surpass the leaching values established by the DIN 38414-S4 limits established by Spanish legislation to consider these wastes as hazardous wastes. Geochemical comparison between leaching behavior of the two types of sediments reveals a major ability of overbank sediments in transferring heavy metals to the water flow.
Journal of Geochemical Exploration, 2014
This paper presents the results of a study concerning the total and extractable concentrations of eight elements (As, Cd, Cr, Cu, Ni, Pb, Se and Zn) in soils and sediments from La Union mine (Toledo province, Castilla-La Mancha region, central Spain). It also presents the extent of the heavy metal contamination produced by the mining activities. Our results show that the study area can be considered as a heavily polluted site as consequence of the mining process carried out locally. This is demonstrated by the total concentrations of all studied elements, which are much higher than the World's and the Castilla-La Mancha's averages for soils. The elements that present the highest concentrations (total and extractable) are zinc and lead. Sediments show higher mean total concentrations than soils for all the studied elements. They also show the highest extractable concentrations due to the influence of the stream in the weathering of this type of materials. The areas affected by high concentrations of arsenic and heavy metals depend on the studied element, reaching the maximum extension and importance for lead and zinc. In the study area, the environmental damage can be increased by the low pH obtained since it implies an increase in the mobility of most of the studied elements.
Journal of Geochemical Exploration, 2009
About a century of exploitation of the galena-arsenopyrite deposit of Baccu Locci in Sardinia (Italy) has caused a severe, persistent arsenic contamination that extends downstream from the mine for several kilometres. Differently from As, the contamination of lead in surface waters is only localised in the upper part of the mine despite very high Pb concentrations in geologic materials (waste rocks, tailings, stream sediments, soils) over the whole Baccu Locci stream catchment. The aqueous and solid speciation of Pb in various environmental media of the Baccu Locci system was determined by means of a combined analytical (ICP-MS, SEM-EDX, TEM-EDX, chemical extraction) and thermodynamic approach (PHREEQC). The study has pointed out that relatively little Pb (up to 30 µg/L) is initially released to surface waters (pH = 7-8, Eh = 0.4-0.6 V) very rapidly due to dissolution of anglesite that is the first product of galena oxidation. Subsequently, Pb is removed (down to 0.6 µg/L) by probable sorption onto hydrous ferric oxides (e.g. ferrihydrite) and/or possible precipitation of Ascontaining plumbojarosite that is the main secondary Pb-bearing phase in stream sediments/tailings along the Baccu Locci stream course. The latter hypothesis is controversial since it is reported from the literature that plumbojarosite is formed under acidic conditions, although there is contrary field evidence as well. Bearing in mind the uncertainties introduced from thermodynamic and analytical data, the solubility calculations indicate strong undersaturation of surface waters with respect to plumbojarosite (SI: −19.9 to − 3.7). On the contrary arsenatian plumbojarosite is at or close to saturation (SI: −0.6 to 3.2) in most surface waters and beudantite is clearly above saturation (SI: 4.1 to 12.7). This suggests that the incorporation of As might increase the stability of plumbojarosite, extending it up to near-neutral conditions. As a consequence, Pb is prevented from being released downstream to surface waters, and dissolved Pb concentrations remain definitely below the Italian and WHO limits for drinking waters (50 µg/L and 10 µg/L, respectively).
Lead isotopes in environmental sciences: A review
Environment International, 2008
Lead (Pb) isotopic analyses proved to be a very efficient tool for tracing the sources of local and global Pb pollution. This review presents an overview of literature published on the use of Pb isotopic analyses of different environmental matrices (atmospheric aerosols, lichens, tree rings, peat deposits, lake, stream, marine sediments, soils, etc.). In order to gain more insight, the isotopic compositions of major sources of Pb in the environment as determined by several authors are described in detail. These include, above all, the former use of leaded gasoline, coal combustion, industrial activities (e.g., metallurgy) and waste incineration. Furthermore, this review summarises analytical techniques (especially ICP-MS) used for the determination of Pb isotopes in environmental samples.