Pb isotope ratios of lake sediments in West Greenland: inferences on pollution sources (original) (raw)
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Stable lead isotope ratios in arctic aerosols: evidence for the origin of arctic air pollution
Atmospheric Environment (1967)
The isotopic composition of aerosol lead in the polar region potentially contains information on the origin of Arctic pollution which will complement that from meteorological and trace elemental composition studies. Weekly samples of atmospheric aerosols were collected at three locations in the Canadian Arctic from mid-1983 to mid-1984. They were analyzed for elemental composition and stable lead isotope ratios (Pb 206/207). High crustal enrichment factors confirmed that the majority of samples contained lead of anthropogenic origin. Pb 206/207 ratios were very uniform over time and between sites, suggesting a common origin of lead pollution in the Canadian Arctic. The mean isotope ratios at the Alert and Mould Bay stations were 1.160~0.010 and 1.161+0.006, respectively (samples from a third site at Igloolik were eiidently contaminated by local sources). A small nun&r of samples from Spitsbergen, taken durine flow medominantlv out of the northern U.S.S.R.. were found to have a similar mean Pb 206/207 ratio .d 1 of 1.154~0.006. From published lead isotope analyses of Soviet lead-bearing ores, we would ex&t a mean isotope ratio in industrial and vehicular emissions in the U.S.S.R. of around 1.158. Contributions to Arctic lead pollution from the U.S. and western Canadian sources can probably be ruled out, as they have significantly higher Pb 206/207 ratios. Similarly, emissions from northern Canadian and Kola Peninsula smelters can be disregarded, as they appear to have low isotope ratios. Eastern Canadian automotive lead aerosol contained only marginally lower Pb 206/207 ratios than in the Arctic, but meteorological studies argue against this region being a major source area for Arctic pollution. Scant European data suggest that European Pb emissions generally have lower isotope ratios than the Arctic samples. However, more data in Eurasia are needed before apportionments of Arctic Pb between sources within the region can be made.
Size-segregated (PM 10) aerosol samples have been systematically collected at Ny-A ˚ lesund (Svalbard Islands, Norwegian Arctic) during the spring and summer 2010 and analysed for elemental composition (major and trace elements, rare earth elements) and stable lead isotope ratios (206 Pb/ 207 Pb, 208 Pb/ 207 Pb). The analysis of the obtained dataset provided valuable information on the sources and long-range transport processes of atmospheric particulate and associated contaminants reaching the Arc-tic. In particular, a seasonal pattern was evident for Ba, Cd, Mn, Mo, Pb (p value B0.05), showing a higher input of elements related to anthropogenic emissions in spring compared to summer. Pb isotope ratios clearly showed that the geographic source of the anthropogenic input is subjected to a seasonal shift with an increased contribution of air masses coming from the north Eurasia during spring, and air masses coming from North America during summer. This finding was further corroborated by back-trajectory analysis. Finally, the analysis of the rare earth elements revealed an uniform pattern, without significant differences between the two seasons.
Rendiconti Lincei, 2016
Size-segregated (PM 10) aerosol samples have been systematically collected at Ny-Å lesund (Svalbard Islands, Norwegian Arctic) during the spring and summer 2010 and analysed for elemental composition (major and trace elements, rare earth elements) and stable lead isotope ratios (206 Pb/ 207 Pb, 208 Pb/ 207 Pb). The analysis of the obtained dataset provided valuable information on the sources and long-range transport processes of atmospheric particulate and associated contaminants reaching the Arctic. In particular, a seasonal pattern was evident for Ba, Cd, Mn, Mo, Pb (p value B0.05), showing a higher input of elements related to anthropogenic emissions in spring compared to summer. Pb isotope ratios clearly showed that the geographic source of the anthropogenic input is subjected to a seasonal shift with an increased contribution of air masses coming from the north Eurasia during spring, and air masses coming from North America during summer. This finding was further corroborated by backtrajectory analysis. Finally, the analysis of the rare earth elements revealed an uniform pattern, without significant differences between the two seasons.
Lead isotopic fingerprinting of 250-years of industrial era pollution in Greenland ice
Anthropocene, 2022
Emissions from mid-latitude industrial activities (e.g., mining, smelting, coal combustion) result in long-range atmospheric transport of lead (Pb) to the Arctic. While previous measurements of elemental concentrations and Pb isotopic ratios in ice and sediments have been used to suggest potential sources of toxic heavy metal pollution in these regions, high resolution Pb isotope records are largely unavailable due to the low Pb concentrations found in Arctic ice. Here we present and interpret a high-resolution, 1759-2008 record of Pb isotopes measured in a central Greenland ice core; the first high-resolution Pb isotope record for Greenland to include the First Industrial Revolution. Records of past industrial activities coupled with Pb isotopic signatures for regional ores and coals suggest Pb pollution prior to the mid-19th century was dominated by emissions from mining and combustion of coals in England, Scotland, and Wales. Rapid 1860s increases in Pb levels and decreases in 206 Pb/ 207 Pb ratios coincided with expansion of coal consumption in Europe and North America. Significant influence of 20th century smelting of Australian Broken Hill Pb ores in Europe resulted in a less radiogenic Pb isotope signature. The phase-out of leaded gasoline and other emissions reductions following passage of airquality legislation in the United States had a pronounced effect on 206 Pb/ 207 Pb ratios, with values falling from 1.187 in 1978 to 1.154 in 1983. Increasing 208 Pb/ 207 Pb ratios through the 1990s and 2000s indicate rising influence of long-range transport from Asia countering declines in European emissions. This 250-year highresolution Pb isotope reconstruction allows attribution of Pb sources to central Greenland with unprecedented detail.
Science of The Total Environment, 2018
To study the long-range transport of atmospheric pollutants from lower latitude industrial areas to the Arctic, we analysed a peat core spanning the last ~700 cal. yr (~AD 1300-2000) from southern Greenland, an area sensitive to atmospheric pollution from North American and Eurasian sources. A previous investigation conducted in the same location recorded atmospheric lead (Pb) pollution after ~1845, with peak values recorded in the 1970s, and concluded that a North American source was most likely. To confirm the origin of the lead, we present new Pb isotope data from Sandhavn, together with a high-resolution record for mercury (Hg) deposition. Results demonstrate that the mercury accumulation rate has steadily increased since the beginning of the 19 th century, with maximum values of 9.3 μg m-2 yr-1 recorded ∼1940. Lead isotopic ratios show two mixing lines: one which represents inputs from local and regional geogenic sources, and another that comprises regional geogenic and pollution sources. Detrending the Pb isotopic ratio record (thereby extracting the effect of the geogenic mixing) has enabled us to reconstruct a detailed chronology of metal pollution. The first sustained decrease in Pb isotope signals is recorded as beginning ~1740-1780 with the lowest values (indicating the highest pollution signature) dated to ~1960-1970. The 206 Pb/ 207 Pb ratio of excess Pb (measuring 1.222, and reflecting pollution-generated Pb), when compared with the Pb isotopic composition of the Sandhavn peat record since the 19 th century and the timing of Pb enrichments, clearly points to the dominance of pollution sources from North America, although it did not prove possible to further differentiate the emissions sources geographically.
Canadian Journal of Fisheries and Aquatic Sciences, 1998
Cu, Hg, Ni, Pb, Se, and Zn concentrations in surface and preindustrial freshwater sediments from 66 lakes in the Norwegian and Russian Arctic were used for studying modern atmospheric deposition of these elements. Statistical analysis showed that, after adjusting for the effects of scavenging factors in sediments (organic matter, Al, and Fe), there were, in general, significantly higher concentrations of Hg and Pb in surface sediments than preindustrial sediments. The differences decreased with increasing latitude and increasing longitude to the east, and in the lakes from arctic islands of Svalbard and along the the arctic coastline of Russia, only Hg concentrations were elevated in surface sediments. We attribute this pattern to modern anthropogenic atmospheric deposition. There were no such differences or regional gradients for the other trace metals. A multivariate analysis of the sediment data showed that Hg and Se were associated with organic matter, whereas Cu, Ni, and Zn were associated with inorganic matter (Al, Fe). There was a shift in Pb association from inorganic matter in the reference sediment to organic matter in the surface sediment, which we interpret as an historic change in importance of sources (from bedrock-derived to atmospheric deposition).
Isotopic composition of lead in moss and soil of the European Arctic
Geochimica et Cosmochimica Acta, 2004
Moss, O and C horizons of podzols, mainly forming complementary sample triplets, as well as filter residues of molten snow from northern Norway, northern Finland and NW Russia have been analyzed by TIMS for their Pb isotopic composition in order to study the impacts of local geogenic/anthropogenic sources and long range atmospheric transport on the Pb balance in the European Arctic. Samples were taken along two N-S transects covering an area of ϳ188.000 km 2 , including both pristine environments in the W and certain regions towards the E severely contaminated by heavy metal emissions originating from large nickel smelters and processing plants in NW Russia. The lead in moss and O horizon samples clearly reflects atmospheric deposition, as it displays overall uniform isotope ratios and is decoupled from the geogenic background, i.e. the underlying mineral soils in the C horizon. Moss and O horizon samples from the eastern N-S transect are isotopically indistinguishable from those taken along the western transect but their Pb concentrations tend to be ϳ2 times higher. This points to considerable contamination originating from the nearby Russian industrial and urban centers. However, isotopic signals of emissions from individual industrial point sources cannot be unambiguously identified because they lack characteristic isotope signatures. Pb derived from gasoline additives is swamped by Pb from other sources and can also be excluded as a major contributor to the environmental Pb in the European Arctic. Overall, the Pb isotopic signatures of moss and O horizon overlap values recorded in atmospheric lead all over central and southern Europe, more than 2000 km south of the study area. This may be taken as indicating continent-wide mixing of Pb derived from similar sources in the atmosphere or as reflecting economic globalization, or both. O horizon samples, which accumulate lead over 20-30 yr, conform to a distinct Pb isotope reference line in 207 Pb/ 206 Pb vs. 208 Pb/ 206 Pb space ("European Standard Pollution," ESP) defined by atmospheric Pb considered to be representative for the technical civilization in Europe. Conversely, the Arctic moss samples with a lifetime of Ͻ3 yr display a deviating linear trend reflecting a recent change of atmospheric input towards significantly more radiogenic Pb derived from Mississippi Valley-type ores in the U.S., fully compatible with signatures found in epiphytic lichens from Canada, but also in Pb from urban waste incinerators in central Europe. Considering the elevated Pb concentrations in moss collected along the eastern N-S transect, this congruence indicates that the Pb in moss of the European Arctic most probably originates from the nearby Russian centers of urbanization and not from transatlantic transport. We therefore suspect imported industrial goods and their subsequent attrition to be a more plausible explanation for the appearance of MVT lead in Europe.
Geochimica et Cosmochimica Acta, 1994
As Patterson and coworkers have shown, most of the lead in the modem ocean and atmosphere is of anthropogenic origin. Reductions in the utilization of leaded gasoline over the past two decades should decrease lead deposition from the atmosphere in remote locations. The search for trends in Pb deposition within a single decade is bedeviled by large-amplitude short-term variability due to the inherent noisiness of the atmosphere/ocean system. We find that, over the course of a year, lead concentrations in the surface waters of the western North Atlantic Ocean are variable (factor of 2), and in the snow deposited in central Greenland, highly variable (order of magnitude). In the western North Atlantic, "'Pb normalization minimizes this problem because 2'oPb and Pb sources are spatially correlated and continental *'OPb emissions are constant. It is clear the Pb in surface waters of the western North Atlantic has decreased by a factor of 4 during the 1980s. "'Pb normalization does not help in the Arctic because stable Pb and "'Pb are not spatially correlated. Because of the order-of-magnitude variability in Greenland snow Pb linked to annual cycles, any discontinuous time series is likely to be affected by the phenomenon of aliasing. Aliasing makes it difficult to determine if there is a trend in Pb deposition in central Greenland during the 1980s; present evidence suggests that the reduction in Pb concentration in snow during the 1980s is less than a factor of two; certainly quite a bit less than observed in the western North Atlantic and less than the factor of >7 reduction in leaded gasoline utilization in the United States during the decade. Although we expect that decadal-scale trends in the 1970s and 1980s are in fact occurring due to the phasing out of leaded gasoline, the reported magnitude of decadal-scale trends should be regarded with some reservation until confirmed by independent samplings.
Stable lead isotope ratios in Alaskan arctic aerosols
Atmospheric Environment. Part A. General Topics
Aerosol samples collected at Barrow, Alaska, during February and March 1990 were found to have uniform stable lead isotope compositions. The mean 2°Spb/2°Tpb ratio was 2.423 + 0.009 and the mean 2°rpb/2°~Pb ratio was 1.161 + 0.014. The latter ratio is essentially the same as that obtained from an earlier study of aerosols at two Canadian stations in the High Arctic and is typical of, but not unique to, Eurasian sources of atmospheric lead. Further discriminating power was available in this study through the inclusion of 2oa pb/2OTpb ratios, which provided additional evidence that the former Soviet Union and eastern Europe are major contributors to atmospheric particulate lead in the Alaskan Arctic, accounting for around twothirds of the particulate lead measured at Barrow. The remaining third of the lead is attributed to west European sources. There was no evidence for a substantial North American component, other than local contamination.