Stable Lead Isotope Analyses Research Articles

Linking cases of illegal shootings of the endangered California condor using stable lead isotope analysis

Lead poisoning is preventing the recovery of the critically endangered California condor (Gymnogyps californianus) and lead isotope analyses have demonstrated that ingestion of spent lead ammunition is the principal source of lead poisoning in condors. Over an 8 month period in 2009, three lead-poisoned condors were independently presented with birdshot embedded in their tissues, evidencing they had been shot. No information connecting these illegal shooting events existed and the timing of the shooting(s) was unknown. Using lead concentration and stable lead isotope analyses of feathers, blood, and recovered birdshot, we observed that: i) lead isotope ratios of embedded shot from all three birds were measurably indistinguishable from each other, suggesting a common source; ii) lead exposure histories re-constructed from feather analysis suggested that the shooting(s) occurred within the same timeframe; and iii) two of the three condors were lead poisoned from a lead source isotopically indistinguishable from the embedded birdshot, implicating ingestion of this type of birdshot as the source of poisoning. One of the condors was subsequently lead poisoned the following year from ingestion of a lead buckshot (blood lead 556µg/dL), illustrating that ingested shot possess a substantially greater lead poisoning risk compared to embedded shot retained in tissue (blood lead ~20µg/dL). To our knowledge, this is the first study to use lead isotopes as a tool to retrospectively link wildlife shooting events.

Stable lead (Pb) isotopes and concentrations – A useful independent dating tool for Baltic Sea sediments

The prehistory of the Baltic Sea has for a long time suffered from imprecise dating, due to the large uncertainties associated with bulk radiocarbon dating of Baltic Sea sediments. To constrain the timing of environmental changes in the Baltic Sea it is critical to apply new dating approaches. This study identifies lead pollution isochrones in Baltic Sea sediments, which have previously been recorded in lake sediment and peat deposits in northern Europe and ice cores from Greenland. These isochrones have formed through the deposition of atmospheric lead associated with historic lead production and silver mining in Europe, and more recently with the increased industrial emissions that peaked in the 1970’s. Lead concentration and stable lead isotope analyses (206Pb/207Pb ratios) reveal three distinct lead pollution horizons in the Baltic Sea, i.e. a Roman peak at 1 AD, a Medieval peak at 1200 AD and a peak in the 1970s. The new data will improve the chronological accuracy and precision of paleoenvironmental studies in the Baltic Sea, and for the first time, allow synchronization of Baltic Sea geological records within the basin and across Europe and the North Atlantic region (including Greenland).

Contaminated lead environments of man: reviewing the lead isotopic evidence in sediments, peat, and soils for the temporal and spatial patterns of atmospheric lead pollution in Sweden

Clair Patterson and colleagues demonstrated already four decades ago that the lead cycle was greatly altered on a global scale by humans. Moreover, this change occurred long before the implementation of monitoring programs designed to study lead and other trace metals. Patterson and colleagues also developed stable lead isotope analyses as a tool to differentiate between natural and pollution-derived lead. Since then, stable isotope analyses of sediment, peat, herbaria collections, soils, and forest plants have given us new insights into lead biogeochemical cycling in space and time. Three important conclusions from our studies of lead in the Swedish environment conducted over the past 15years, which are well supported by extensive results from elsewhere in Europe and in North America, are: (1) lead deposition rates at sites removed from major point sources during the twentieth century were about 1,000 times higher than natural background deposition rates a few thousand years ago (~10mg Pb m(-2) year(-1) vs. 0.01mg Pb m(-2) year(-1)), and even today (~1mg Pb m(-2) year(-1)) are still almost 100 times greater than natural rates. This increase from natural background to maximum fluxes is similar to estimated changes in body burdens of lead from ancient times to the twentieth century. (2) Stable lead isotopes ((206)Pb/(207)Pb ratios shown in this paper) are an effective tool to distinguish anthropogenic lead from the natural lead present in sediments, peat, and soils for both the majority of sites receiving diffuse inputs from long range and regional sources and for sites in close proximity to point sources. In sediments >3,500years and in the parent soil material of the C-horizon, (206)Pb/(207)Pb ratios are higher, 1.3 to >2.0, whereas pollution sources and surface soils and peat have lower ratios that have been in the range 1.14-1.18. (3) Using stable lead isotopes, we have estimated that in southern Sweden the cumulative anthropogenic burden of atmospherically deposited lead is ~2-5g Pb m(-2) and ~1g Pb m(-2) in the "pristine" north. Half of this cumulative total was deposited before industrialization. (4) In the vicinity of the Rönnskär smelter in northern Sweden, a major point source during the twentieth century, there is an isotopic pattern that deviates from the general trends elsewhere, reflecting the particular history of ore usage at Rönnskär, which further demonstrates the chronological record of lead loading recorded in peat and in soil mor horizons.

A problem with her lead weight

An autistic patient living in a residential home presented with symptoms of weight loss and abdominal pain. On investigation, she was found to have lead poisoning from an unusual source. Her treatment proved difficult due to failure to cooperate, and a 'best-case' protocol was devised. The positive identification of a source of exposure can be difficult in a single case of exposure, but this was eventually achieved by means of stable lead isotope analysis following painstaking detective work.

Determining the History and Sources of Contaminants in Sediments in the Tamar Estuary, Tasmania, Using 210Pb Dating and Stable Pb Isotope Analyses

Environmental Context.Dating estuary sediments provides insights into the materials entering the estuary and can pinpoint when the contamination occurred. Heavy metal contamination is a known health risk but attributing it to a source can be contentious. For a sample sourced downstream of a city and a mining region, lead-210 dating and stable lead isotope analyses uncovered the sources of lead inputs. These methods quantified the extent that upstream mining activities and, for the first time, the extent that non-mining inputs (vehicles, industry) contributed to the estuary’s pollution. Abstract.210Pb dating and heavy metal analyses (Cd, Cu, Pb, Zn) have been combined to establish an historical profile of pollutant levels in sediments in the Tamar Estuary (Tasmania, Australia) over the past century. Heavy metal profiles through the core show a strong correlation with mining activities and industrialization during the past century, reflecting catchment disturbance in one of Australia’s earliest settled areas. A source apportionment of Pb in the sediment core using stable Pb isotope ratios (204Pb, 206Pb, 207Pb, 208Pb) shows that mine pollution has been contributing 10–25 mg kg–1 to Tamar Estuary sediments since the start of mining in the early 1890s, whilst non-mining inputs were not significant until post-1930 and became increasingly significant post-World War II. Since the 1950s–1960s, non-mining anthropogenic Pb inputs have become as significant as Pb from mining activities, although there does appear to be a decline in non-mining inputs during the past 20 years, which is consistent with findings elsewhere where reductions in atmospheric Pb levels have been observed and are attributed to the phasing-out of leaded gasoline. The source apportionment does, however, suggest that Pb from mine pollution at Storys and Aberfoyle Creeks continues to impact upon upper Tamar Estuary sediment quality.

Lead isotope analysis of marine carbonates and seawater by multiple collector ICP-MS

A consistent method for stable lead isotope analysis of marine carbonates and seawater is presented, utilizing multiple collector ICP-MS (MC-ICP-MS). This study presents new observations of the large (0.7% amu −1), time-dependent mass bias determined by thallium normalization, including preferential light ion transmission induced by the acceleration potential and plasma interface ( β=−1.3 to 0.9). These experiments show equivalent results for three empirical correction laws, and the previously proposed β Pb/ β Tl correction does not improve isotope ratio accuracy under these conditions. External normalization to SRM-981 following the thallium correction provides one simple alternative, and a rationale is provided based on secondary bias effects. With current intensities less than 1.5×10 −12 A, external isotope ratio precision better than 250 ppm for SRM-981 207Pb/ 206Pb and 208Pb/ 206Pb ratios is observed (2 σ). From reconstructed lead isotopic variability in the North Atlantic, this instrumental precision results in a signal-to-noise ratio greater than 100. Matrix effects are significant with concomitant calcium in SRM-981 (−280 ppm at 257 μM [Ca]). With the appropriate corrections and minimal concomitants, MC-ICP-MS can reliably determine 207Pb/ 206Pb and 208Pb/ 206Pb ratios of marine carbonates (30 mg) and seawater (160–200 g).

Stable Lead Isotope Analysis of Rio Grande Glaze Paints and Ores Using ICP-MS: A Comparison of Acid Dissolution and Laser Ablation Techniques

High resolution inductively-coupled plasma mass spectrometry (ICP-MS) analyses of stable lead isotopes in Rio Grande glaze paints and New Mexico lead ores (galena) are compared using both acid dissolution and laser ablation techniques. These comparisons demonstrate that acid dissolution is preferable when more accurate measurements are required. In particular, acid dissolution with aqueous induction provided a better match between the archaeological glaze paints and their potential ore sources. However, these comparative studies also show that laser ablation may be an acceptable alternative for examining archaeological materials when the emphasis is on rapid, relatively non-destructive analyses of large data sets.

Using the historical atmospheric lead-deposition record as a chronological marker in sediment deposits in Europe

Atmospheric deposition of large-scale lead pollution has occurred for at least 3000 years in Europe. Metal production and smelting were the main sources until the twentieth century when emissions from vehicles using alkyl-leaded petrol became dominant. Analyses of lake-sediment and peat deposits in Sweden and other regions in Europe, as well as ice cores from Greenland, suggest synchronous temporal changes in past pollution deposition. Characteristic features in the atmospheric pollution fallout were caused by: the peak in lead pro duction during the Roman period; the marked Mediaeval increase in mining and metal production; the rapidly increasing use of cars and leaded gasoline after the second world war along with increased industrial emissions until around 1970, which was followed by a major improvement due to environmental legislation. For northern Europe at least, these characteristic changes can be used to determine, with reasonable accuracy, at which levels ad 0, ad 1000–1200 and ad 1970 are situated in lake-sediment deposits. To identify these levels, stable lead isotope analyses (206Pb/207Pb ratios) have proven to be very useful besides concentration determinations. Particularly useful are the isotope analyses in areas, such as Sweden, where the differences in 206Pb/207Pb ratios are large between the natural catchment lead and the pollution lead.

Stable Lead Isotope Studies of Black Sea Anatolian Ore Sources and Related Bronze Age and Phrygian Artefacts from Nearby Archaeological Sites. Appendix: New Central Taurus Ore Data

The accumulated published database of stable lead isotope analyses of ore and slag specimens taken from Anatolian mining sites that parallel the Black Sea coast has been augmented with 22 additional analyses of such specimens carried out at the National Institute of Standards and Technology. Multivariate statistical analysis has been used to divide this composite database into five separate ore source groups. Evidence that most of these ore sources were exploited for the production of metal artefacts during the Bronze Age and Phrygian Period has been obtained by statistically comparing to them the isotope ratios of 184 analysed artefacts from nine archaeological sites situated within a few hundred kilometres of these mining sites. Also, Appendix B contains 36 new isotope analyses of ore specimens from Central Taurus mining sites that are compatible with and augment the four Central Taurus Ore Source Groups defined in Yener et al. (1991).

Isotopic Tracing of Prehistoric Rio Grande Glaze-Paint Production and Trade

Stable lead isotope analyses, using high resolution inductively-coupled plasma mass spectrometry (ICP-MS), accurately traced the origin of lead ores used in the production of ceramic glaze-paints by prehistoric Pueblo potters in the American Southwest. The analyses show that, despite the availability of other local sources, most potters in north-central New Mexico during the fifteenth century obtained lead from the Cerrillos Hills. These results suggest that certain strategically-located communities may have controlled the distribution of lead within the region. Thus, lead isotope analysis proved an effective technique for examining prehistoric patterns of resource utilisation, production, and exchange.

Stable Lead Isotopes in Teeth as Indicators of Past Domicile—A Potential New Tool in Forensic Science?

A pilot study using stable lead isotope analyses has shown that permanent and deciduous teeth from Eastern and Southern European subjects have completely different lead isotopic compositions to those of Australian subjects. There are statistically significant differences between groups of teeth from subjects from the former Soviet Union (CIS), the former Yugoslavia, United Kingdom, and Lebanon. The isotopic analyses confirm the stability of lead in enamel but suggest that there is exchange of European lead with Australian lead in dentine amounting to about 1% per year. The isotopic differences in, and exchange of, European lead and Australian lead offer an exciting and powerful tool for forensic identification.

Stable Isotope and Concentration Records of Atmospheric Lead Pollution in Peat and Lake Sediments in Sweden

We compare lead concentration and stable lead isotope analyses from three peat bog and three lake sediment records in Sweden. Radiocarbon dated stratigraphies give evidence that trends in the concentration of Pb in the peat and sediment cores are very similar, and follow the general outline of historical global Pb production over several thousand years. Due to the large difference in the 206Pb/207Pb ratio between Sweden, about 1.5, and continental Europe (excluding Fennoscandia), ≤1.2, it is possible to distinguish external sources of Pb to Sweden. In the lake sediments, profiles of 206Pb/207Pb ratio mirror the Pb concentration until 1000 AD; increasing concentration is accompanied by decreasing ratios. After 1000 AD the ratio varies little at about 1.2 in sediments, because of the near total dominance of pollutant Pb. There is a further decline in the Pb ratio to about 1.14 in this century as a result of the addition of alkyl-Pb in petrol. The Pb concentration profiles in the peat match the lakes, but the isotope profiles do not. During the fen-to-bog transition there is a rapid decline in the 206Pb/207Pb ratio from >1.3 to about 1.2, and the ratio continues to decline to the present. We hypothesise that this is because externally-derived Pb from long-range transport of soil dust and atmospheric pollution has always been more important in the ombrotrophic peat than in lakes, which have a greater influx of catchment-derived Pb.

A Technical Examination of the Chinese Buddhist Bronzes in the Freer Gallery of Art, Part B: Stable Lead Isotope Analysis

ABSTRACTStable lead isotope ratios were determined on sixty-four samples taken from sixty of the Buddhist bronze images which were examined and chemically analyzed by Jett and Douglas [preceding paper]. The data were grouped using multivariate techniques and were compared with an accumulated data base of lead isotope measurements on more than 700 ancient Chinese artifacts and more than 200 Chinese and Korean ores. One group of ten images which were all datable to a period of less than one century, Eastern Wei through Sui dynasties, form a nearly unique isotopic group which coincides only with an unusual group of Lengshuichong bronze drums. A second large group of thirty-two isotopically matching images contains almost all, fifteen out of sixteen, of the images attributed to the Northern Wei dynasty. The remaining members of this group are of later date, extending into the Tang dynasty, or are animal figures attributed more generally to the Six Dynasties. This group partially overlaps somewhat the isotope fields of some Western and Eastern Han mirrors and some of the Sackler ritual bronze vessels of the Shang and Zhou dynasties, but appears to have been derived from a different ore source from them. The remaining specimens break up into some very tentatively defined small groups of two to four specimens each and a small residue of four unique, unmatched specimens.