Jean-Pierre Candelone

History of Ancient Copper Smelting Pollution During Roman and Medieval Times Recorded in Greenland Ice

Determination of copper concentrations in Greenland ice dated from seven millennia ago to the present showed values exceeding natural levels, beginning about 2500 years ago. This early large-scale pollution of the atmosphere of the Northern Hemisphere is attributed to emissions from the crude, highly polluting smelting technologies used for copper production during Roman and medieval times, especially in Europe and China. This study opens the way to a quantitative assessment of the history of early metal production, which was instrumental in the development of human cultures during ancient eras.

The lead pollution history of Law Dome, Antarctica, from isotopic measurements on ice cores: 1500 AD to 1989 AD

Abstract Lead isotopic compositions and Pb and Ba concentrations have been measured in ice cores from Law Dome, East Antarctica, covering the past 6500 years. ‘Natural’ background concentrations of Pb (∼0.4 pg/g) and Ba (∼1.3 pg/g) are observed until 1884 AD, after which increased Pb concentrations and lowered 206Pb/207Pb ratios indicate the influence of anthropogenic Pb. The isotopic composition of ‘natural’ Pb varies within the range 206Pb/207Pb=1.20–1.25 and 208Pb/207Pb=2.46–2.50, with an average rock and soil dust Pb contribution of 8–12%. A major pollution event is observed at Law Dome between 1884 and 1908 AD, elevating the Pb concentration four-fold and changing 206Pb/207Pb ratios in the ice to ∼1.12. Based on Pb isotopic systematics and Pb emission statistics, this is attributed to Pb mined at Broken Hill and smelted at Broken Hill and Port Pirie, Australia. Anthropogenic Pb inputs are at their greatest from ∼1900 to ∼1910 and from ∼1960 to ∼1980. During the 20th century, Ba concentrations are consistently higher than ‘natural’ levels and are attributed to increased dust production, suggesting the influence of climate change and/or changes in land coverage with vegetation.

Changes in natural lead, copper, zinc and cadmium concentrations in central Greenland ice from 8250 to 149,100 years ago: their association with climatic changes and resultant variations of dominant source contributions

Abstract We present here the first reliable time series of Pb, Cu, Zn and Cd in Greenland ice for the last climatic cycle. They were obtained by analysing various sections of the 3028.8 m GRIP deep ice core drilled at Summit, central Greenland. Our results show that climatic changes have led to large variations in the concentrations of natural Pb, Cu, Zn and Cd in the high-latitude troposphere of the Northern Hemisphere. Between the interglacial and glacial periods, concentrations have varied by factors of ∼ 320 for Pb, 100 for Cu, 36 for Zn and 13 for Cd. Based on a good correlation between each heavy metal and Al, Pb and Cu are found to have mainly originated from soil and rock dust for both glacial and interglacial periods. On the other hand, continental biogenic emissions were the main source of Cd and to a lesser extent Zn in the Arctic troposphere during the warm Eemian and the Pre-Boreal to Holocene transition, whereas wind-blown dust was the predominant source for these two metals during the cold glacial climatic stages. This characteristic change of relative Cd and Zn contributions from different sources in contrast to that for Pb and Cu is well documented in the ice from the last deglaciation period (15,000 to 8250 yrs ago). After the Younger Dryas event ended, a remarkable increase of Cd Al and Zn Al ratios occurred from 13,000 to 9300 yrs ago, which is consistent with the progressive expansion of vegetation following the retreat of the North American and North Eurasian ice sheets. The subsequent decrease of these ratios to Holocene values can be explained by the stabilization of atmospheric circulation in the northern high-latitude regions, which became similar to that for the Holocene due to further reduction of the Laurentide ice sheet. Finally, the observed variations of the metal/Al ratios suggest changes in the soil and rock dust source regions in parallel with climatic changes which have altered the mean composition of the crustal particles transported to the Arctic.

Lead, Ba and Bi in Antarctic Law Dome ice corresponding to the 1815 AD Tambora eruption: an assessment of emission sources using Pb isotopes

Lead, Ba and Bi concentrations and Pb isotopic compositions have been measured in Antarctic Law Dome (66.8°S, 112.4°E) ice dated from 1814 AD to 1819 AD by thermal ionisation mass spectrometry to investigate the possible deposition of heavy metals from the 1815 AD eruption of Tambora volcano (8.5°S, 117.4°E) in Indonesia. Although volcanic S emissions from Tambora (observed as SO42−) are present in the Antarctic ice core record, there are grounds to question the origin of the Pb and Bi also deposited at Law Dome from late 1817, as the Pb isotope data suggest this Pb originated from Mount Erebus (77.5°S, 167.2°E) on Ross Island, Antarctica. It is shown that at least 97% of any Pb and Bi emitted from Tambora was removed from the atmosphere within the 1.6 year period required to transport aerosols from Indonesia to Antarctica. Consequently, increased Pb and Bi concentrations observed in Law Dome ice about 1818 AD are attributed to either increased heavy metal emissions from Mount Erebus, or increased fluxes of heavy metals to the Antarctic ice sheet resulting from climate and meteorological modifications following the Tambora eruption. Elevated Ba concentrations, observed from mid-1816 to mid-1818, indicate increased atmospheric loading of rock and soil dust also occurred at the time.

Elemental indicators of natural and anthropogenic aerosol inputs to Law Dome, Antarctica

Abstract A selection of elements (Bi, Ca, Cd, Co, Cu, Mn, Na, Sr, U, V, Zn) were measured by high-resolution inductively coupled plasma sector-field mass spectrometry in firn- and ice-core samples from Law Dome, Antarctica, corresponding to the period 4500 BC to AD 1989. Concentrations of rock dust and sea salts were calculated for each sample and then used to determine concentrations of each element originating from crustal and marine aerosol emissions, respectively. Where calculated contributions from crustal and marine aerosol sources failed to account for the total measured concentration of an element, the remainder was apportioned to volcanic and/or anthropogenic sources and defined as an enrichment. On this basis, it was determined that Bi and Cd concentrations in Law Dome ice are overwhelmingly influenced by volcanic emissions (enrichments 150–250x crustal and marine inputs); Co, Cu, Pb and Zn concentrations in Law Dome ice are largely influenced by volcanic emissions (enrichments 16–36x crustal and marine inputs); and Mn, Sr, U and V concentrations in Law Dome ice are minimally influenced by volcanic emissions (enrichments 1.5–4x crustal and marine inputs). During the 20th century, enrichments of Pb and Cu concentrations were observed to be greater than in earlier centuries, consistent with increasing anthropogenic emissions of Pb and Cu in the Southern Hemisphere over that period.

Simultaneous determination of picogram per gram concentrations of Ba, Pb and Pb isotopes in Greenland ice by thermal ionisation mass spectrometry

A technique has been developed to simultaneously measure picogram per gram concentrations of Ba and Pb by isotope dilution mass spectrometry, as well as Pb isotopic ratios in polar ice by thermal ionisation mass spectrometry.

Pb isotope record over one century in snow from Victoria Land, Antarctica.

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The impact of climatic conditions on Pb and Sr isotopic ratios found in Greenland ice, 7–150 ky BP

and Pb+ ions were employed for these determinations. A calibrated mixture of enriched 205Pb and 137Ba was added to the samples providing an accuracy of better than approximately 2% for Pb/Ba element ratio determinations. Interference by molecular ions in the Pb mass spectrum occurred only at 204Pb and 205Pb, but these contributions were negligible in terms of precisions expected on picogram-sized Pb samples. The technique is illustrated with measurements on Greenland firn, using a drill-core section that includes the Laki volcanic eruption of 1783–1784. The data show deviations from the element concentrations indicating volatile metal enrichments, but the Pb isotopic signature of the Laki lava could not be identified.