Lead from Carthaginian and Roman Spanish Mines Isotopically Identified in Greenland Ice Dated from 600 B.C. to 300 A.D.

Abstract

The pollution history of the atmosphere of the Northern Hemisphere is recorded in the levels of heavy metal impurities in Greenland ice. The possibility also exists of using natural variations in the abundances of lead isotopes to trace the source of this pollution. Lead isotopes have now been measured in ancient Greenland ice with a lead concentration as low as 0.9 pg/g. The results show a depression in the 206 Pb/ 207 Pb ratio between 600 B.C. and 300 A.D., giving unequivocal evidence of early large-scale atmospheric pollution by this toxic metal. This ratio changes from ∼1.201 in ∼8-kyr-old ice to ∼1.183 about 2 kyr ago. Isotopic systematics point to the mining districts in southwest and southeast Spain as the dominant sources of this lead, giving quantitative evidence of the importance of these mining districts to the Carthaginian and Roman civilizations. Lead with a Rio Tinto-type signature represents ∼70% of the lead found in Greenland ice between ∼150 B.C. and 50 A.D. after correcting for the contribution from rock dust indexed to aluminium concentrations. MethodsSample Preparation. We have measured the isotopic composition and concentration of the lead in 26 sections of a 3029 m long ice core from Summit, Greenland (72°34′ N; 37°37′ W; elevation 3238 m), drilled during 1990-1992 for the † This paper is dedicated to the memory of Professor Clair C. Patterson, geochemist at the California Institute of Technology, whose pioneering work on environmental lead has provided the scientific foundation for this study.

A whole‐basin study of sediment accumulation using stable lead isotopes and flyash particles in an acidified lake, Sweden

“…The ratio of 1.15 recorded in the peat bogs is also comparable to the average value of atmospheric aerosols measured in Sweden in 1988 (Hopper et al 1991) (Fig. 4), as well as to the values for forest mosses in Norway (Rosman et al 1998) and Finland (Keinonen 1992). Furthermore, analyses of 50 samples of the soil mor layer (organic horizon) from 11 sites in Sweden also have an average isotope value of 1.15 (1.150 Ϯ 0.007) (Bindler et al 1999); this ratio should represent a time-integrated value spanning a few to several decades, depending on the turnover rate of organic matter in this organic horizon.…”

(Pre-) historic changes in natural and anthropogenic heavy metals deposition inferred from two contrasting Swiss Alpine lakes

“…This last result strikingly agrees with those of the Greenland ice record (Figs. 4 and 5B), whose isotopic systematics point to the mining districts in south Spain as the dominant Pb sources during the Roman Empire (Rosman et al, 1997). Although the signature of the Spanish ingots (from the Cartagene area) shows consistency with the Pb isotope data from the Greenland aerosols, this source ranges off the main mixing lines of Meidsee (Fig.…”

“…The strong similarity of the Meidsee Pb profiles with those from the Greenland ice core is remarkable (Fig. 4), deciphering i) the early large-scale atmospheric pollution by the Roman civilization, ii) the capacity of Meidsee to provide large-scale atmospheric pollution record, and iii) the Spanish mining region as a potential source for the atmospheric lead deposited at high altitude in the Southern Alps (Rosman et al, 1997). In fact, Hg has been mined for ca 2000 years in the Almadén district (central Spain), where Spanish mines alone have contributed to one third of the total historic production of Hg (Hylander and Meili, 2003).…”

“…In order to compare the two records by taking into account the differences in deposition rate, the concentrations of Pb and Hg have (Rosman et al, 1997), Lake Lucerne macrocharcoal AR (Thevenon and Anselmetti, 2007), and the cultural chronology on the lower part. The local Pb and Hg lithogenic backgrounds relative to UCC values are reported on EFs vertical axes (details in the text).…”

“…Conversely, the isotopic composition of lead (Pb), which is unaffected by natural fluxes variability and by anthropogenic processes (e.g., smelting), consistently traces the changing sources of pollution (Sturges and Barrie, 1987;Veysseyre et al, 2001). Investigation of long-term continental records notably revealed variations in Pb accumulation and isotopic composition linked to metallurgical activities since the antiquity (Rosman et al, 1997;Cortizas et al, 2002) whereas the largest atmospheric Pb emissions occurred during the 1970s due to the extensive use of leaded gasoline (Moor et al, 1996;Weiss et al, 1999). Although automobile lead emissions subsequently decreased thanks to the policy initiatives concerning the reduction of lead in petrol, other industrial (i.e., Pb smelters, steel-metallurgy plants, waste incineration) or secondary sources (i.e., wood and coal burning) produced a global re-increase in airborne Pb pollution (Chiaradia and Cupelin, 2000;Flament et al, 2002).…”