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 ~700cal.yr (~1300-2000CE) 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 19th century, with maximum values of 9.3µgm(-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 19th 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.
Analyses of high-resolution pollen data, coprophilous fungal spores, microscopic charcoal and sedimentology, combined with radiocarbon dating, allow the assessment of the impact of Sami and Nordic land use in the region surrounding the winter market town of Lycksele in northern Sweden. Such winter markets were established by the Crown during the seventeenth century AD to control the semi-nomadic movements of the Sami who traded here with Finnish settlers and were also taxed and educated. Little is known about Sami and Nordic co-existence beyond these market places, mainly due to a lack of archaeological evidence relating to Sami activity. Vegetation and land-use changes in the region between ~ AD 250 and 1825 reveal no signal for pre-seventeenth century agricultural activity, but the coprophilous fungal spore records suggest the increased regional presence of grazing herbivores (possibly reindeer) between ~ AD 800 and 1100. Sami activity in the parish of Lycksele has been suggested by rich metal finds dated to ~ AD 1000-1350 and they may have been attracted by an abundance of reindeer.
