Effect of recent climate change on Arctic Pb pollution: A comparative study of historical records in lake and peat sediments

Historical changes of anthropogenic Pb pollution were reconstructed based on Pb concentrations and isotope ratios in lake and peat sediment profiles from Ny-Ålesund of Arctic. The calculated excess Pb isotope ratios showed that Pb pollution largely came from west Europe and Russia. The peat profile clearly reflected the historical changes of atmospheric deposition of anthropogenic Pb into Ny-Ålesund, and the result showed that anthropogenic Pb peaked at 1960s–1970s, and thereafter a significant recovery was observed by a rapid increase of 206Pb/207Pb ratios and a remarkable decrease in anthropogenic Pb contents. In contrast to the peat record, the longer lake record showed relatively high anthropogenic Pb contents and a persistent decrease of 206Pb/207Pb ratios within the uppermost samples, suggesting that climate-sensitive processes such as catchment erosion and meltwater runoff might have influenced the recent change of Pb pollution record in the High Arctic lake sediments.

► Historical changes of anthropogenic Pb pollution in Ny-Ålesund were reconstructed.
► Anthropogenic Pb in Ny-Ålesund was largely originated from W. European and Russia.
► Anthropogenic Pb recorded in peat sediments peaked at 1960–1970s and then declined.
► High anthropogenic fluxes were found in recent change of Pb record from lake sediments.
► Climate-sensitive processes might have influenced recent Pb accumulation rate in lakes.