Estimates of recent Hg pollution in Northeast China using peat profiles from Great Hinggan Mountains

Abstract

Ombrotrophic peatlands are regarded as one of the faithful archives of atmospheric mercury (Hg) deposition, and a large number of studies on Hg accumulation in peatlands have been reported in Europe and North America. Comparatively little information is available about peat chronological records of atmospheric Hg flux in China. We investigated the concentration and historical accumulation rate of Hg (Hg AR) through geochemical analysis of three 210Pb-dated peat cores from Great Hinggan Mountain, Northeast China. Statistical analysis indicated no significant correlations between peat humification proxies and Hg concentration. The average Hg concentration (13.3 ± 1.5 µg kg−1) and Hg AR (7.2 ± 0.9 μg m−2 year−1) in the pre-1830 peat layers were designated as the pre-industrial, background values. The temporal variations of Hg AR show an obvious peak in 1980 ± 10, which correspond to periods of specific social activities where heightened Hg pollution was likely. The major peaking period follows a global trend and the decreasing pattern of Hg AR in the last two decades might be likely due to the increasingly intense global environmental regulation on Hg emission.