Quantification of Spatial and Temporal Trends in Atmospheric Mercury Deposition across Canada over the Past 30 Years

• DOI: 10.1021/acs.est.1c04034
• Publication Date: 2021-11-18T14:46:06Z
• Authors: Sarah L. Roberts; Jane L. Kirk; Derek C. G. Muir; Johan A. Wiklund; Marlene S. Evans; Amber Gleason; Allison Tam; Paul E. Drevnick; Ashu Dastoor; Andrei Ryjkov; Fan Yang; Xiaowa Wang; Greg Lawson; Martin Pilote; Jonathan Keating; Benjamin D. Barst; Jason M. E. Ahad; Colin A. Cooke
• Keywords: Deposition; Mercury; Longitude

Mercury (Hg) is a pollutant of concern across Canada and transboundary anthropogenic Hg sources presently account for over 95% national deposition. This study applies novel statistical analyses 82 high-resolution dated lake sediment cores collected from 19 regions Canada, including nearby point in remote spanning full west-east geographical range ∼4900 km (south 60°N between 132 64°W) to quantify the recent (1990-2018) spatial temporal trends atmospheric Temporal trend analysis shows significant synchronous decreasing post-1990 fluxes western contrast increasing east, with patterns largely driven by longitude proximity known source(s). Recent sediment-derived agreed well available wet deposition monitoring. Sediment-derived rates also compared modeled values derived model, when sites located (<100 km) were omitted due difficulties comparison at "hot spots". highlights applicability multi-core approaches spatio-temporal changes broad geographic ranges assess effectiveness regional global emission reductions address pollution concerns.