evasion, Great Lakes, land cover, mercury, volatilization
Civil and Environmental Engineering | Engineering
Rates of surface-air elemental mercury (Hgo) fluxes in the literature were synthesized for the Great Lakes Basin (GLB). For the majority of surfaces, fluxes were net positive (evasion). Digital land-cover data were combined with representative evasion rates and used to estimate annual Hgo evasion for the GLB (7.7 Mg/yr). This value is less than our estimate of total Hg deposition to the area (15.9 Mg/yr), suggesting the GLB is a net sink for atmospheric Hg. The greatest contributors to annual evasion for the basin are agricultural (~55%) and forest (~25%) land cover types, and the open water of the Great Lakes (~15%). Areal evasion rates were similar across most land cover types (range: 7.0 to 21.0 μg/m2-yr), with higher rates associated with urban (12.6 μg/m2-yr) and agricultural (21.0 μg/m2-yr) lands. Uncertainty in these estimates could be partially remedied through a unified methodological approach to estimating Hgo fluxes.
Denkenberger, J. S., Driscoll, C. T., Branfireun, B. A., Eckley, C. S., Cohen, M., & Selvendiran, P. (2012). A synthesis of rates and controls on elemental mercury evasion in the Great Lakes Basin. Environmental Pollution, 161, 291-298. doi: 10.1016/j.envpol.2011.06.007