Atmospheric wet deposition of mercury and other trace elements in Pensacola, Florida
1Department of Oceanography, Florida State University, 117 N. Woodward Ave., Tallahassee, FL 32306-4320, USA
2Center for Environmental Diagnostics and Bioremediation, University of West Florida, 11000 University Parkway, Pensacola, FL 32514, USA
3PetroAlgae, 1901 S. Harbor City Blvd., Suite 300, Melbourne, FL 32901, USA
4Department of Oceanography, Florida State University, 117 N. Woodward Ave., Tallahassee, FL 32306-4320, USA
Abstract. To understand and quantify the impact of local, regional, and distant atmospheric mercury sources to rainfall mercury deposition in the Pensacola, Florida watershed, a program of event-based rainfall sampling was started in late 2004. Modified Aerochem-Metrics wet/dry rainfall samplers were deployed at three sites in the region around the Crist coal-fired power plant and event-based samples were collected continuously for three years. Samples were analyzed for total mercury, volatile elements As, Se, and Sn, and a suite of trace elements including Al, Bi, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ho, Ga, Gd, La, Li, Lu, Mg, Mn, Na, Nb, Nd, Ni, P, Pb, Pr, Rb, Sb, Sc, Si, Sm, Sr, Tb, Th, Ti, Tm, U, V, Y, Yb, and Zn. Nutrients and major ions were also measured on each sample.
Multivariate statistical methods are used to sort these tracers into factors that represent potential source components that contribute to the rainfall chemistry. Hg, As, Se, Sn, Sb, and non sea-salt sulfate were all significantly correlated with one anthropogenic factor. Using various Hg/element ratios, we can estimate that 22–33% of the rainfall mercury in the region results from coal combustion.