ATMOSPHERIC MERCURY (HG) CONCENTRATIONS AND SOURCES IN NEW YORK STATE: A COMPARISON BETWEEN URBAN AND RURAL AREAS

Continuous speciated mercury concentrations were measured in rural (Huntington Forest in the Adirondacks) and urban (Rochester) areas of New York starting in December 2008. Average gaseous elemental Hg (GEM) concentrations and integrated reactive gaseous Hg (RGM), and particulate Hg (Hg_P) concentrations in the ambient air were measured every 3 hours using the Tekran speciation system. To help locate sources of mercury measured at each site 5-day back-trajectories were calculated for GEM, and 2-day back-trajectories were used for RGM and Hg_P (these varying times were based on the variable atmospheric residence times of the different Hg species). During periods of high concentrations it was found that the air parcels were transported mostly from the south and west to the sampling site. These trajectories passed over eastern Pennsylvania and West Virginia where there are several major Hg sources including large coal-fired power plants, oil-fired power plants, and waste incinerators. A few of the trajectories passed over Rochester, NY where the Russell electric generation station and medical and sludge waste incinerators are located and Toronto where waste incinerators are located. Besides back-trajectories, principle component analysis (PCA) was applied here to identify the type of sources; additionally, conditional probability function (CPF) was used to figure out the local sources which are included in the PCA.