Atmospheric Deposition of PCBs and PAHs to the New York New Jersey Harbor Estuary

Lisa A. Totten, Steven J. Eisenreich, Cari L. Gigliotti, Jordi Dachs, Daryl A. VanRy, Shu Yan, and Michael Aucott abstract The objective of this work is to quantify the atmospheric inputs of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) to the New York/New Jersey Harbor Estuary. Atmospheric deposition was quantified by measuring eighty-six PCBs and thirty-four PAHs in air (gas and aerosol) and precipitation at three sites: Jersey City (Liberty Science Center), Sandy Hook, and New Brunswick. These sites are part of the New Jersey Atmospheric Deposition Network (NJADN), a research and monitoring network operated on a twelve-day sampling frequency since 1997. The measured concentrations in the three media were used to calculate atmospheric deposition fluxes to the estuary via three processes: (1) gas absorption, (2) dryparticle deposition, and (3) wet deposition. Concentrations of PCBs and PAHs were generally highest at Liberty Science Center and lowest at Sandy Hook. For the sum of all PCBs measured (EPCBs), these three modes combined deposit between 21 and 56 |g m-2 yr-1 to the estuary, or about 13 to 41 kg yr-1. Gas absorption is the dominant mode of deposition for most PCBs, due to their relatively high vapor pressures, which cause them to exist primarily in the gas phase in the atmosphere. This input is small compared to the inputs to the estuary from wastewater treatment plants and the upper Hudson River, and also in comparison to the volatilization of PCBs from the water column to the atmosphere. It is two to ten times larger, however, than atmospheric deposition fluxes of PCBs to similar ecosystems, such as the Great Lakes and Chesapeake Bay. For PAHs, the three deposition modes result in loadings of414-1,890 |gm-2yr-1 ofphenan-threne, 79-356 |g m-2 yr-1 for pyrene, and 8-42 |g m-2 yr-1 for benzo[a]pyrene (BaP). Gas absorption is the dominant mode of atmospheric deposition for phenanthrene and pyrene. Gas absorption is negligible for BaP due to its higher molecular weight and lower vapor pressure. As with PCBs, these values are two to ten times higher than fluxes of the same PAHs to the Great Lakes and Chesapeake Bay. This difference suggests that the intense urbanization and industrial activity surrounding the New York/New Jersey Harbor Estuary has a large impact on atmospheric loadings of both PCBs and PAHs to the estuary.

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