Mass balance modeling of PAHs and PCBs in the Chesapeake Bay: Importance of atmospheric deposition and exchange

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:460524

Baker, J; Nelson, E; Nakanishi, K ^[1]

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1. Univ. of Maryland, Solomons, MD (United States)

During the past three years, the authors have measured the concentrations of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyl (PCB) congeners in air, precipitation, surface waters and surficial sediments throughout the mainstem of the Chesapeake Bay. Contaminant concentrations in the water column and surficial sediments show strong decreasing north to south gradients, implying efficient trapping of particle-reactive, volatile contaminants above the estuarine turbidity maximum. Seasonal estimates of water column and surficial sediment contaminant inventories, coupled with estimates of riverine loadings, atmospheric wet and dry aerosol depositional fluxes, and gas exchange rates, allowed them to construct first order mass balances for these semivolatile, particle reactive contaminants. This analysis shows that PAH and PCB water column inventories are extremely small relative to air-water and sediment-water exchange rates, suggesting short residence times and highly variable water column concentrations. The relative importance of the atmosphere as a source of or, in the case of volatile compounds, a sink for contaminants will be addressed with these mass balances.

• OSTI ID: 460524
• Report Number(s): CONF-961149--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
AIR-WATER INTERACTIONS
CARBON SINKS
CHESAPEAKE BAY
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL EFFECTS
MONITORING
POLYCHLORINATED BIPHENYLS
POLYCYCLIC AROMATIC HYDROCARBONS
SEASONAL VARIATIONS
WATER POLLUTION