Volatilization of Polychlorinated Biphenyls from Green Bay, Lake Michigian

Abstract

The volatilization of polychlorinated biphenyls (PCBs) from Green Bay was estimated as part of the Green Bay Mass Balance Study (U.S. EPA). The strategy employed was to simultaneously collect air and water samples above and below the air-water interface, analyze the atmospheric gas phase and the water column dissolved phase for 85 PCB congeners, and calculate the direction and magnitude of flux for each congener using Henry's law and meterological and hydrological parameters. Sampling covered the period of June through October 1989. Air-water transfer rates were calculated for the 14 individual days spanning the three cruises by using the stagnant two-film model. Calculated total PCB volatilization rates ranged from 13 to 1300 ng/m2·day. The most important factors affecting the magnitude of the flux are wind speed and water concentration. The range of fluxes calculated compares well with other estimates for the Grate Lakes. The results of this study support the hypothesis that volatilization is an important phenomenon controlling the fate of hydrophobic organic chemicals (HOCs) in aquatic systems. © 1993, American Chemical Society. All rights reserved.