Conference proceeding
Atmospheric deposition of organic chemicals in the upper Great Lakes: The role of air-water exchange
12/31/1994
Abstract
Fluxes of PCBs across the air-water interface of lakes Superior and Michigan were determined based on a seasonal source function, matched air-water measurements of PCBs, and wind-driven mass transfer coefficients. In Lake Superior, gas-phase concentrations of PCBs exhibited maxima in May and August, the latter reflecting the terrestrial signal of air emissions. Volatilization dominated in late summer and fall in warmer surface waters while vapor absorption dominated in cool springtime waters. For 1992, net volatilization was estimated to be {approximately} 250 kg/yr. Water column concentrations of PCBs have decreased from {approximately} 2.4 ng/L in 1980 to {approximately} 0.2 ng/L representing a loss of {approximately} 26,500 kg and a first order rate coefficient of {minus}0.20 yr{sup {minus}1}. Mass balance calculations for 1986 suggest net volatilization was about 1,900 kg, compared to sedimentation losses of {approximately} 110 kg. Volatilization of PCBs in lake Superior is significantly greater than sedimentation and outflow losses, and is facilitated by the poor preservation of organic matter and the efficient recycling of PCBs in the benthic region. For Lake Michigan, matched air-water measurements and seasonal air concentrations in 1991--1992 suggest that PCBs volatilize from the lake at a rate of {approximately} 700 kg/yr. These results will be put in context of whole-lake PCB budgets.
Details
- Title: Subtitle
- Atmospheric deposition of organic chemicals in the upper Great Lakes: The role of air-water exchange
- Creators
- S.J EisenreichK HornbuckleJ Jeremiason - Univ. of Minnesota, Navarre, MN (United States). Gray Freshwater Biological InstR PearsonD Swackhamer - Univ. of Minnesota, Minneapolis, MN (United States)C Sweet - ISWS, Champaign, IL (United States)
- Resource Type
- Conference proceeding
- Publisher
- Society of Environmental Toxicology and Chemistry, Pensacola, FL (United States); United States
- Language
- English
- Date published
- 12/31/1994
- Academic Unit
- Occupational and Environmental Health; Civil and Environmental Engineering
- Record Identifier
- 9983997430202771
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