Modeling the atmospheric transport and deposition of PCDD/F to the Great Lakes.
Atmospheric deposition is a significant loading pathway for polychlorinated dibenzo-p-dioxins and dibenzofurans (dioxin) to the Great Lakes. An innovative approach using NOAA's HYSPLIT atmospheric fate and transport model was developed to estimate the 1996 dioxin contribution to each lake from each of 5,700 point sources and 42,600 area sources in a U.S./Canadian air emissions inventory. These unusually detailed source-receptor modeling results show that deposition to each lake arises from a broad geographical region, with significant contributions from up to 2,000 km away. The source categories contributing most significantly to 1996 dioxin deposition appear to be municipal waste incineration, iron sintering, medical waste incineration, and cement kilns burning hazardous waste. Model-predicted air concentrations and deposition fluxes were consistent with ambient measurement data, within the uncertainties in each, but there may be a moderate tendency toward underestimation using midrange emissions estimates. The most likely reason for this tendency appears to be missing or underestimated emissions sources, but in-situ atmospheric formation of octachlorinated dibenzo-p-dioxin (OCDD) and heptachlorinated dibenzo-p-dioxin (HpCDD) may have also contributed. Despite uncertainties, the findings regarding the relative importance of different sources types and source regions appear to be relatively robust and may be useful in prioritizing pollution prevention efforts.
Cohen
Mark D
MD
NOAA Air Resources Laboratory, Silver Spring, Maryland 20910, USA. mark.cohen@noaa.gov
Draxler
Roland R
RR
Artz
Richard
R
Commoner
Barry
B
Bartlett
Paul
P
Cooney
Paul
P
Couchot
Kim
K
Dickar
Alan
A
Eisl
Holger
H
Hill
Catherine
C
Quigley
James
J
Rosenthal
Joyce E
JE
Niemi
David
D
Ratté
Dominique
D
Deslauriers
Marc
M
Laurin
Rachelle
R
Mathewson-Brake
Larissa
L
McDonald
John
J
D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D001572:Benzofurans / Q000032:analysis*; D016208:Databases, Factual; D000072338:Dibenzofurans, Polychlorinated; D006114:Great Lakes Region; D006256:Hazardous Waste; D008962:Models, Theoretical; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*
D000393:Air Pollutants; D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D006256:Hazardous Waste; D000072317:Polychlorinated Dibenzodioxins; D012989:Soil Pollutants