Atmospheric mercury deposition to Lake Michigan during the Lake Michigan Mass Balance Study.
Wet and dry mercury (Hg) deposition were calculated to Lake Michigan using a hybrid receptor modeling framework. The model utilized mercury monitoring data collected during the Lake Michigan Mass Balance Study and the Atmospheric Exchange Over Lakes and Oceans Studytogether with high-resolution over-water meteorological date provided by the National Oceanic and Atmospheric Administration (July, 1994-October, 1995). Atmospheric deposition was determined to be the primary pathway for mercury inputto Lake Michigan, contributing approximately 84% of the estimated 1403 kg total annual input (atmospheric deposition + tributary input). Wet (10.6 microg m(-2)) and dry deposition (9.7 microg m(-2)) contributed almost equally to the annual atmospheric Hg deposition of 20.3 microg m(-2) (1173 kg). Re-emission of dissolved gaseous Hg from the lake was also significant (7.8 microg m(-2)), reducing the net atmospheric deposition to 12.5 microg m(-2) (720 kg). A strong urban influence was observed in the over-water mercury deposition estimates in the southern portion of the lake. The Chicago/Gary urban area was estimated to contribute approximately 20% (127 kg) of the annual atmospheric mercury deposition to Lake Michigan. The magnitude of local anthropogenic mercury sources in the Chicago/Gary urban area suggests that emission reductions could significantly reduce atmospheric mercury deposition into Lake Michigan.
Landis
Matthew S
MS
The University of Michigan Air Quality Laboratory, Ann Arbor 48109, USA. landis.matthew@epa.gov
Keeler
Gerald J
GJ
D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D002641:Chicago; D004784:Environmental Monitoring; D006114:Great Lakes Region; D008628:Mercury / Q000032:analysis*; D008962:Models, Theoretical; D014873:Water Pollutants / Q000032:analysis*
D000393:Air Pollutants; D014873:Water Pollutants; D008628:Mercury