title: Patterns of mercury deposition and concentration in northeastern North America (1996-2002).
abstract: Data from 13 National Atmospheric Deposition Program Mercury Monitor Network (NADP/ MDN) monitoring stations (1996-2002) and the Underhill (VT) event-based monitoring site (1993-2002) were evaluated for spatial and temporal trends. More precipitation and mercury deposition occurred in the southern and coastal MDN sites, except for the Underhill site, which received more mercury deposition than surrounding sites. Precipitation patterns varied. Regionally, higher concentrations of mercury were recorded during the late spring and summer months. Several sub-regional clusters of MDN sites were evident, based on mercury deposition patterns. In general, more mercury was deposited during the summer months. "Enhanced" weekly deposition (> 250 ng/m2) and distinct seasonal deposition patterns were evident at all MDN sites. Regionally, high depositional periods contributed significantly to annual loads (< 20%- approximately 60%). Southern and coastal sites measured more frequent periods of high deposition than inland sites. Spring and summer "enhanced" deposition may be important contributing factors to mercury bioaccumulation during the growing season. Recent regional reductions of mercury emissions were not reflected in the regional mercury concentration or deposition data. Few sites showed linear relations between the concentration of mercury in precipitation and acid rain co-contaminants (sulfates and nitrates).
authors.affiliation: US EPA, 11 Technology Drive, N. Chelmsford, Massachusetts 01863, USA. vanarsdale.alan@epa.gov
authors.forename: Alan
authors.initials: A
authors.lastname: Vanarsdale
authors.forename: Jeri
authors.initials: J
authors.lastname: Weiss
authors.forename: Gerald
authors.initials: G
authors.lastname: Keeler
authors.forename: Eric
authors.initials: E
authors.lastname: Miller
authors.forename: Gille
authors.initials: G
authors.lastname: Boulet
authors.forename: Raynald
authors.initials: R
authors.lastname: Brulotte
authors.forename: Laurier
authors.initials: L
authors.lastname: Poissant
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere; D004784:Environmental Monitoring; D008628:Mercury / Q000032:analysis*; D009656:North America
chemical_list: D000393:Air Pollutants; D008628:Mercury