Six-year trend (1990--1995) of wet mercury deposition in the Upper Midwest, U.S.A.

Journal Article · Fri Oct 01 04:00:00 EDT 1999 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es9806736· OSTI ID:20014646

Glass, G E; Sorensen, J A

Total wet mercury deposition was monitored weekly at six Upper Midwest, USA, sites for a period of six years, 1990--1995, to assess temporal and spatial patterns and contributions to surface waters. Annual wet mercury deposition averaged 7.4 {micro}g Hg/m{sup 2}{center{underscore}dot}yr and showed significant variations between sites and increased trends averaging 0.60 {micro}g Hg/m{sup 1}{center{underscore}dot}yr [8%/yr] over the period. Warm (rain) season wet mercury deposition was found to average 77% of total annual wet deposition. Warm (rain) and cold (snow) season trends showed increases of 0.31 [5.5%/yr] and 0.29 {micro}g Hg/m{sup 2}{center{underscore}dot}yr [17%/yr], respectively. Average annual precipitation depth showed a nonsignificant increase of 0.25 cm/yr [0.4%/yr] for the period. Differences in precipitation depth, mercury concentrations, and wet mercury deposition among sites were noted. Methylmercury wet deposition, measured in 36 weekly samples, averaged about 0.18 ng/L [1.5% of total mercury] in rain and strongly correlated with total mercury, major ions, and precipitation depth.

• Research Organization: Environmental Protection Agency, Duluth, MN (US)
• OSTI ID: 20014646
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 19 Vol. 33; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
AIR POLLUTION MONITORING
ECOLOGICAL CONCENTRATION
MERCURY
METHYLMERCURY
PRECIPITATION SCAVENGING