![]() |
||||
PublicationsOpen-File Reports |
In cooperation with The Town of Ipswich, Massachusetts
By Ann Chalmers, Mark A. Nilles, David P. Krabbenhoft, and Eric Prestbo
U.S. Geological Survey Open-File Report 2005-1368
Available online only
The latest revision of the report is available in PDF format (1,676 KB)
Atmospheric mercury wet-deposition rates were determined by the use of a newly designed wet-deposition sampler at four sites around the Boston, Mass. metropolitan area. The new sampler design was evaluated to determine reliability and capture efficiency. Capture efficiency was lowest during cold and (or) windy winter storms when accumulated ice and (or) snow either overflowed or blew out of the funnel. High capture efficiency (median values of 0.95 and 1.01) occurred with the top-loading type of N-Con sampler, likely reflecting the enhanced collection efficiency of the optical infrared precipitation sensor during light precipitation, and the improved temperature distribution in the top-loading model. Wet-deposition samples collected from January 2002 to August 2004 were analyzed for total mercury (HgT), and a subset of samples from September 2003 to August 2004 were analyzed for methyl mercury (MeHg). MeHg concentrations at all four sites were below the detection level of 0.04 nanograms per liter (ng/L). Precipitation-weighted HgT concentrations during the study were 7.81 to 8.31 ng/L at the more urban sites, and 6.87 ng/L at the regional-reference site. Annual HgT deposition was 8.11 to 9.98 micrograms per square meter per year (g/m2/yr) at urban sites, and 6.56 g/m2/yr at the regional-reference site. Precipitation-weighted HgT concentrations were 2 times higher in the summer than the winter, and the HgT deposition rate was 3 times higher in the spring and (or) summer than in the winter in the Boston metropolitan area.
Acknowledgments
Abstract
Introduction
Study Design
Sampling Methods
Analytical Methods
Quality Assurance
Mercury in Wet-Deposition
Summary
References Cited
Appendix 1. Mercury wet-deposition data from Laconia, N.H.
Appendix 2. Mercury wet-deposition data from Beverly Airport, Beverly, Mass.
Appendix 3. Mercury wet-deposition data from Manchester, N.H.
Appendix 4. Mercury wet-deposition data from Blue Hill, Milton, Mass.
Appendix 5. Sample collection protocol for the N-Con mercury sampler
Document Accessibility: Adobe Systems Incorporated has information about PDFs and the visually impaired. This information provides tools to help make PDF files accessible. These tools convert Adobe PDF documents into HTML or ASCII text, which then can be read by a number of common screen-reading programs that synthesize text as audible speech. In addition, an accessible version of Acrobat Reader 6.0, which contains support for screen readers, is available. These tools and the accessible reader may be obtained free from Adobe at Adobe Access.
For more information concerning the research in this report, contact:
Brian Mrazik, Director
New Hampshire-Vermont Water Science Center
361 Commerce Way
Pembroke, NH 03275
Web site: http://nh.water.usgs.gov
Phone: (603) 226-7807
Email: dc_nh@usgs.gov
AccessibilityFOIAPrivacyPolicies and Notices | |
U.S. Department of the Interior, U.S. Geological Survey
Persistent URL: http://pubs.water.usgs.gov/ofr20051368 Page Contact Information: Publishing Service Center Last modified: Wednesday, December 14 2005, 04:59:47 PM |
![]() ![]() |