Concentration and dry deposition of mercury species in arid south central New Mexico (2001-2002)

Environmental Science & Technology
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Abstract

This research was initiated to characterize atmospheric deposition of reactive gaseous mercury (RGM), particulate mercury (HgP; <2.5 μm), and gaseous elemental mercury (Hg0) in the arid lands of south central New Mexico. Two methods were field-tested to estimate dry deposition of three mercury species. A manual speciation sampling train consisting of a KCl-coated denuder, 2.5 μm quartz fiber filters, and gold-coated quartz traps and an ion-exchange membrane (as a passive surrogate surface) were deployed concurrently over 24-h intervals for an entire year. The mean 24-h atmospheric concentration for RGM was 6.8 pg m-3 with an estimated deposition of 0.10 ng m-2h-1. The estimated deposition of mercury to the passive surrogate surface was much greater (4.0 ng m-2h-1) but demonstrated a diurnal pattern with elevated deposition from late afternoon to late evening (1400−2200; 8.0 ng m-2h-1) and lowest deposition during the night just prior to sunrise (2200−0600; 1.7 ng m-2h-1). The mean 24-h atmospheric concentrations for HgP and Hg0 were 1.52 pg m-3 and 1.59 ng m-3, respectively. Diurnal patterns were observed for RGM with atmospheric levels lowest during the night prior to sunrise (3.8 pg m-3) and greater during the afternoon and early evening (8.9 pg m-3). Discernible diurnal patterns were not observed for either HgP or Hg0. The total dry deposition of Hg was 5.9 μg m-2 year-1 with the contribution from the three species as follows:  RGM (0.88 μg m-2 year-1), HgP (0.025 μg m-2 year-1), and Hg0 (5.0 μg m-2 year-1). The annual wet deposition for total mercury throughout the same collection duration was 4.2 μg m-2 year-1, resulting in an estimated total deposition of 10.1 μg m-2 year-1 for Hg. On one sampling date, enhanced HgP (12 pg m-3) was observed due to emissions from a wildfire approximately 250 km to the east.

Publication type Article
Publication Subtype Journal Article
Title Concentration and dry deposition of mercury species in arid south central New Mexico (2001-2002)
Series title Environmental Science & Technology
DOI 10.1021/es0609957
Volume 40
Issue 24
Year Published 2006
Language English
Publisher American Chemical Society
Description 6 p.
First page 7535
Last page 7540
Online Only (Y/N) N
Additional Online Files (Y/N) N
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