Distribution of mercury species in the Pacific northwest atmosphere

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:214846

Bloom, N S; Prestbo, E B; Geest, E Von der; Kuhn, E ^[1]

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1. Frontier Geosciences, Inc., Seattle, WA (United States)

Gaseous and particulate total Hg and methyl Hg have been monitored in urban air and precipitation on a weekly basis for a year. A limited number of collections from the pristine northwest coast, including gaseous Hg(II) and dimethyl Hg measurements were made later in the program. Total Hg concentrations in urban precipitation ranged from 4-30 ng/L, with highest values in the summer, while those from the pristine site ranged from 1.8-4 ng/L. Methyl Hg concentrations at both the pristine and urban sites were similar, ranging from 0.1-0.4 ng/L, with highest values in the winter. Due to greater precipitation volume at the pristine site, estimated deposition of total Hg was only slightly higher at the urban site (10 {mu}g/m{sup 2}/a) than the pristine site (6 {mu}g/m{sup 2}/a) and the methyl Hg deposition was actually higher at the pristine site (0.6 {mu}g/m{sup 2}/a) than the urban site (0.3 {mu}g/m{sup 2}/a). The precipitation is approximately in Henry`s law equilibrium with gaseous methyl Hg, and an important source of methyl Hg to the atmosphere appears to be evasion and degradation of dimethyl Hg from the ocean.

• OSTI ID: 214846
• Report Number(s): CONF-950801--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AEROSOLS
AIR
ATMOSPHERIC CHEMISTRY
ATMOSPHERIC PRECIPITATIONS
ECOLOGICAL CONCENTRATION
MEASURING METHODS
MERCURY
METHYLMERCURY
PARTICULATES