TY - JOUR
T1 - Evidence for different reactive Hg sources and chemical compounds at adjacent valley and high elevation locations
AU - Sexauer Gustin, Mae
AU - Pierce, Ashley M.
AU - Huang, Jiaoyan
AU - Miller, Matthieu B.
AU - Holmes, Heather A.
AU - Loria-Salazar, S. Marcela
PY - 2016/11/15
Y1 - 2016/11/15
N2 - The spatial distribution of chemical compounds and concentration of reactive mercury (RM), defined as the sum of gaseous oxidized mercury (GOM) and <3 μm particulate bound mercury (PBM), are poorly characterized. The objective of this study was to understand the chemistry, concentration, and spatial and temporal distribution of GOM at adjacent locations (12 km apart) with a difference in elevation of ∼1000 m. Atmospheric GOM measurements were made with passive and active samplers using membranes, and at one location, a Tekran mercury measurement system was used. The chemistry of GOM varied across time and location. On the basis of data collected, chemistry at the low elevation site adjacent to a highway was primarily influenced by pollutants generated by mobile sources (GOM = nitrogen and sulfur-based compounds), and the high elevation site (GOM = halogen-based compounds) was affected by long-range transport in the free troposphere over the marine boundary layer into Nevada. Data collected at these two locations demonstrate that different GOM compounds exist depending on the oxidants present in the air. Measurements of GOM made by the KCl denuder in the Tekran instrument located at the low elevation site were lower than that measured using membranes by 1.7-13 times. Accurate measurements of atmospheric concentrations and chemistry of RM are necessary for proper assessment of environmental impacts, and field measurements are essential for atmospheric models, which in turn influence policy decisions.
AB - The spatial distribution of chemical compounds and concentration of reactive mercury (RM), defined as the sum of gaseous oxidized mercury (GOM) and <3 μm particulate bound mercury (PBM), are poorly characterized. The objective of this study was to understand the chemistry, concentration, and spatial and temporal distribution of GOM at adjacent locations (12 km apart) with a difference in elevation of ∼1000 m. Atmospheric GOM measurements were made with passive and active samplers using membranes, and at one location, a Tekran mercury measurement system was used. The chemistry of GOM varied across time and location. On the basis of data collected, chemistry at the low elevation site adjacent to a highway was primarily influenced by pollutants generated by mobile sources (GOM = nitrogen and sulfur-based compounds), and the high elevation site (GOM = halogen-based compounds) was affected by long-range transport in the free troposphere over the marine boundary layer into Nevada. Data collected at these two locations demonstrate that different GOM compounds exist depending on the oxidants present in the air. Measurements of GOM made by the KCl denuder in the Tekran instrument located at the low elevation site were lower than that measured using membranes by 1.7-13 times. Accurate measurements of atmospheric concentrations and chemistry of RM are necessary for proper assessment of environmental impacts, and field measurements are essential for atmospheric models, which in turn influence policy decisions.
UR - http://www.scopus.com/inward/record.url?scp=85011674026&partnerID=8YFLogxK
U2 - 10.1021/acs.est.6b03339
DO - 10.1021/acs.est.6b03339
M3 - Article
C2 - 27801579
AN - SCOPUS:85011674026
VL - 50
SP - 12225
EP - 12231
JO - Environmental Science and Technology
JF - Environmental Science and Technology
SN - 1520-5851
IS - 22
ER -