Abstract:
Mercury (Hg) researchers have made progress in understanding atmospheric Hg, especially with respect to oxidized Hg (HgII) that
can represent 2 to 20% of Hg in the atmosphere. Knowledge developed over
the past ∼10 years has pointed to existing challenges with current methods
for measuring atmospheric Hg concentrations and the chemical composition
of HgII compounds. Because of these challenges, atmospheric Hg experts
met to discuss limitations of current methods and paths to overcome them
considering ongoing research. Major conclusions included that current
methods to measure gaseous oxidized and particulate-bound Hg have
limitations, and new methods need to be developed to make these
measurements more accurate. Developing analytical methods for measurement of HgII chemistry is challenging. While the ultimate goal is the
development of ultrasensitive methods for online detection of HgII directly
from ambient air, in the meantime, new surfaces are needed on which HgII can be quantitatively collected and from which it can be
reversibly desorbed to determine HgII chemistry. Discussion and identification of current limitations, described here, provide a basis
for paths forward. Since the atmosphere is the means by which Hg is globally distributed, accurately calibrated measurements are
critical to understanding the Hg biogeochemical cycle.
