1.5
THE INTERNATIONAL AIR QUALITY ADVISORY BOARD MERCURY TASK FORCE / COMMISSION ON
ENVIRONMENTAL COOPERATION WORKSHOP ON ATMOSPHERIC MERCURY: SCIENCE AND POLICY –
RESEARCH TRIANGLE PARK, NORTH CAROLINA, DECEMBER 200
years, changes were observed in their dominant
1.5.1
Introduction
1.4
sources and geographic locations.
1.5
T
he IAQAB and the Mercury Task Force of the Sound
The global inventory work of Pacyna & Pacyna (Figure 2)
Management of Chemicals of the Commission for
suggests no significant change in the estimated 2000
Environmental Cooperation co-sponsored two
tonnes per year total global annual release of mercury from
workshops on mercury over the last several years.  The first,
anthropogenic sources to the atmosphere between 1990
The State of Scientific Knowledge Related to Mercury, held
and 1995.  In the 1995 version, North American and
in Las Vegas, Nevada in October 1998, brought together
European sources showed decreasing emissions while the
scientists from the United States, Canada and Mexico to
Asian contribution has increased by over 25 percent,
explore emissions, ambient air, and deposition information
apparently due largely to increased coal combustion in
for the various forms of mercury as well as related impacts
China.
on human and ecosystem health.  Enhancement of source
and ecosystem measurements of mercury and improve-
While there is a distinct albeit imprecise contribution from
ments to available atmospheric models were recommended,
natural sources, anthropogenic sources will continue to
along with more effective communication between the
account for the most substantial portion of total
scientific community and policy makers in planning and
emissions, and, reduction of mercury emissions from
achieving further reductions in anthropogenic emissions.
anthropogenic sources should continue to be aggres-
To address these needs, prominent scientists and policy
sively pursued.
makers from the United States, Canada and Mexico met in
Research Triangle Park, North Carolina in December 2001 at
Emission inventories, particularly in the breadth and
a second joint workshop, Addressing Atmospheric Mercury:
the quality assurance of data collected, appear to lack
Science and Policy.
scope, rigor and transparency.
Estimates of worldwide mercury emissions as well as those
of the three countries were reviewed, along with continental
1.5.3
Transport and Deposition
monitoring activities, including determination of wet
deposition, concentrations in ambient air, and related
It is apparent that further research is needed to better
estimates of dry deposition.  The use of these data in global,
understand the complex atmospheric kinetics and
continental and regional atmospheric mercury transport
chemistry of mercury, the interaction with other
models was examined.  The need for a rigorous characteriza-
pollutants and species, and the subsequent impact on
tion of natural sources of mercury was emphasized.
transport and deposition processes.
Participants recognized the minor but significant global
A mass balance / whole-ecosystem approach is neces-
anthropogenic contribution to mercury loading in North
sary to track the sources and movement of mercury
America and re-emphasized the need for further routine and
throughout the ecosystem, including its entry into and
specialized studies of sources, ambient air concentrations,
further concentration within the food chain.
and related wet and dry deposition determinations.
In assessing the outcome of the meeting, the IAQAB and the
Mercury Task Force of the Sound Management of Chemicals
1.5.4
Monitoring
of the Commission on Environmental Cooperation made
observations and recommendations in several areas.
Establishment of core monitoring sites, with measure-
ment of all relevant chemical species in all relevant
phases, thorough spatial coverage, further standard-
1.5.2
Sources
ization in sampling and analytical protocols and in the
selection and application of meteorological data and
While significant fluctuations in the global emissions
an enhancement in overall quality assurance and
inventories for mercury were not apparent in recent
control are all necessary activities.  Enhanced and
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