1.3
CONSULTATION ON THE HEALTH EFFECTS OF MERCURY, FEBRUARY 27, 2002
conference findings and coming up with a Consensus
1.3.1
Background
1.2
Statement.  The major conclusions in the Consensus
1.3
T
Statement were developed and presented at the conference,
he IJC chose the issue of mercury in the Great Lakes
seeking and receiving input from speakers and participants.
basin as one of its priorities for the 2001-2003
Following the conference, the Consensus Statement was
priorities cycle and the SAB’s Workgroup on
reviewed by U.S. EPA Region 5 scientists involved in mercury
Ecosystem Health prepared the following workplan:
reduction activities as part of the binational toxics strategy.
The following is the consensus statement.
“With advances in toxicology and epidemiology there has
been a reevaluation of the risks associated with exposures
to mercury.  There are concerns that levels in the Great
1.3.2
Consensus Statement from the International
Lakes remain high enough to cause developmental effects
Joint Commission Workshop
in infants.  Mercury is one of the persistent toxic substances
that has been of interest to the International Joint Commis-
Mercury Sources and Sinks
sion under the Great Lakes Water Quality Agreement for a
long time and there is a need, in concert with other parts of
There are numerous anthropogenic sources of mercury to
the organization, to provide the IJC with advice on the
the Great Lakes area environment from local, regional and
current situation.”
global sources (U.S. EPA 1997a).  Anthropogenic sources
increase mercury levels above those resulting from natural
Based on this workplan, the Workgroup on Ecosystem
sources.  Once entering the environment, mercury will cycle
Health undertook a Consultation on the Health Effects of
repeatedly within the biosphere, between earth, air, and
Mercury, at the February 27, 2002 meeting of the
water.  In sediments, it can be converted to methylmercury
Workgroup on Ecosystem Health.  Facts concerning
and biomagnify up the food chain to toxic levels (U.S. EPA
cerebral palsy causation and association with methylmer-
1997a; NRC 2000).  Mercury is of no biological value.
cury poisonings in Minamata and Iraq were discussed as
were other neurological impacts caused by mercury
More detailed evaluations of source inputs and mercury
exposure (NRC 2000; ATSDR 1999).   The participants
speciation, particularly from air sources, will help to better
discussed the various limitations of the approach that had
understand mercury contributions and more effectively
been used by Health Canada under the headings of data
target mercury reduction activities.  Nevertheless, there are
issues (e.g. repeated hospitalization of cases), statistical
powerful techniques based upon a combination of model-
issues and issues concerning alternative etiological factors.
ing and monitoring that can be used to estimate mercury
This consultation concluded with a consensus that more
source contribution to aquatic receptors (Cohen 2001).
research was needed in order to draw any firm conclusions
between a possible relationship of cerebral palsy cases in
Canadian Areas of Concern and exposure to mercury.
Using these techniques, coal combustion appears to be the
largest, unregulated source of mercury air deposition to the
Great Lakes area (Cohen 2001).  Approximately 20 percent
To obtain the most recent information on mercury toxicity,
of mercury loadings to the Great Lakes region are from
the SAB then organized a conference on mercury pollution
global sources outside the United States and Canada,
and human health in the Great Lakes basin, held in
although more information is needed on global mercury
Windsor, Ontario, February 26-27, 2003.  Presenters at the
emissions to reduce uncertainty in loading estimates
conference included leading mercury experts in the world.
(Dastoor 2003; Cohen 2001).  Therefore, international
The conference was designed to address multimedia
cooperation, as in the successful control and phase-out of
sources and sinks, exposures of critical subpopulations,
harmful chloroflurocarbons, will be required to protect
effects, and remedial options and was undertaken in
water resources in the Great Lakes area.
collaboration with the IAQAB and the Health Professionals
Task Force, using an ecosystem approach.
Past practices and former industrial sites, such as mercury
cell chlor-alkali plants, may also contribute mercury
A group of seven health scientists, two on the SAB and five
contamination to the Great Lakes watershed, but these
outside the SAB, were charged with listening to the
17