Report of the International Air Quality Advisory Board
1.4
INTRODUCTION:  THE INTERNATIONAL JOINT COMMISSION
AND ATMOSPHERIC DEPOSITION
1.4.1
Background
travel time (one day, three day, five day) to the lakes.  These
1.3
and other developments contributed to the inclusion of
T
he International Joint Commission (IJC) has a
Annex 15:  Airborne Toxic Substances in the 1987 Protocol
1.4
longstanding interest in the transport and deposition
to the Great Lakes Water Quality Agreement.
of persistent toxic substances to the Great Lakes
basin via the atmosphere.  Early in the 1980s, working with
TABLE 1
the IJC’s Great Lakes Water Quality Board, in one of the
Critical Pollutants Identified
first estimates of its type, Dr. Steve Eisenreich and Dr.
by the Water Quality Board
William Strachan determined that approximately 90
percent of the loading of PCBs to Lake Superior could be
Total polychlorinated biphenyls (PCBs)
attributed to deposition from the atmosphere.  A similar,
DDT and metabolites
albeit smaller portion of this loading to the other Great
Dieldrin
Lakes was estimated to also arise from this pathway.
Toxaphene
2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD)
In their 1985 report, the Water Quality Board tabled the list
of 11 Critical Pollutants; and for each there was reason to
2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF)
believe or evidence to support the fact that the atmosphere
Mirex
would prove to be a significant pathway.  Following that
Mercury
report, three of the IJC’s advisory boards – Great Lakes
Alkylated lead
Water Quality Board, Great Lakes Science Advisory Board
Benzo(a)pyrene
and the International Air Quality Advisory Board (IAQAB) –
Hexachlorobenzene
began the production of the first binational summary of
emissions estimates for the 11 Critical Pollutants.  The
Source: IJC-GLWQB, 1985
IAQAB also developed a map of the atmospheric region of
influence, indicating such regions on the basis of emission
TABLE 2
Estimates of the Percent of Great Lakes Loadings Attributable to the Atmospheric Deposition Pathway
Pollutant
Lake
Lake
Lake
Lake
Lake
Superior
Michigan
Huron
Erie
Ontario
a
a
a
a
a
DDT
97
98
97
22
31
a
b
d
a
a
a
a
Lead
97  ; 64  ; 69
99
98
46
73
d
j
k
k
k
Mercury
73
> 80
a
b,c
d
a
a
a
a
PCBs
90 ; ~ 95 ; 82
58
78
13
7
c
f
f
f
e
PCDD/F
~ 100
50-100  (PCDD)
86
~ 40
5-35(PCDD)
f
e
e
~ 80
5-35  (PCDF)
< 5 (PCDF)
f
88
a
a
a
a
a
Benzo(a)pyrene
96
86
80
7 9
72
f
f
f
f
f
99
95
96
> 17
40
Hexachlorobezene
k
k
k
k
a
Mirex
~ 5
References and Notes:  (a) Strachan and Eisenreich (1988), percentages of total inputs; (b) Hoff et al., (1996); (c) Net loss of PCBs to
the atmosphere of 1600 kg/year, total non-atmospheric inputs of approximately 70 kg/year; (d) Dolan et al., (1993); (e) Pearson et al.,
(1998); (f) Cohen et al., (1995); (J) Mason and Sullivan (1997); (k) no estimates could be found
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