ATMOSPHERIC DEPOSITION OF TOXIC
      SUBSTANCES TO THE GREAT LAKES:
            IADN RESULTS THROUGH 1998
Stephanie Buehler
School of Public and Environmental Affairs and Department of Chemistry,
Indiana University
William Hafner
School of Public and Environmental Affairs and Department of Chemistry,
Indiana University
Ilora Basu
School of Public and Environmental Affairs and Department of Chemistry,
Indiana University
Celine V. Audette
Center for Atmospheric Research Experiments, Meteorological Service of Canada,
Environment Canada
Kenneth A. Brice
Air Quality Research Branch, Meteorological Service of Canada,
Environment Canada
C.H. Chan
Ecosystem Health Division, Ontario Region,
Environment Canada
Frank Froude
Center for Atmospheric Research Experiments, Meteorological Service of Canada,
Environment Canada
Elisabeth Galarneau
Air Quality Research Branch, Meteorological Service of Canada
Environment Canada
Melissa L. Hulting
Great Lakes National Program Office,
U.S. Environmental Protection Agency
Liisa Jantunen
Air Quality Research Branch, Meteorological Service of Canada,
Environment Canada
Melanie Neilson
Ecosystem Health Division, Ontario Region,
Environment Canada
Keith Puckett
Air Quality Research Branch, Meteorological Service of Canada
Environment Canada
Ronald A. Kites
School of Public and Environmental Affairs and Department of Chemistry,
Indiana University

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Atmospheric Deposition of Toxic Substances to the Great Lakes: IADN Results through
1998

Published by
Environment Canada and the United States Environmental Protection Agency
ISBN: 0-662-31219-8
Public Works and Government Services Canada Catalogue Number: En56-156/1998E
US EPA Report Number: 905-R-01-007
Report available in printed form from

Air Quality Research Branch               Great Lakes National Program Office
Environment Canada                      U.S. Environmental Protection Agency
4905 Dufferin Street                      77 West Jackson Boulevard (G17-J)
Toronto ON                              Chicago IL
M3H 5T4                                60604
Canada                                 U.S.A.

and in electronic form at

www.msc.ec.gc.ca/IADN/                 www.epa.gov/glnpo/iadn/

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 ATMOSPHERIC DEPOSITION OF TOXIC SUBSTANCES
TO THE GREAT LAKES:  IADN RESULTS THROUGH 1998

Executive Summary

The Integrated Atmospheric Deposition Network (IADN) was established in 1990 to de-
termine the magnitude and trends of atmospheric loadings of toxic contaminants to the
Great Lakes.  By maintaining a master station on each of the Great Lakes, IADN is able
to monitor the atmospheric deposition  of selected pollutants.  These data have been used
to calculate loadings estimates to the Great Lakes from 1992 to 1996.  IADN incorporates
three atmospheric deposition processes into its loadings estimates: wet deposition, dry
particle deposition, and net gas exchange which combines the processes of gas absorption
(air to water) and volatilization (water to air). This document reports the biennial loadings
to the Great Lakes for 1997 and 1998.

A subset of the substances measured at the IADN master stations are used in the loadings
calculations.   These substances  are  the  pesticides a- and y-hexachlorocyclohexane
(HCH), dieldrin,  />,//-DDE, />,//-DDD, />,//-DDT, trans-nonachlor,  trans- and  cis-
chlordane, a-endosulfan, and  endosulfan sulfate; hexachlorobenzene (HCB) and poly-
chlorinated biphenyl (PCB) congeners 18, 44, 52, and 101, as well as a sum of 56 PCB
congeners and coeluting congener groups expressed as "suite-PCB"; the individual poly-
cyclic  aromatic  hydrocarbons (PAHs) phenanthrene,  pyrene,  benzo[£]fluoranthene,
benzo[&]fluoranthene, indeno[l,2,3-cJ]pyrene  and benzo[a]pyrene as well as a the total
of four of these PAHs expressed  as sum-PAH; and the trace metals lead, arsenic, sele-
nium, and cadmium.

The 1997-1998 loadings presented in this report were calculated in a manner consistent
with the 1995-1996 loadings. The estimates are presented here as flows (kg/yr) to better
understand the amount of the  substances  being deposited to the lakes, and as fluxes
(ng/m2/day) to account for differences in lake areas and to facilitate spatial trend analysis.

Downward fluxes for pesticides in  1997 and  1998 ranged from 0.01  ng/m2/day to 40
ng/m2/day, with in-use pesticides such  as y-HCH accounting for the highest fluxes. Vola-
tilization  fluxes for those pesticides  banned from use were almost 10 times greater than
those for currently used pesticides, reaching  -37 ng/m2/day at  their highest. PCB  and
HCB downward fluxes ranged from 0.02 ng/m2/day to 11 ng/m2/day across the basin.
Volatilization fluxes for these banned  commercial chemicals were on the same order as
those for  banned pesticides.  Suite-PCB volatilization fluxes increased from west to east
across  the  basin.   Downward fluxes for PAHs  ranged from 0.3  ng/m2/day  to 530
ng/m2/day with volatilization fluxes  ranging from  -0.00001 to  -240 ng/m2/day.  Where
water concentration  data are available, volatilization of PAHs  was  almost always less
than  net  inputs. Fluxes for metals ranged  from 13  to 840 ng/m2/day for dry deposition
and from 130 to 5400 ng/m2/day for wet deposition.  Since the metals analyzed by IADN
are nonvolatile, they are not measured  in the gas phase.  The PAHs and  metals measured
by IADN are currently emitted through anthropogenic means into the atmosphere  and

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thus have downward (air to water) fluxes much greater than those of the pesticides and
PCBs that have been banned from use.

Current (1997-1998)  fluxes (ng/m2/day) were compared across time and space to better
understand loadings trends in the Great Lakes.  Pesticide wet deposition fluxes seem to
be generally decreasing over time except for y-HCH at Lakes Huron and Ontario.  Since
y-HCH is still in use, this trend is expected.  Volatilization of dieldrin from Lake Ontario
is the largest pesticide flux observed.  The magnitude of PCB wet deposition fluxes is
similar for Lakes Superior, Erie, and Michigan.  Lake Erie, however, seems unique in
that  all PCBs measured there reached peak fluxes  around  1994  and 1995 and then de-
creased in the following three years. Gas exchange  of PCBs has  been, for the most part,
in  the direction  of net volatilization consistently over time with  only Lake Michigan
showing signs of nearing air-water equilibrium.  Wet and dry deposition of PAHs shows
no real temporal  trend, but spatial analysis indicates  that fluxes have increased from west
to east across the basin.  Gas exchange fluxes for Lakes Superior and Erie for all PAHs
show net absorption over time.  Metal fluxes for Lakes Huron  and Ontario are similar
over the years with dry deposition showing no real  trend and wet deposition decreasing
from 1992-1996  for Cd and Pb, then increasing in 1997 and 1998.

All of the  flows and fluxes mentioned above are based on IADN master  station data.
These stations are remote sites, one on each lake, which measure what are considered to
be Great Lakes background contaminant levels.  However, spatial differences exist across
each lake for many of the compounds we monitor,  particularly near urban  areas, where
atmospheric deposition from cities can be much greater than that from remote sites. In an
attempt to assess the impact of urban areas on lakewide loadings,  and in accordance with
the 1995-1996 loadings report, deposit!onal  data from lADN's  Chicago site were ex-
trapolated onto Lake Michigan loadings.  The impact of Chicago pollution on a small
sub-area of Lake Michigan was then compared to loadings calculated at the  remote mas-
ter station.  Results demonstrate that urban inputs have a minor lakewide effect for most
pesticides.  There does, however, seem to be a large effect on cis- and fram'-chlordane,
drastically changing lakewide volatilization and markedly increasing total mass loadings.
Urban inputs also have a strong effect on the net gas exchange of PCBs.  PAHs, currently
emitted urban pollutants, show consistently large urban effects in all deposition catego-
ries.

In  an attempt to  explore a more tangible means of examining the loadings results, esti-
mates were investigated on a Great Lakes basin-wide basis by summing the total deposi-
tion  flow (kg/yr) of each substance over all five lakes for each year.  These sums give a
good approximation of the larger,  regional atmospheric deposition to the Great Lakes.
Total deposition  for a-HCH showed a decreasing trend, going from 950 kg/yr in 1992 to
-210 kg/yr in 1998. Dieldrin andp,p'-DDE, two  organochlorine pesticides banned from
use,  had negative total  deposition across time,  indicating that the lakes are acting as a
source of these chemicals to the atmosphere.  Sum-PCB total deposition across the basin
also  showed net  volatilization for all years.  Even so,  PCB flows out of the Great Lakes
have decreased dramatically over time, with the largest drop occurring between 1994  and
1995 when total PCB flows went from -3100 kg/yr to -940  kg/yr. PAHs and metals had

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the largest regional deposition.  PAH flows have, for the most part,  remained stable
across time.  While total loads  of metals to the Great Lakes basin have decreased  over
time, the region was still receiving 78000 kg of lead in 1998.
                                        in

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DEPOT ATMOSPHERIQUE DE SUBSTANCES TOXIQUES
 DANS LES GRANDS LACS : RESULTATS DU RMDA JUS-
                                QU'EN 1998

Resume

Cree en  1990,  le Reseau  de  mesure des depots atmospheriques  (RMDA) determine
1'ampleur et les tendances des charges atmospheriques de contaminants toxiques des
Grands Lacs.  Par le maintien d'une station principale  sur chacun des  Grands Lacs, le
RMDA peut surveiller le depot atmospherique de polluants selectionnes. Ces donnees ont
servi a estimer les charges  des Grands Lacs de 1992 a 1996. Le RMDA incorpore trois
processus de depot atmospherique dans ses estimations  de charges : depot humides, de-
pots de particules seches et echange net de gaz qui combine les phenomenes d'absorption
des gaz (de 1'air a 1'eau) et de volatilisation (de 1'eau a 1'air). Ce document rend compte
des charges biennales des Grands Lacs de 1997 et de 1998.

Un sous-ensemble des substances mesurees aux stations principales du RMDA sert au
calcul des charges. II s'agit des  pesticides  a- et y-hexachlorocyclohexane (HCH),  de la
dieldrine,/y?'-DDE, p,p'-DDD,/»,/»'-DDT, de 1'endosulfane trans-nonachlor, trans- eicis-
chlordane, du  a-endosulfane et du sulfate d'endosulfane; des substances organoleptiques
18, 44, 52 et 101 de I'hexachlorobenzene (HCB) et du biphenyle polychlore (BPC), ainsi
que d'une somme de 56  substances organoleptiques et groupes de substances organolep-
tiques coeluantes exprimees sous la forme de «suite-BPC»  des hydrocarbures aromati-
ques polycycliques (HAP);  du phenanthrene, du pyrene, du benzo[£]fluoranthene, du
benzo[6]fluoranthene, de l'indeno[l,2,3-cJ]pyrene et du benzo[a]pyrene, ainsi que du to-
tal de quatre de  ces HAP exprimes sous forme de somme-HAP; et des metaux a 1'etat de
traces que sont le plomb, 1'arsenic, le selenium et le cadmium.

Les charges de 1997-1998 presentees dans  ce rapport ont ete calcul ees d'une fa9on  com-
patible avec les charges  de 1995-1996. Les estimations sont presentees ici sous forme de
debit (kg/an) pour mieux comprendre la  quantite des substances qui se deposent dans les
lacs et sous forme de debit (ng/m2/jour) pour rendre compte des differences existant dans
les zones lacustres et faciliter 1'analyse des tendances spatiales.

Les debits  descendants  des pesticides en  1997 et en  1998 se sont situes entre  0,01
ng/m2/jour et 40 ng/m2/jour, les pesticides en usage comme le y-HCH causant les debits
les plus eleves. Les debits de volatilisation pour les  pesticides dont  1'utilisation est inter-
dite ont ete au moins dix fois plus grands que ceux des pesticides  utilises a 1'heure zc-
tuelle, atteignant -37 ng/m2/jour a leur maximum. Les debits descendants de BPC  et de
HCB se sont  situes entre 0,02 ng/m2/jour et 11 ng/m2/jour dans tout le bassin. Les debits
de volatilisation, pour ces produits chimiques commerciaux interdits, etaient analogues a
ceux des  pesticides interdits. Les debits de volatilisation du Suite-BPC ont augmente de
1'ouest a 1'est dans  tout le bassin. Les  debits descendants des HAP sont alles de 0,3
ng/m2/jour a 530 ng/m2/jour, les debits de volatilisation se situant entre -0,00001 et  -240
ng/m2/jour. Dans les cas ou 1'on disposait des donnees de concentration  de 1'eau, la  vola-
                                       IV

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tilisation des HAP a ete presque toujours infer!eure aux apports nets. Les debits des me-
taux ont oscille  entre 13 et 840 ng/m2/jour pour les  depots sees et entre 130  et 5400
ng/m2/jour pour  les depots humides. Comme les metaux analyses par le RMDA ne sont
pas volatils,  on ne les mesure pas dans la phase gazeuse. Les HAP et les metaux mesures
par le RMDA sont actuellement emis par des moyens  anthropiques dans Tatmosphere et
ont de ce fait  des debits descendants (de 1'air a 1'eau) nettement superieurs a ceux des
pesticides et des  BPC dont 1'utilisation a ete interdite.

On a compare les debit  actuels (1997-1998) (ng/m2/jour)  dans  le temps et 1'espace pour
mieux comprendre les tendances des charges dans les Grands Lacs. Les debits des depots
humides de  pesticides semblent, en general, baisser dans  le temps, sauf pour le y-HCH
aux lacs Huron et Ontario. Comme le y-HCH  est encore utilise, cette tendance est atten-
due. La volatilisation de la dieldrine du lac Ontario est  le debit de pesticide le plus impor-
tant  qu'on ait  observe. L'ampleur des debits de depots humides de BPC  est analogue a
celle des lacs Superieur, Erie et Michigan. Le lac Erie  semble toutefois  unique en ce que
tous les BPC qui y  sont mesures ont atteint leur debit maximal vers 1994 et 1995, debit
qui a baisse au cours des trois annees suivantes. L'echange gazeux de BPC s'est surtout
manifeste par le  renforcement regulier d'une volatilisation nette dans le  temps, seul le lac
Michigan montrant des signes de se rapprocher de 1'equilibre. Les depots humides et sees
de HAP n'indiquent aucune  tendance temporelle reelle, mais une analyse spatiale revel e
que les  debits  se sont accrus d'ouest en est dans tout le bassin.  Les debits d'echanges ga-
zeux du lac Superieur et du lac Erie pour tous les HAP  montrent une absorption nette
dans le temps.  Les debits de metal pour les lacs Huron  et Ontario sont analogues au cours
des ans avec les  depots sees  : aucune tendance  veritable; depot  humide baissant de 1992-
1996 pour le Cd et le Pb, puis augmentant en 1997 et 1998.

Tous les flux et les debits mentionnes reposent sur les  donnees  de la station principale du
RMDA.   II  s'agit de stations reculees, une par lac, qui mesurent ce qu'on considere etre
les niveaux de contaminants de fond des Grands Lacs. II existe toutefois  des differences
spatiales dans  chaque lac pour nombre de composes que nous  surveillons, en particulier
pres des zones urbaines, ou  les  depots atmospheriques des villes peuvent nettement de-
passer ceux  des  stations reculees. Pour tenter d'evaluer 1'effet des zones urbaines sur les
charges panlacustres et suivant le rapport des charges de 1995-1996, les  donnees de depot
de la station de  Chicago du RMDA ont ete extrapolees  aux charges du lac Michigan.
L'effet de la pollution de Chicago sur une petite zone secondaire du lac Michigan a ete
compare aux charges calculees a la station principale  reculee. Les resultats revelent que
les apports urbains exercent un effet panlacustre mineur pour la plupart des pesticides. II
semble bien y  avoir un gros effet, toutefois, sur le cis-  et le trans-chlordane, effet qui mo-
difie enormement la volatilisation panlacustre  et accroit nettement les charges totales de
masse. Les apports urbains produisent aussi un grand  effet sur  1'echange  gazeux net des
BPC. Les HAP,  polluants urbains rejetes a 1'heure actuelle, produisent des effets regulie-
rement importants dans toutes les categories de  depots.

Pour essayer d'explorer un moyen plus tangible d'examiner les  resultats des charges, on a
etudie les estimations sur tout le bassin des Grands Lacs,  en calculant la  somme du flux
total de depots (kg/an) de chaque substance sur les cinq lacs a la fois pour chaque annee.

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Ces sommes donnent une bonne approximation du depot atmospherique regional, plus
grand,  des Grands Lacs.  Les depots totaux de a-HCH ont accuse une tendance a la
baisse, en passant de 950 kg/an en 1992 a  -210 kg/an en  1998.  La dieldrine et  p,p'-
DDE, deux pesticides organochlores dont l'utilisation est interdite, ont eu des depots to-
taux negatifs dans le temps, ce qui signale que les lacs servent de source de ces produits
chimiques pour 1'atmosphere.  Les depots totaux de  somme-PPC dans tout le bassin ont
aussi enregistre une volatilisation nette pour toutes les annees. N'empeche, les flux de
BPC sortant des Grands Lacs  ont enormement baisse dans le temps, la plus forte baisse
survenant entre 1994 et  1995, periode ou les flux totaux de BPC sont tombes de -3100
kg/an a -940 kg/an.  Les HAP et les metaux ont engendre le plus fort depot regional. Les
flux de HAP sont, en grande partie, restes stables dans le temps. Le total des charges de
metaux du bassin des Grands Lacs a baisse dans le temps, mais la region recevait encore
78000 kg de plomb en 1998.
                                       VI

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 Table of Contents

Executive Summary	i
Resume	iv
1. Introduction	1
2. Methods	1
  2.a. Substances Considered	1
  2.b. Calculations	2
  2.c. 1997-1998 Model Refinements	4
  2.d. Data Sources	6
  2.e. Quality Assurance/Quality Control	7
3. Results and Discussion	9
  3.a. 1997-1998 Master Station Fluxes (ng/m2/day)	9
    S.a.i. Organochlorine Pesticides	10
    3.a.ii. PCBsandHCB	11
    3.a.iii.PAHs and Metals	12
  3.b. 1992-1998 Flows (kg/yr)	13
    3.b.i. Organochlorine Pesticides	13
    3.b.ii. PCBsandHCB	14
    3.b.iii.PAHs and Metals	14
  3.c. Temporal and Spatial Flux Trends (1992-1998)	15
    3.c.i. Organochlorine Pesticides	15
    3.c.ii. PCBsandHCB	16
    S.c.iii. PAHs and Metals	17
  3.d. Urban Impacts	17
4. Regional Deposition	24
5. Conclusions	29
Acknowledgements	31
References	32
Appendix A. Selected Data Used in Calculating IADN Loadings	36
Appendix B. Annual IADN Fluxes (ng/m2/d) for 1997-1998	42
Appendix C. Relative Loadings of IADN Substances, 1997-1998	53
Appendix D. Annual IADN Flows (kg/yr), 1992-1998	64
Appendix E. Annual Fluxes to the Great Lakes, 1992-1998	70
Appendix F. Annual Fugacity Ratios for IADN Substances, 1992-1998	86
                                      vn

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List of Tables

Table 1. HLCs used in IADN calculations of gas exchange	5
Table 2. Mass fluxes (ng/m2/day) of atmospheric deposition at Sleeping Bear Dunes
    (SBD), an IADN master station, and Chicago from 1996-1998	20
Table 3. The effect on lakewide loadings of adding flows from Chicago to master station
    estimates of regional  background (BG) flows from Sleeping Bear Dunes	22
Table 4. Annual total deposition flows (kg/yr) to all of the Great Lakes. Each annual
    regional sum includes data from at least three lakes	25
Table Al. Summary of meteorological data at IADN master stations, 1992-1998	37
Table A2. Lake water concentrations for IADN 1997-1998 loadings calculations	38
Table A3.  IADN concentration data availability from 1992 to 1998 for all master stations
    	39
Table A4. Lake water concentration availability for substances used in loadings
    calculations since 1992	40
Table A5. Lake water concentration availability for additional substances added to
    loadings calculations in 1995	41
Table Bl. Annual atmospheric fluxes to Lake Superior for 1997	43
Table B2. Annual atmospheric fluxes to Lake Superior for 1998	44
Table B3. Annual atmospheric fluxes to Lake Michigan for 1997	45
Table B4. Annual atmospheric fluxes to Lake Michigan for 1998	46
Table B5. Annual atmospheric fluxes to Lake Huron for 1997	47
Table B6. Annual atmospheric fluxes to Lake Huron for 1998	48
Table B7. Annual atmospheric fluxes to Lake Erie for 1997	49
Table B8. Annual atmospheric fluxes to Lake Erie for 1998	50
Table B9. Annual atmospheric fluxes to Lake Ontario for  1997	51
Table BIO. Annual atmospheric fluxes to Lake Ontario for 1998	52
Table Dl. IADN annual  flows (kg/yr) from 1992 to 1998 for Lake Superior	65
Table D2. IADN annual  flows (kg/yr) from 1992 to 1998 for Lake Michigan	66
Table D3. IADN annual  flows (kg/yr) from 1992 to 1998 for Lake Huron	67
Table D4. IADN annual  flows (kg/yr) from 1992 to 1998 for Lake Erie	68
Table D5. IADN annual  flows (kg/yr) from 1992 to 1998 for Lake Ontario	69
Table Fl. Fugacity ratios (absorption over volatilization) for gas exchange loadings over
    the Great Lakes	87
                                      vin

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List of Figures

Figure 1. IADN master and satellite sampling stations	6
Figure 2. 1997 annual suite-PCB volatilization fluxes (ng/m2/day) for each lake	12
Figure 3. Total flows of a- and y-HCH (kg/yr) over all Great Lakes	26
Figure 4. Global technical HCH usage in kilotons per year. This figure is taken from Li,
     1999	27
Figure 5. Total flow (kg/yr) of PCBs over all the Great Lakes from 1992-1998.  1997 and
     1998 data represent suite-PCB while previous years represent total PCBs	28
Figure Cl. Loadings as a proportion of total deposition to Lake Superior for 1997	54
Figure C2. Loadings as a proportion of total deposition to Lake Superior for 1998	55
Figure C3. Loadings as a proportion of total deposition to Lake Michigan for 1997	56
Figure C4. Loadings as a proportion of total deposition to Lake Michigan for 1998	57
Figure C5. Loadings as a proportion of total deposition to Lake Huron for 1997	58
Figure C6. Loadings as a proportion of total deposition to Lake Huron for 1998	59
Figure C7. Loadings as a proportion of total deposition to Lake Erie for 1997	60
Figure C8. Loadings as a proportion of total deposition to Lake Erie for 1998	61
Figure C9. Loadings as a proportion of total deposition to Lake Ontario for 1997	62
Figure CIO. Loadings as a proportion of total deposition to Lake Ontario for 1998	63
Figure El. Annual average wet deposition flux (ng/m2/day) of organochlorine pesticides
     	71
Figure E2. Annual average dry deposition flux (ng/m2/day) of organochlorine pesticides
     	72
Figure E3. Annual average net gas exchange flux (ng/m2/day) of organochlorine
     pesticides	73
Figure E4. Annual average total flux (ng/m2/day) of organochlorine pesticides	74
Figure E5. Annual average wet deposition flux (ng/m2/day) of PCBs	75
Figure E6. Annual average dry deposition flux (ng/m2/day) of PCBs	76
Figure E7. Annual average net gas exchange flux (ng/m/day) of PCBs	77
Figure E8. Annual average total flux (ng/m2/day) of PCBs	78
Figure E9. Annual average wet deposition flux (ng/m2/day) of PAHs	79
Figure E10. Annual average dry deposition flux (ng/m2/day) of PAHs	80
Figure Ell.  Annual average net gas exchange flux (ng/m2/day) of PAHs	81
Figure E12. Annual average total  flux (ng/m2/day) of PAHs	82
Figure E13. Annual average wet deposition flux (ng/m2/day) of metals	83
Figure E14. Annual average dry deposition flux (ng/m2/day) of metals	84
Figure E15. Annual average total  flux (ng/m2/day) of metals	85
                                       IX

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1. Introduction

Over the past few decades, the Great Lakes have been the recipient of many different
toxic organic pollutants from a variety of sources.  As the uses of many of these sub-
stances were banned, concentration levels in biota decreased and then seemed to level
off in the mid-80's.  One explanation for this lack of continued reduction was that the
contaminants were coming from the atmosphere.  In an attempt to better understand
the sources of this contamination, the International Joint Commission (UC) held a
workshop  in  Scarborough, Canada in 1986 and  requested that a paper be  prepared
outlining the concentration and flux data for several contaminants.  The product of
this workshop was a report (Strachan and Eisenreich, 1988) identifying atmospheric
deposition as a significant contributor to contamination levels in the Great Lakes.
This report provided enough justification to  include a  separate Annex (Annex  15)
within the 1987 revision of the Great Lakes Water Quality Agreement of 1978.

Among other things,  Annex  15 called for the determination of atmospheric loadings
of toxic substances to the Great Lakes as well as continuing study of temporal and
spatial trends of these substances,  both to be reported to the IJC on a biennial basis.
Most importantly, the Annex called for the creation of the Integrated Atmospheric
Deposition Network  (IADN) to carry out surveillance and monitoring of the toxic
contaminants. In 1990, the first Implementation Plan (Egar and Adamkus, 1990) was
signed. It laid out the chemicals to  be measured, siting and sampling methods, and the
Quality Assurance/Quality Control program that would  ensure that data was consis-
tent over time and between sampling agencies.

In accordance with Annex 15, IADN has produced biennial  loadings  estimates on
data from 1992 through  1996 (Hoff, 1996; Hillery et  al., 1998;  Galarneau et  al.,
2000).  This report details the 1997 and 1998 loadings to the Great Lakes and follows
closely the methodology and format of the previous reports.  As with the previous
documents, the centerpiece of this report is atmospheric loadings.  Other pathways
besides atmospheric deposition do  exist that may contribute to the total loadings, such
as point sources, tributary input, and  bubble spray production.  Because of this,  the
atmospheric loadings presented here should not be seen to represent the only contri-
butions of toxic contaminants to the Great Lakes.
2. Methods
2.a. Substances Considered

Previous IADN loadings results (Hoff,  1994; Hoff et al., 1996; Hillery et al., 1998)
have   reported   on  20   substances.      These   substances  are  a-  and   y-
hexachlorocyclohexane (HCH),  dieldrin,  />,p'-DDE, /y/-DDD, />,//-DDT,  hexa-
chlorobenzene (HCB),  poly chlorinated  biphenyl (PCB) congeners  18, 44, 52,  and

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101, as well as total PCBs  £PCB);  individual poly cyclic aromatic hydrocarbons
(PAHs) phenanthrene, pyrene, benzo[&]fluoranthene, and benzo[a]pyrene; and  the
trace metals lead, arsenic, selenium, and cadmium.  The  1995-1996 loadings report
(Galarneau et al., 2000) added the species trans-nonachlor, trans- and c/'s-chlordane,
a- and  |3-endosulfan, endosulfan  sulfate,  benzo[&]fluoranthene, and indeno[l,2,3-
cd]pyrene.  The PAHs benzo[a]pyrene, benzo[&]fluoranthene,  benzo[&]fluoranthene,
and indeno[l,2,3-cd]pyrene comprise a list of PAHs suggested for reporting under the
United Nations Economic Commission £>r Europe Long-Range Transboundary  Air
Pollution (UNECE  LRTAP)  Convention's 1998 Aarhus  Protocol on Persistent Cr-
ganic Pollutants (POPs) (UNECE, 1998). These individual PAHs were then summed
to give sum-PAH loading results.

In accordance with all previous loadings calculations, the 1997-1998 results presented
here will report on the same list  of 28  substances described above, with two excep-
tions. First, P-endosulfan will not be reported because no reliable Henry's Law con-
stant could be found, putting previous results for this pesticide into question. Second,
ZPCB will be presented as suite-PCB for 1997 and 1998 results. ZPCB represents a
sum of congeners  determined by each individual analytical laboratory that partici-
pates in the IADN project.  In an attempt to report one consistent sum of PCB conge-
ners across all  agencies,  a suite  of PCBs was developed.  This suite encompasses
those PCB  congeners that contribute an important percentage to the overall total PCB
mass in gas and precipitation phases.  The congeners in the suite are also considered
to be lexicologically important.   The resulting suite-PCB  contains 56 congeners and
congener groups that are  representative of the entire range of PCBs (Neilson, 2000).
While the number of congeners used in suite-PCB is approximately half of what was
used by some agencies in previous ZPCB calculations, these 56 congeners account for
approximately  90%  of the total PCB mass at  each site. Thus, the averages found for
suite-PCB are not largely  different from ZPCB averages.
2.b. Calculations

Detailed descriptions of the loadings calculations can be found  elsewhere  (Hoff,
1994; Hoff et al., 1996; Hillery et al.,  1998). A brief summary will be presented here.
Net atmospheric flows (L, in kg/yr) are based on three processes: wet deposition, dry
deposition, and net gas exchange.  They are represented by the equation:

L=CpRpA+CJavdA+[kol(l-$a)Ca(RT/H)A-kol(l-$w)CwA]             (1)

Wet deposition is the product of the  volume-weighted mean precipitation-phase
concentration, Cp (kg/m3), the rate of precipitation, Rp (m/yr), and the area of the lake,
A (m2).  In a similar manner, dry deposition is the product  of the total atmospheric
concentration of the pollutant, Ca (kg/m3), the fraction of the compound in the particle
phase,  (j)a, the deposition velocity of the particles, Vd (m/yr),  and the area of the lake.
Gas transfer is divided into two components: volatilization and absorption.  The vari-
able, &0/(m/yr), is the overall air-water mass transfer coefficient,,/? (atm m3 K"1 mol"1)

-------
is the ideal gas constant,  T (K) is the temperature at the air-water interface, H (mol
atm"1  m"3) is the Henry's Law constant, and Cw (kg/m3) is the concentration of the
compound in the water. For absorption,  (1 - §a)Ca is the  concentration of the com-
pound in the gas phase. Absorption is the transfer of the compound in the gas phase
from air to water. For volatilization,  (j)w is the fraction of the compound on the parti-
cle  phase in the water, thus making (1 - (f)w)Cw the dissolved concentration  of the
compound of interest.  Volatilization  is then the transfer of the compound from water
to air. Net  gas exchange is the sum of the absorption and volatilization estimates.
Positive net  gas exchange indicates absorption, while negative net gas exchange indi-
cates volatilization.

The gas  exchange calculations are made based on the two-film air-water exchange
model (Schwarzenbach et al., 1993).  Typically, this model uses relationships involv-
ing  the mass transfer coefficients of CO2 and FfcO to determine, respectively, the wa-
ter-side and  air-side mass transfer coefficients for the chemical of interest, which are
then used to determine k0i(Schwarzenbach et al., 1993; Hornbuckle et al.,  1994;  Hoff
et al., 1996). Galarneau et al. (2000)  simplified these mass  transfer calculations in the
1995-1996 loadings report by replacing Schmidt number ratios with diffusivity ratios
and then further leducing diffusivity calculations to simpler terms involving molar
and diffusion volumes and masses. These same simplifications are used in the calcu-
lation of the  results presented here.

The loadings estimates are presented  in this report as annual values  and as both flows
and fluxes.  Fluxes (ng/m2/day) are simply the flows (kg/yr) converted to ng/day and
divided by the appropriate lake area.  These areas are  82,100 km2 for Lake Superior,
57,800 km2  for Lake Michigan, 59,600 km2 for Lake Huron,  25,700 km2 for Lake
Erie,  and 18,960 km2 for Lake Ontario.  Fluxes allow for comparisons between the
lakes  by  removing the variation due  to differing lake  areas.  Flows and fluxes were
calculated seasonally and then summed to give annual  loads and averaged to give an-
nual fluxes.

For the 1997-1998 annual fluxes, errors are presented for each term as a coefficient of
variation (COV).  These COVs were  calculated in accordance with the error propaga-
tion analysis by Hoff (1994).  The major sources of the errors are associated with the
spatial and temporal  variability of the samples as well as  the  large uncertainties in-
volved in the physical parameters used,  such  as the Henry's  Law  constants  (Hoff,
1994; Hillery et al., 1998).  For dry deposition and gas exchange, a COV  of < 267%
indicates that the annual fluxes are significantly different from zero  at the 95% confi-
dence interval (Galarneau et al., 2000). Similarly, for wet  deposition, fluxes are sig-
nificant if the COV is < 165%. Because of a different precipitation phase sampling
schedule  on Lake Huron, wet deposition there is significant if the  COV is < 248%
(Galarneau et al., 2000).

All  results reported here are only estimates.  In fact, the error  inherent  in individual
results, such as gas exchange and volatilization, can be quite large.   As  estimates are
aggregated,  however,  results become more reliable.  For instance, examining the

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loadings over time or in terms of regional deposition imparts more reliability to the
results. Even total deposition is a more reliable way to interpret the results than indi-
vidual deposit!onal components are.  Thus, individual loadings terms should not be
regarded as precise numbers, but should be viewed more as a means to understand the
behavior of the chemicals across time and space in the Great Lakes basin.
2.c. 1997-1998 Model Refinements

A few refinements were made to the loadings model for the 1997-1998 calculations.
The Henry's Law constant (HLC) for a-endosulfan was updated. In order to compare
the  loadings across time, the  1995 and 1996 loadings for a-endosulfan were recalcu-
lated using this new HLC. Previous years loadings did not have to be updated since
a-endosulfan was  only added to the list of  substances considered in 1995.  This
year, p-endosulfan was removed from the  list of  species  because no reliable HLC
could be found.

This discovery  called into question the 1995-1996 results, so  no P-endosulfan load-
ings are presented here. A list of all the HLCs used is given in  Table 1.

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Table 1. HLCs used in IADN calculations of gas exchange
Substance

a-HCH
dieldrin
c/5-chlordane
/ram'-chlordane
trans -nonachlor
p,p'-DDD
p,p'-DDE
p,p'-DDT
y-HCH
a-endosulfan
HCB
PCB 18(tri)
PCB 44 (tetra)
PCB 52 (tetra)
PCB 101 (penta)
phenanthrene
pyrene
benzo[&]fluoranthene
benzo[&]fluoranthene
benzo[a]pyrene
indeno[l,2,3-
ct(]pyrene
Parameters m
and b for
Henry's Law
Constant, H
(Pa»m3/mol),
logwH=m/T+b
m
-3054
-3416
-3416
-3416
-3416
-3416
-3416
-3416
-2694
-1001
-2559
-2611
-2716
-2716
-3416
-2469
-2239
-3416
-3416
-3416
-3416
b
10.1
12.2
12.5
12.7
13.2
11.3
12.6
11.7
8.54
4.26
10.4
10.4
10.5
10.4
12.9
8.89
7.59
10.4
10.7
10.8
6.95
Source

Gotham and Bidleman (1991); Jantunen and
Bidleman (2000)
Cotham and Bidleman (1991)
Iwataetal. (1995)
Iwataetal. (1995)
Iwataetal. (1995)
Suntio et al. (1987); Tateya et al. (1988); as per
Hoffetal. (1996)
Iwataetal. (1995)
Cotham and Bidleman (1991)
Cotham and Bidleman (1991); Jantunen and
Bidleman (2000)
Riceetal. (1997)
Ten Hulscher et al. (1992)
Murphy et al. (1987); Ten Hulscher et al.
(1992)
Murphy et al. (1987); Ten Hulscher et al.
(1992)
Mackay et al. (1992); Ten Hulscher et al.
(1992)
Murphy et al. (1987); Ten Hulscher et al.
(1992)
Bamford et al. (1999)
Bamford et al. (1999)
Ten Hulscher et al. (1992)
Ten Hulscher et al. (1992)
Ten Hulscher et al. (1992)
Ten Hulscher et al. (1992)

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 2.d. Data Sources

IADN collects gas, particle, and precipitation phase samples at each of its master sta-
tions, one on each of the Great Lakes (see Figure 1).  Sampling details can be found
elsewhere (Environment Canada, 1994; Basu, 1996).  Vapor and particle phase sam-
ples were collected every 12 days for 24 hours at a time. At Lakes Erie, Michigan,
and Superior, approximately 815 m3  of air were collected using XAD-2 resin to trap
the gaseous  contaminants.  At Lakes Huron and Ontario, the average volume of air
collected was 350 m3 using  polyurethane foam (PUF) to trap  the gaseous contami-
nants.  Canadian sites used glass fiber filters for particle  phase collection, while U.S.
sites used quartz fiber filters (QFF).  Precipitation-phase samples were collected as
28-day composites at the U.S. sites  and Lake Ontario.  Precipitation samples were
collected as 14-day composites at Lake Huron.
      49  -
     47  -
   0)
  -a  45
      43  -
      41
                              |ADN
                        Master Stations  •
                        Satellite Stations <>
                   L Michigan)    /Sleeping
                              \     \ Bear
                              f     \j Dunes
                       I IT Chi cage
                                        Point
                                ^Egbert  Petre ,/-
                         ndfeend  V    _^n^K
                                    f—~	• ./?
                             Burlim
                                                              Sturgeon
                                                              Point
                            L. Erie
        - 93
 I
89
    -85           -81
Longitude (W)
-77
Figure 1. IADN master and satellite sampling stations
Meteorological data, including wind speed and precipitation measurements necessary
for the loadings calculations, were collected on-site at each master station.  Annual
and seasonal averages were then determined from these measurements to use in the
calculations. Lake water surface temperatures were obtained from the National Oce-
anic Atmospheric Administration's (NOAA) Great  Lakes Environmental Research

-------
Laboratory (GLERL) satellite data (NOAA, 2000).  Annual meteorological data can
be found in Table Al of Appendix A.

Lake water concentrations are crucial to the loadings calculations. However, IADN
does not make these measurements.  In order to perform the calculations, water con-
centration  data for 1997 and 1998 from available sources were used. If more than one
source was available for a given lake for one year, the water concentration data were
pooled by  the method of weighting by inverse variance (Taylor, 1990).  The lake wa-
ter concentrations that were used and their sources are listed in Table A2 of Appendix
A.

This report will explore temporal and spatial trends  in contaminant fluxes and flows
from  1992-1998.   Over  this time, there have been  some  missing  contaminant
concentration data as well as lake water concentration data. These missing data mean
that results cannot be reported for certain substances. For example, without any water
concentration data for endosulfan  sulfate, no volatilization estimates  can be made.
We have constructed data availability charts for air and water concentration data over
the years in Tables A3 through A5 in Appendix A.  These charts serve as a guide to
understanding when unreported fluxes or flows are a  result of missing data.
2.e. Quality Assurance/Quality Control

IADN follows a strong quality assurance program.  The Quality Assurance Program
Plan (QAPP) was documented jointly by Environment Canada, the United States En-
vironmental Protection Agency, and the Ontario Ministry of the Environment and En-
ergy (February 1994). Each agency developed their own Quality Assurance Project
Plan (QAPjP).  In the United States, Don Gatz wrote the QAPjP in 1990 and then re-
vised  it (Gatz, 1993) for the IADN project at Illinois  State Water Survey.  Subse-
quently, it was modified at Indiana University (IU) (Basu, 1994 and 1995). The Ca-
nadian QAPjP was first  developed by TRC  Environmental Corporation in 1993  and
has been updated as needed.  Environment Canada laboratories are accredited by the
Standards Council of Canada (SCC) through the Canadian Association for Environ-
mental Analytical Laboratories (GAEL) to  SCC Guide CAN-P-4D and must meet
ISO Guide 17025 requirements.  Laboratories undergo regular (biennial) performance
tests for organochlorine and PAH parameters and biennial audits of the methods used.

All air  and precipitation chemical data and all  meteorological  data measured by
IADN go through a quality control process via the Research Data Management and
Quality Control  System™ (Sukloff et al., 1995) at the Center for Atmospheric Re-
search Experiments of Environmental Canada.

Recently, a laboratory audit of all IADN participants was carried out by Peter Fowlie
of Cornerstone Science (Fowlie, 2001). Below is a summary of the findings taken di-
rectly from the report:

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    A laboratory audit program was carried out to ensure that the SOPs were being followed
    by the individual laboratories. A comparison of the different analytical approaches used
    by each laboratory was made and findings for each laboratory were presented. The analy-
    tical methods are logical and capable of producing defensible data. A few of the SOPs
    were out of date.  Occasionally, lab practice varies from a current SOP, but variances
    were of a relatively minor nature and do not constitute major errors affecting data quality.
    The different sampling and analysis methods used in the program have the potential to
    cause between laboratory bias in the data.

    The IADN Quality Assurance Program Plan (QAPP) was reviewed by the IADN Steering
    Committee in January 2000 and the updated  Revision 1.1 of the QAPP was issued to all
    Steering Committee members in July 2001.

    A Common Reference Standard for the IADN suite of PCBs, Pesticides and PAHs was
    implemented.  Although these standards do not replace the existing calibration standards
    used in participating laboratories, they  were used as round robin  standards and will be
    used as independent check standards to verify continuing calibrations.

    A split sample interlaboratory round robin was carried out in early 2001 to evaluate equi-
    valence of data for IADN  organics. With the exception of a few particular PAHs and pes-
    ticides, the round robin demonstrated reasonable  agreement for trace organic data.  Preci-
    pitation data is less precise than PUF data which is, in turn, less precise than OFF data.

    For PAHs, IU  [Indiana University] reports data about 30% higher than MSC [Meteorolo-
    gical Services of Canada]  for PUF samples but there was no such bias for OFF or melted
    snow. For PCBs, NLET [National Laboratory for Environmental Testing] reports data
    about 40% higher than IU in melted snow.  IU reported data about 30% higher than MSC
    on PUF. This implies that NLET PCB data is biased quite high compared to MSC. For
    pesticides, IU reports data about 30% higher than MSC in PUF but comparable to NLET
    on the melted  snow. It is  important to note that  these results can only be applied to one
    point in time early in 2001 and should not be applied without caution to the 10 years of
    the IADN program.

    A split sample co-located sampler program was  operated at Point Petre during 2000 and
    2001.  Monthly paired samples showed some disagreement which should be resolved.
    (Fowlie, 2001)

Based on the results of our quality assurance studies to date,  differences among si-
tes/lakes, as  cited in this loadings report, should be viewed in consideration  of the
identified measurement differences  among  agencies  involved in IADN.   We  are
continuing to address this issue to be sure that data are compatible.  Another question
may arise as to the consistency of the procedures as the United  States lab switch from
the Illinois State Water Survey (ISWS) to IU in 1994.  From its inception, Dr. Basu
has been with the project.   A  co-developer of the Standard Operating Procedures at
ISWS, Dr. Basu  followed the  same procedures  at IU and had  any modifications ap-
proved by the EPA.

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3. Results and Discussion

The results presented here will be discussed in two distinct forms: as flows and as
fluxes. Flows are always presented in kg/yr while fluxes are in ng/m2/day. The term
"loadings" is defined in the IADN Second Implementation Plan as the transfer of the
chemical to the ".. .water or watershed in units of mass per square meter per unit time
or...mass per year" (Environment Canada and Great Lakes National Program Office,
1998) and will thus be used  generally throughout this report to represent both flows
and fluxes. "Loadings" should be considered a generic, all encompassing term in this
document, representative of the  atmospheric deposition of pollutants to the Great
Lakes in  any units.

The flows and fluxes, or loadings, will often be referred to as downward.  Downward
flows and fluxes are those that go from the air to the lakes.  Gas absorption, wet
deposition, and dry deposition are all downward loadings, as are positive net gas ex-
change and positive total deposition. An upward loading would thus be the move-
ment of the contaminant from the lake water to the air. This process is referred to as
volatilization. Negative flows and fluxes indicate volatilization.

When chemicals are being volatilized out of the water, the lakes are often referred to
as sources of these chemicals to the atmosphere. This is not to suggest that the lakes
are the original sources of the chemicals to the Great Lakes atmosphere, but merely to
indicate that after years of the  chemicals being deposited to the lakes through the at-
mosphere, tributary inputs, direct dumping, and other means, the  lakes are  now le-
leasing these sub stances into the overlying air.
3.a. 1997-1998 Master Station Fluxes (ng/nf/day)

The main purpose of this report is to calculate the biennial loadings for 1997 and
1998 and add these results to previous years (1992-1996) results in order to explore
spatial  and temporal trends in the flows and fluxes.  However, it is also important to
analyze the current results (1997-1998) to gain a better understanding of how these
chemicals are now behaving in the Great Lakes basin.

The 1997-1998 results will be presented as annual and relative fluxes.  Tables Bl to
BIO in Appendix B give the annual daily fluxes (ng/m2/day) for each substance for
each lake. Each table represents one lake and gives wet and dry deposition fluxes as
well as gas exchange fluxes,  which include gas absorption, volatilization, and net gas
exchange.    Seasonal  fluxes  are   not  reported  here  but can be  found  at
http://www.msc.ec.gc.ca/iadn/results/DEFAULT_e.html and are available upon  E-
quest.  Annual averages from 1992 through 1998 are also available on the website or
by request.

-------
Figures Cl through CIO in Appendix C show the relative loadings for each substance
for each lake in a given year (1997 and 1998).  The sum of the downward inputs,
from air to water, for each substance is normalized to 100%. The individual down-
ward loading components (wet deposition, dry deposition, and gas absorption) are
then expressed  as a positive percentage of this normalized sum.  The volatilization
loading term in the  graphs is expressed as  a negative percentage of the summed
downward loadings.  A substance that has a relative volatilization term greater than -
100% is experiencing a net loss from the water to the air.   Substances that show net
downward and upward relative loadings of the same proportion can be said to be  at
equilibrium between the lake water and the overlying air.
S.a.i. Organochlorine Pesticides

IADN measures both in-use pesticides and those whose uses have been banned (re-
ferred to as "banned pesticides").  Tables Bl through BIO list the two groups.  Indi-
vidual downward fluxes  (from air to water) for banned organochlorine pesticides
range from 0.01 ng/m2/day  to 22 ng/m2/day across the basin, while volatilization
fluxes range from -0.002 to -37 ng/m2/day. The inputs for these substances on Lakes
Superior, Michigan, and Erie are dominated by gas absorption. Over Lake Ontario,
gas absorption dominates the inputs of almost all of the banned pesticides  in 1998,
but in 1997, wet deposition dominates the inputs of pp}-DDT and p,p'-DDD. Wet
deposition mainly  dominates  inputs of DDT-related  compounds at Lake Huron.
However, since pesticides are not measured in the particle phase over this lake, esti-
mates of their dry deposition fluxes cannot be made, thus making it hard to draw any
real conclusions.

a-HCH and c/s-chlordane are near air-water equilibrium in Lakes Huron and Ontario.
However, 1998 relative loadings graphs for  these lakes  (see Figures C6 and CIO)
show an increase in the volatilization component of these compounds,  indicating a
slight departure from equilibrium.  Lakes Michigan and Erie show net inputs of these
two  pesticides, with gas  absorption being almost twice as much as volatilization.
Lake Superior shows net volatilization of a-HCH and c/s-chlordane.

trans-Chlordane  still shows  great  variability  across the basin.  Lakes Superior and
Erie show net volatilization for this  compound, with volatilization exceeding net in-
puts by  almost nine times in Lake Superior in 1998. Lake Huron shows that net in-
puts exceed net outputs of rram--chlordane, while Lakes Michigan and Ontario show
the compound is near equilibrium.

Particle  phase concentrations of all pesticides (except for p,p'-DDE)  are only meas-
ured at  Lakes  Superior, Erie, and  Michigan.   The figures in  Appendix C, however,
clearly show that dry deposition accounts for a small fraction, 20%-30% at most, of
the net input of these compounds to the Great Lakes.

For the  most part, 1997 and 1998  loadings show the same  results.  There are, how-
                                      10

-------
ever, a few notable differences between the two years.  In Lake  Superior,  relative
volatilization fluxes for dieldrin and  rram--chlordane increased dramatically, as did
the dieldrin volatilization from Lake Ontario in 1998.  Since volatilization fluxes are
similar for the two years, net inputs must have decreased over time in these lakes.

Only three in-use pesticides are reported here:  y-HCH (lindane), a-endosulfan, and
endosulfan sulfate.  No HLC  could be found for endosulfan sulfate,  so there are no
volatilization or gas absorption estimates available. Downward fluxes for these pesti-
cides range from 0.05 ng/m2/day to 40 ng/m2/day, about twice as much as the highest
banned pesticide downward flux.  Volatilization fluxes for y-HCH  and a-endosulfan
range from -0.004 to -4.3 ng/m2/day, almost 10 times lower than some banned pesti-
cide volatilization fluxes  and, on average, half as much as total downward fluxes of
these compounds.  Since  these compounds are  still in use, we would expect  their in-
puts to the lakes to far exceed their outputs from the lakes.  Figures Cl through CIO
demonstrate this nicely.  Inputs of these chemicals are dominated by gas absorption
on Lakes Superior, Michigan, and Erie.  This is especially true for a-endosulfan on
Lakes Michigan and Erie, where areas growing crops that are routinely sprayed with
this substance are often found near the sites.  y-HCH is mainly dominated by wet
deposition on Lakes Huron and Ontario.  Conversely, a-endosulfan inputs are led by
gas absorption on these two lakes.

S.a.ii. PCBsand HCB

PCBs and HCB are organochlorine  commercial chemicals whose uses  have been
banned. HCB is also banned from use  as a pesticide, but it is still released  into the
atmosphere as a byproduct  of some  chemical manufacturing processes.   Downward
fluxes for these chemicals range from 0.02 ng/m2/day to  11 ng/m2/day across the ba-
sin. Volatilization fluxes range from  -0.03  ng/m2/day to -34 ng/m2/day, with suite-
PCB fluxes higher than those of HCB.  Interestingly, suite-PCB volatilization fluxes
tend to increase from west to east across the basin (see Figure 2).
                                      11

-------
n -,
c .
-o
-in -


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c
X oc; .
3
0/-v

oc .
-GO


tt)
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Q)
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O
CQ'
CD






















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13






















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Figure 2. 1997 annual suite-PCB volatilization fluxes (ng/nf/day) for each lake


Dry deposition is not measured for any of these compounds because concentrations
were found to be insignificant in this phase. PCBs were also not measured in the pre-
cipitation phase on Lakes Huron and Ontario.  Given these omissions, it is  hard to
make comparisons regarding the fractions of the total deposition across the region,
but some trends  are evident.  Gas absorption is the dominant downward loading in
Lakes Superior, Michigan, and Erie.  Downward loadings at Lake Erie show a par-
ticularly strong dependence on gas absorption, while Lakes Superior and Michigan
show a stronger balance between gas absorption and wet deposition.

Suite-PCB shows a net loss from the lakes, except  for Lake Michigan in 1998. This
means that the lakes are acting as a source of PCBs to the atmosphere.  Individual
congeners, however, are acting slightly differently.  PCB 52 is close to equilibrium in
Lake Ontario, but in the other four lakes the water is a net recipient of this congener.
In fact,  Lakes Superior, Michigan,  and Erie show considerably  more atmospheric
depositions of PCB 52 than volatilization, by up to 30 times.

HCB is near equilibrium in all of the lakes except for Lake Ontario, where it has a net
loss from  the water.  Fluxes for HCB were  well above individual PCB congener
fluxes, but were up to 5 times lower than suite-PCB fluxes.
S.a.iii. PAHsand Metals

The PAHs and metals measured by IADN are currently emitted into the atmosphere
of the Great Lakes as byproducts of anthropogenic activity.  Since metals  are rela-
tively nonvolatile, gas absorption is not measured. As in indicated in Table A3, met-
als data are not available for Lakes Superior, Michigan, or Erie.
                                      12

-------
Downward fluxes for PAHs range from 0.3 ng/m2/yr to 530 ng/m2/day. Volatilization
fluxes range from -0.00001 to -240 ng/m2/day.  The individual PAHs show strikingly
different deposition patterns.  Deposition of the lighter PAH phenanthrene is domi-
nated by gas absorption, while that of pyrene is more evenly  split between wet and
dry deposition and gas absorption.  The heavier PAH inputs are dominated by wet
and dry deposition.  Interestingly, dry deposition of the heavier PAHs appears to have
increased in Lakes Michigan and Erie from 1997 to 1998. Where water concentration
data are available, volatilization of PAHs is almost always less than net inputs.  As
with the in-use pesticides, this is to be expected.

Fluxes for metals range from 13 to 840 ng/m2/day for dry deposition and from 130 to
5400 ng/m2/day for wet deposition. Fluxes for these substances are much higher than
those for pesticides, PCBs, or HCB.  The wet deposition flux of Pb averages 20 times
higher than that of Cd.   Though Pb still has the  highest dry deposition values, its
fluxes are closer to those of the other metals than its wet deposition fluxes.
3.b. 1992-1998 Flows (kg/yr)

In an effort to fulfill the goals of IADN as laid out in the introduction, it is important
to look at both spatial and temporal trends from all possible angles. Because the units
and therefore the results are more tangible, the most telling means of looking at tem-
poral trends is by use of flows in  kg/yr.  The flow tables can be found in Appendix D,
Tables D1-D5.  The tables contain  loadings data from  1992 through  1998.  The col-
umns represent wet and dry deposition, net gas exchange, and total deposition.  In
most cases, the total deposition is the sum of the three aforementioned components.
However, deposition from the particle phase was assumed to be negligible for many
species  and  measurements were rot made at the Canadian sites  for organochlorine
pesticides and PCBs.  Analysis  of PCBs as well as DDE and HCB in the particle
phase was ended in 1996 at the U.S. sites.  In addition, dry deposition data for pesti-
cides and PCBs were not included  in 1996 estimates for the U.S. sites. Table A3 in
Appendix A illustrates these missing data. In the cases mentioned above, total depo-
sition is the sum of all three components when present,  otherwise only wet deposition
and total gas exchange are summed.
S.b.i.  Organochlorine Pesticides

In a few cases, wet deposition is decreasing over time.  In Lake Huron, a-HCH has
dropped by over 50% in the last two years. A decreasing trend is also seen in Lake
Erie.  Although currently in use, y-HCH (lindane), shows a decrease in wet deposition
in Lakes Michigan and Erie over the sampling period, though the trend over Lake
Michigan is somewhat erratic.  Annual precipitation totals for these lakes have either
remained fairly constant or slightly increased,  indicating that precipitation amounts
are not playing a significant role in the decreasing trends of these pesticides.
                                      13

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Few distinct trends are discernable for dry deposition flows. However, dieldrin flows
show an overall increase from 1992 to 1998 in Lakes Superior and Michigan.  Where
they are measured, these particle phase flows are small compared to net gas exchange
and even wet deposition, justifying the  discontinuation of these measurement at the
Canadian sites.

In most  lakes,  net gas  exchange  is the  dominant process.   For Lake  Superior,
volatilization of a-HCH began between 1994 and 1995 and has been increasing since
then, from -230 to -470 kg/yr. Conversely, dieldrin has been showing a decrease in
its flow out of the Lake Superior.  After a series of slight decreases, lindane showed
net volatilization for the first time in 1998 in Lake Superior, but the total deposition is
still positive due primarily to wet deposition.  Nearly the opposite of Lake Superior,
Lake Michigan shows an increase in gas exchange to the lake between 1994 and 1995
for a-HCH and is joined by Lake Erie as the only lakes still showing  net absorption
ofa-HCH.

Total deposition typically mirrors the trends seen in net gas exchange.  Exceptions to
this are the HCHs in Lakes Huron and Ontario as well as />,/>'-DDT in Lakes Huron,
Erie, and Ontario, where wet deposition contributes as much, if not more, to the total.
S.b.ii. PCBsand HCB

Lakes Huron, Erie and Ontario continuously depict volatilization for HCB, with Lake
Ontario having the most pronounced temporal trend. Flows out of this lake decreased
from -160 kg/yr in 1992 to -21 kg/yr in 1998.

For all lakes with available data, 1997 and  1998 showed a decrease for both wet
deposition and net gas exchange of total PCBs.  The increase in the!998  wet deposi-
tion flux  of suite-PCB over Lake Michigan from  1997 values may be due to signifi-
cantly increased precipitation amounts that year.  Net gas exchange flows  for total
PCBs show net volatilization consistently  over time, although all lakes show a trend
towards equilibrium for this process.  Individual congeners in most lakes also show
the same  trend towards air-water equilibrium.
S.b.iii. PAHs and Metals

Unlike nearly all other species monitored by IADN, PAHs and metals are still emitted
into the atmosphere from several anthropogenic sources.  Because of this, trends tend
to be more stagnant or variable over time, with no clear increasing or decreasing pat-
tern in the flows.

The lakes on which metals are measured, Lakes Huron and Ontario, have seen a de-
crease in flows for wet deposition of cadmium and lead from 1992 through 1996.  In
                                      14

-------
fact, wet deposition flows of lead on Lake Huron have dropped from 100,000 kg/yr to
28,000 kg/yr.  In all cases, this trend was reversed with higher flows for 1997 and
1998.  Annual precipitation  over all years has remained fairly steady at both lakes.
Dry deposition of metals does not follow much of a trend, but rather remains at simi-
lar levels throughout the years.
3.c. Temporal and Spatial Flux Trends (1992-1998)

To get a complete picture of the trend comparison, fluxes (ng/m2/day) must also be
analyzed.  Being independent of lake area, they provide an excellent means of doing
spatial analysis.  Graphs of the annual fluxes can be found in Figures El through El 5
in Appendix E.  The graphs on each page are organized to include one compound
group and one deposition component. For gas exchange  and total flux, upward bars
indicate flow into the lake and bars pointing downward indicate volatilization.

The uncertainties in gas exchange fluxes have proven to be very large, especially near
equilibrium. To circumvent this problem, fugacity ratios  have  been used to examine
air-water equilibrium.   As mentioned, the direction of gas exchange can change from
flux into to flux out of the water. The fugacity is a measure of the tendency of a sub-
stance to escape from the phase in which it resides, with phases  in equilibrium having
equal fugacities (Mackay, 1991).  Because  the mass transfer coefficient is the  same
for the diffusive transport in both directions, the ratio of gas exchange mass fluxes as
calculated for the loadings report is interchangeable with  the ratio of fugacities. Fu-
gacity ratios reported in Table  Fl  in Appendix F are the ratio of air over water. Ra-
tios greater than one indicate absorption and ratios less then one indicate volatiliza-
tion.  A ratio of 1 indicates that equilibrium has been reached.  Table Fl contains fu-
gacity ratios from 1992-1998 for all species reported and is organized by lake.
S.c.i.  Organochlorine Pesticides

Wet deposition fluxes for a-HCH are decreasing over time in Lakes Ontario and Erie,
while dieldrin wet  deposition fluxes  decline over Lakes Michigan and Erie. Wet
deposition  fluxes for y-HCH at Lakes Huron and Ontario, however, do not follow
this declining trend. For Lake Ontario, 1997 and 1998 wet deposition fluxes are simi-
lar to 1992 and 1993 fluxes.  y-HCH  at Lake Huron has been at similar levels for the
past five years. Fluxes of both y- and a-HCH also seem to be quite higher at  these
lakes  as  well.  The magnitude of p,p'-DDD  wet deposition fluxes are  comparable
across the basin over time while/>,/>'-DDT fluxes show more variability both spatially
and temporally.  Meteorological data  do not indicate that precipitation averages  are
affecting these trends.

For all three lakes in which the particle phase is collected and measured, dieldrin con-
sistently  has the largest dry  deposition flux over time.  With the exception of p,p'-
                                      15

-------
DDT steadily decreasing at Lake Erie and the variability in annual fluxes of dieldrin
and a-HCH across the basin, the majority of the other pesticide dry deposition fluxes
are relatively constant.

Gas  exchange of dieldrin at Lake Ontario is consistently the largest flux observed,
indicating net volatilization of this pesticide. Also of note is the decreasing trend of
y-HCH absorption in Lake Erie and Michigan.  The graphs, and to a greater extent the
fugacity ratio of 0.92, suggest that  y-HCH  began volatilizing for the first time  in
Lake Superior in 1998.

While not included  in the graphs, the currently in-use pesticide a-endosulfan is pre-
sented in the fugacity  table  with ratios ranging from 530 to 6,600 for Lakes Erie and
Ontario.  These fugacity ratios dwarf the values for the banned pesticides, suggesting
that  gas absorption  is  still the dominant mechanism  of gas exchange for this in-use
pesticide.  Fugacity  ratios for other pesticides show some trends over time.  Ratios for
dieldrin are much less than one in all lakes and have been fairly constant over the
years.  rram--Nonachlor ratios have also been constant over the past four years for
each lake.  Total flux trends follow gas exchange trends closely.
S.c.ii. PCBsand HCB

Not much is discernible over time for the wet deposition of individual PCB conge-
ners.  In fact, wet deposition fluxes are similar over time and in magnitude on Lakes
Superior, Michigan, and Erie.  The homogeneity of data between these lakes is evi-
dence for the atmospheric ubiquity of PCBs.   Suite-PCB fluxes on all lakes except
Lake  Superior are, however, decreasing  over time.  Although recent comparisons
cannot be made for Lakes Huron and Ontario because of a lack of data, they do show
the largest suite-PCB wet deposition fluxes across the basin. Lake Erie seems unique
in that all PCBs measured there reached peak fluxes in 1995 and then decreased in the
following three years.

Lake Ontario consistently has the largest PCB fluxes and is the only lake that shows
volatilization for all congeners for all years. For most years though, PCBs across the
basin  show net gas exchange to be in the direction of volatilization. In Lakes Supe-
rior and Huron, gas exchange fluxes are near equilibrium for  some individual conge-
ners.  This is also seen in the fugacity table as values are near one.  PCB 52 has gone
from volatilization to absorption in 1997 for all lakes but Lake Ontario.  In the case of
Lakes Michigan and Erie, the fugacity ratios for PCB 52 are  quite high in 1997 and
1998, ranging from 12 to 32.  Total fluxes for PCBs also mirror net gas exchange
fluxes both temporally and spatially, but, more importantly, they indicate how signifi-
cant the process of air-water exchange is in the fate of PCBs in the Great Lakes.
                                      16

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S.c.iii.  PAHsand Metals

As  previously mentioned, there is not much of a temporal trend for PAHs in wet
deposition.  However, there is a rather strong spatial trend.  From west to east, the
fluxes  of  all of the PAHs  measured increase.  For example, the phenanthrene wet
deposition flux in 1993  increases from approximately 6 ng/m2/day in Lake Superior
to approximately 78 ng/m2/day in Lake Ontario. Whether this is merely due to the lo-
cation  of the sites or if it is result of increased urbanization from west to east in the
Great Lakes basin remains to be seen.  Much the same can be said for the analysis of
dry deposition fluxes.

In all lakes  but Lake Superior, data are too  spotty to look at  trends in PAH gas ex-
change. Phenanthrene from 1992 to 1994 and pyrene in 1994 are the only PAHs to
exhibit any volatilization from this lake.  Indeno[l,2,3-cJ]pyrene, a relatively heavy
PAH which is not on the flux graphs, has some very high fugacity ratios for Lakes
Superior and Erie.  The fugacity ratios  for the sum-PAH for these lakes are also
greater then one, which supports the idea  that the bulk of currently-emitted pollutants
are still entering the Great  Lakes through gas  absorption.  Because of a lack of gas
exchange data, it is also hard to assess any total flux trends.

The wet deposition of Cd and Pb in Lakes Huron and Ontario in 1997 and 1998 re-
verses  the trend of decreasing fluxes from 1992 to 1996. Between the two lakes, the
magnitude of wet and dry deposition fluxes  are quite similar.  Dry deposition seems
to follow no trend at all, either through time  or between the lakes.  These fluxes have
remained relatively constant over time for each metal.  Total fluxes for metals mirror
wet deposition trends,  indicating that this  is the dominant process  for depositing met-
als to the Great Lakes.  This is not surprising since wet deposition fluxes are up to six
time greater than dry fluxes.
3.d. Urban Impacts

One of the major sources of error in the loadings calculations is that IADN uses data
from one  remote sampling site to characterize each lake (Hoff, 1994; Hillery et al.,
1998).  Research suggests that spatial variability exists for many compounds across
any one lake (Achman et al., 1993; Monosmith et al., 1996). In particular, it has been
shown  that urban areas have  increased levels of deposition to the Great  Lakes as
compared to background levels (Offenberg et al., 1997; Simcik et al., 1997; Zhang et
al., 1999;  Franz et al.,  1998).  This implies that loadings calculated using  only  data
from a remote  sampling site might  grossly underestimate  the true  deposition to the
entire lake.  Given the many urban centers that exist in the Great Lakes region, there
is the potential for many urban impacts on loadings estimates to the Great Lakes.
                                      17

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IADN operates a satellite station in the urban center of Chicago at the Illinois Institute
for Technology (IIT) campus.  In the 1995-1996  loadings report, Galarneau et al.
(2000) used concentration data from Chicago for 1996 to prepare loadings estimates
for the city and then compared those results to estimates from Sleeping Bear Dunes,
lADN's master station on Lake Michigan, to determine the impact of the urban center
on lakewide loadings.

The purpose of the urban impacts assessment in the 1995-1996 loadings report was to
establish a base for estimating urban impacts for all major cities across the entire ba-
sin.  This work will  be  carried out in the  1999-2000 loadings report.  We have de-
cided, however, to continue with the work of Galarneau et al. (2000) here by perform-
ing the same calculations from the 1996 data on the 1997 and 1998 Chicago and Lake
Michigan data in an effort better understand urban impacts and trends over time in
comparison to loadings trends at a remote site.

Water concentration  data  was  not available for  Lake Michigan for dieldrin, a-
endosulfan, and all of the PAHs.  In order to have a complete picture of the loadings
estimates, lake water concentrations from Lake Erie were used in place  of the missing
data.

Flux calculations were  first made for all  substances at both Sleeping Bear Dunes
(SBD) and  Chicago.   These estimates were calculated as if they  occurred over adja-
cent waters, just as the loadings for the  master stations were calculated.  The results
for wet and dry deposition, net gas exchange, and total mass flux  are shown in Table
2 for 1996-1998.

We can see from Table  2 that Chicago  fluxes for most substances  are much greater
than fluxes found at  Sleeping Bear Dunes,  a site that is representative of regional
background (rural) concentrations.  The total mass flux for PAHs  at Chicago is al-
ways  positive, indicating net inputs of these compounds into the  lake from this site.
They  are also 40 to  190  times greater  than Sleeping Bear Dunes PAH  total mass
fluxes. In fact, Chicago  PAH fluxes in all deposition categories far exceed  those from
Sleeping Bear Dunes.

PCBs follow the same  trend, with one striking difference  from the  master  station
fluxes.  PCB net gas exchange fluxes are negative  at Sleeping Bear Dunes, with the
exception of PCB 52, indicating the  lake  is a source of these compounds to the at-
mosphere.  At Chicago, all net gas exchange fluxes are positive, indicating  gas ab-
sorption is the dominant  process here.  This is not unexpected since PCBs  are mainly
an urban pollutant.

Pesticides,  on the other hand, show  much ess disparity in  flux values between the
two sites. In fact, the dry deposition of a-HCH and a-endosulfan is greater at Sleep-
ing Bear Dunes than  Chicago. This is because many pesticides are often used for ag-
ricultural purposes, which  take place in the more rural areas  of a state.  Dieldrin,  cis-
and fram'-chlordane, and p,p'-DDE show  net volatilization fluxes  at Sleeping Bear
                                      18

-------
Dunes but net absorption at Chicago.

While differences in flux magnitudes are interesting between the two sites, it is also
interesting to note the trends over the past three years at these sites. Dieldrin fluxes
have remained fairly constant across time at Sleeping Bear Dunes, and a similar trend
can be seen at Chicago, though 1997 showed an increase in total mass flux. As HCB
gas exchange and total mass fluxes have increased over time at Sleeping Bear Dunes,
they have decreased  at Chicago.  Total mass flux values of suite-PCB at Sleeping
Bear Dunes have decreased dramatically from 1996 to 1998 and have even gone from
the lake being a net source of PCBs to it being  a net receiver of the contaminants.
Suite-PCB total mass flux values at Chicago  have held steady over time. PAH wet
deposition has been variable at  Chicago with an overall doubling in flux from 1996
to 1998, while net gas exchange has greatly decreased there.  Conversely, Sleeping
Bear Dunes, while  also exhibiting some variability over the years, shows fairly con-
stant wet deposition fluxes from 1996 to 1998, while PAH net gas exchange at this
site shows a decrease for phenanthrene but a slight increase for sum-PAH.  Though
temporal trends for some compounds mirror each other at both sites, more often the
trends differ between lADN's urban and remote sites on Lake Michigan.
                                      19

-------
Table 2. Mass fluxes (ng/m2/day) of atmospheric deposition at Sleeping Bear
Dunes (SBD), an IADN master station, and Chicago from 1996-1998
Species
a-HCH
y-HCH
dieldrin
o_
endosulfan
cis-
chlordane
trans -
chlordane
trans -
nonachlor
p,p'-DDD
p,p'-DDE
pp'-DDT
HCB
PCB18
PCB44
PCB52
PCB101
suite-PCB
phenan-
threne
pyrene
B[b+k]F
B[a]P
l[1,2,3cd]P
sum-PAH
Year
1996
1997
1998
1996
1997
1998
1996
1997
199R
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
199R
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
199R
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
199R
1996
1997
1998
1996
1997
1998
Wet Deoosition
SBD
0.71
1.9
0.8
0.31
1.5
0.61
1.4
1.2
1 5
0.65
0.69
0.49
0.18
0.47
0.52
0.45
0.052
0.058
0.045
0.037
0.042
0.084
0.017
n 14
0.19
0.12
0.13
0.43
0.2
0.14
0.043
0.035
0.039
0.08
0.039
n nfifi
0.046
0.062
0.13
0.1
0.079
0.091
0.064
0.051
0.082
2.3
1.2
1.8
10
15
8.5
6.8
11
6.4
12
16
13
4
5.7
4 7
6.3
9.4
6.6
23
31
24
Chicaao
3.2
3.1
1.7
2.9
4.8
3.6
4.2
7.1
39
1.4
2.4
3.3
0.11
8.4
1.2
1.5
0.78
1.1
0.46
0.53
0.31
0.38
0.86
fl?R
1.3
1
1
3.9
3.8
3.1
0.11
0.17
0.17
0.24
0.25
059
0.27
0.43
0.89
0.38
0.45
0.86
0.44
0.52
1.2
13
11
27
330
860
790
400
910
760
390
930
900
210
540
4fifl
230
440
390
840
1900
1700
Drv Deoosition
SBD
0.16
0.043
0.11
0.089
0.73
087
1.7
6.6
0.12
0.15
0.069
0.085
0.054
0.039
0.036
0047
-
0.052
0.093
-
-
-
-
-
-
5
4.6
5.8
5.1
4.7
7.1
9.2
8.7
14
1.9
2.3
4 1
4.8
4
8.4
16
15
26
Chicaao
0.023
0.019
0.25
0.093
5.3
4 4
1.3
1
2.8
2.7
0.62
0.65
0.22
0.14
0.13
n 15
-
1.5
0.82
-
-
-
-
-
-
180
220
140
340
320
220
340
330
320
130
160
110
180
180
180
650
670
600
Net Gas
SBD
14
14
9.7
5.1
7.2
8.9
-10
-6.9
-9 7
17
39
40
-0.15
0.1
-0.21
-0.14
-0.017
-0.23
-0.7
-0.77
-0.79
0.22
0.17
0?5
-0.13
-0.073
-0.57
0.26
0.62
0.66
0.39
0.74
1.2
-1.1
-0.39
-o?fi
-1
-0.52
-0.52
0.1
0.45
0.52
-0.43
-0.24
-0.2
-15
-3.2
-1.6
-340
33
-15
-45
-0.84
0.86
2.6
4.1
4.8
-0.12
0.65
fl4R
0.96
1.3
1.8
3.4
6
7.1
Exchanae
Chicaao
32
18
7.2
14
11
11
6.5
11
2
22
25
38
5.6
6.8
4.6
5.1
5
3.6
0.1
-0.027
-0.21
0.78
1.3
1 4
4.4
3.2
3
7.6
5.1
5
2.6
1.9
1.3
2
2.3
77
6.7
5.7
4
8.3
8.1
7.1
4.4
4.8
4.7
97
80
76
17000
8900
6500
2100
1300
1000
70
84
24
17
25
fifl
23
22
7.7
110
130
38
Total M
SBD
15
16
11
5.4
8.8
9.6
-8.6
-5
-7 3
18
41
47
0.03
0.69
0.46
0.31
0.1
-0.087
-0.66
-0.68
-0.71
0.3
0.22
044
0.06
0.047
-0.44
0.69
0.87
0.89
0.43
0.78
1.2
-1
-0.35
-n 7
-0.95
-0.46
-0.39
0.2
0.53
0.61
-0.37
-0.19
-0.12
-13
-2
0.2
-330
53
-0.7
-33
15
14
24
29
32
5.8
8.7
R R
12
15
17
42
52
57
ass Flux
Chicaao
35
21
8.9
17
16
15
11
23
10
23
29
42
5.7
18
8.5
6.6
6.4
5.4
0.56
0.72
0.24
1.2
2.3
1 R
5.7
4.2
4
12
10
8.9
2.7
2.1
1.5
2.2
2.6
7 R
7
6.1
4.9
8.7
8.6
8
4.8
5.3
5.9
110
91
100
18000
10000
7400
2800
2500
2000
800
1300
1200
360
730
570
430
640
580
1600
2700
2300
                                   20

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To further explore the effect of urban inputs on lakewide loadings, we followed the
lead of Galarneau et al. (2000) and assessed whether the larger Chicago fluxes were
significant across the entire lake.  To do this, the impact Chicago might have over the
whole  lake was estimated by using an urban plume effect that assumes deposition
from Chicago extends only over a small sub-area of Lake Michigan.  This sub-area
corresponds to 1.7% of the total lake area for wet and dry deposition, and 3.5% of the
total lake area for gas exchange  (Galarneau et al., 2000, p. 14).  A temporal compo-
nent was also added to account for the time that air is flowing from the city over the
lake and can thus impact loadings. Then, the increase in lakewide flows as a result of
the  inclusion of the urban flows with the regional data was calculated as a percent
(urban effect).  The results of these calculations are shown in Table 3. Negative ir-
ban  effect  percentages indicate  that the background  (BG) lakewide volatilization
flows are decreased by including the urban inputs. Background (BG) flows refer to
Sleeping Bear Dunes data.

Urban  inputs have a minor lakewide  effect for most pesticides.  There does seem to
be a large effect, however, on cis- and  rram--chlordane net gas exchange  and total
mass flows.  Net gas exchange of ^raw^-chlordane over the Chicago lake sub-area will
drastically change  lakewide volatilization and markedly increase total mass flows.
The  same is true for c/s-chlordane, though to a lesser  extent.  p,p'-DDE also shows
strong  urban effects, with lakewide volatilization being greatly reduced and total mass
flows being increased.

PCBs show a varied urban effect. While urban inputs do not impressively affect wet
deposition flows, stronger effects are  seen in gas exchange and total  mass flows. For
example, in 1998, inclusion of Chicago  flows will decrease suite-PCB volatilization
by as much as 53% while they will  increase total flows to the entire lake by over
500%.  In the same year, wet deposition flows will only increase 8.9% by incorporat-
ing  Chicago into the lakewide loadings.  Similar disparities in depositional effects are
seen in 1996 and 1997, though not to the same extent as total flow increases in  1998.
Since PCBs had mainly urban uses, it is not surprising that an urban site would affect
PCB flows to such  a great extent.  PAHs, which have many current sources in Chi-
cago, show  large urban  effects  in all  deposition categories as compared to  other
chemicals.

With three years of data for Chicago loadings,  we wondered if urban effects were
consistent or  changed over time.  For chemicals  with similar urban and background
loads,  urban effects can change  radically over time.  For example, p,p'-DDE total
mass flows for both sites tend to track each other very well, so urban effect values are
sensitive  to small changes, such  as in 1997.  Consistently high background flows as
compared to urban hputs generally  have  smaller urban effects over time that are
more resilient to change, such as  a-endosulfan urban effects for total mass flows and
net gas exchange.
                                      21

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Table 3. The effect on lakewide loadings of adding flows from Chicago to master station estimates of regional background
(BG) flows from Sleeping Bear Dunes.
Species
ctHCH
Y-HCH
dieldrin
a-
endosulfan
c/s-
chlordane
trans-
chlordane
trans-
nonachlor
p,p'-DDD
p p '-DDE
pf'-DDT
HCB
Year
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
Wet Deoositior
BG
(kg/vr)
15
40
17
6.6
31
13
30
24
31
14
15
10
3.9
9.9
11
9.6
1.1
1.2
0.95
0.78
0.89
1.8
0.36
2.9
3.9
2.5
2.7
9
4.3
3
0.91
0.75
0.83
Chicago
(kfl/vr)
0.41
0.37
0.24
0.34
0.51
0.47
0.52
0.85
0.53
0.16
0.28
0.45
0.012
0.88
0.12
0.16
0.1
0.17
0.064
0.068
0.04
0.05
0.1
0.029
0.16
0.12
0.14
0.53
0.42
0.43
0.014
0.018
0.021

Urban
Effect
2.7%
0.9%
1.4%
5.2%
1.6%
3.6%
1.7%
3.5%
1.7%
1.1%
1.9%
4.5%
0.3%
8.9%
1.1%
1.7%
9.1%
14.2%
6.7%
8.7%
4.5%
2.8%
27.8%
1.0%
4.1%
4.8%
5.2%
5.9%
9.8%
14.3%
1.5%
2.4%
2.5%
Drv Deoosition
BG
(kfl/vr)
3.4
0.91
2.3
1.9
15
18
36
140
2.5
3.2
1.5
1.8
1.1
0.82
0.76
0.99
-
1.1
2
-
Chicago
(kfl/vr)
0.0028
0.0022
0.029
0.011
0.63
0.53
0.15
0.12
0.31
0.31
0.075
0.075
0.027
0.017
0.015
0.016
-
0.17
0.092
-

Urban
Effect
0.1%
0.2%
1.3%
0.6%
4.2%
2.9%
0.4%
0.1%
12.4%
9.7%
5.0%
4.2%
2.5%
2.1%
2.0%
1.6%
-
15.5%
4.6%
-
Net Gas Exchanae
BG
(kfl/vr)
300
300
200
110
150
190
-220
-150
-210
360
830
830
-3.3
2.2
-4.5
-3
-0.36
-4.9
-15
-16
-17
4.7
3.5
5.3
-2.7
-1.5
-12
5.6
13
14
8.3
16
26
Chicago
(kfl/vr)
8
4.2
1.5
3.2
2.4
2.5
1.6
2.4
0.41
5
5.7
8.3
1.3
1.6
1
1.2
1.2
0.85
0.023
-0.0048
-0.049
0.2
0.3
0.31
1
0.74
0.71
1.8
1.2
1.1
0.66
0.46
0.33
Urban
Effect
2.7%
1 .4%
0.8%
2.9%
1.6%
1.3%
-0.7%
-1.6%
-0.2%
1 .4%
0.7%
1.0%
-39.4%
72.7%
-22.2%
•40.0%
-333.3%
-17.3%
-0.2%
0.0%
0.3%
4.3%
8.6%
5.8%
-37.0%
-49.3%
-5.9%
32.1%
9.2%
7.9%
8.0%
2.9%
1.3%
-f
BG
(kfl/vr)
320
340
220
120
180
200
-190
-110
-160
370
880
980
0.6
15
9.7
6.6
2.2
-1.9
-14
-14
-15
6.5
4.6
9.2
1.2
1
-9.3
15
18
19
9.2
17
27
otal Mass Flow;
Chicago
(kg/vr)
8.4
4.6
1.7
3.5
2.9
3
2.1
3.9
1.5
5.2
6.1
8.9
1.3
2.8
1.4
1.4
1.4
1.1
0.087
0.09
0.008
0.25
0.42
0.36
1.2
0.86
0.85
2.3
1.8
1.6
0.67
0.48
0.35
s
Urban
Effect
2.6%
1.4%
0.8%
2.9%
1.6%
1.5%
-1.1%
-3.5%
-0.9%
1.4%
0.7%
0.9%
216.7%
18.7%
14.4%
21.2%
63.6%
-57.9%
-0.6%
-0.6%
-0.1%
3.8%
9.1%
3.9%
100.0%
86.0%
-9.1%
15.3%
10.0%
8.4%
7.3%
2.8%
1.3%
                                                       22

-------
Table 3 (continued)
Species
PCB18
PCB44
PCB52
PCB101
suite-PCB
phenan-
threne
pyrene
B\b+k]F
B[a]P
in.2.3-cdip
sum-PAH
Year
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
1996
1997
1998
Wet Deoositior
BG
to/vrt
1.7
0.82
1.4
0.97
1.3
2.8
2.2
1.7
1.9
1.4
1.1
1.7
48
25
38
220
320
180
140
220
130
258
338
278
84
120
89
130
200
140
480
650
510
Chicago
fka/vrt
0.029
0.03
0.075
0.033
0.057
0.11
0.047
0.054
0.11
0.056
0.063
0.15
1.6
1.3
3.4
46
95
100
57
99
98
53
99
118
29
57
58
32
47
51
110
200
230

Urban
Effect
1.7%
3.7%
5.4%
3.4%
4.4%
3.9%
2.1%
3.2%
5.8%
4.0%
5.7%
8.8%
3.3%
5.2%
8.9%
20.9%
29.7%
55.6%
40.7%
45.0%
75.4%
20.5%
29.3%
42.4%
34.5%
47.5%
65.2%
24.6%
23.5%
36.4%
22.9%
30.8%
45.1%
Drv Deoosition
BG
fka/vrt
-
-
-
-
-
100
97
120
110
99
150
197
180
288
41
48
86
100
85
180
340
320
550
Chicago
to/vrt
-
-
-
-
-
23
26
16
43
39
24
42
39
35.8
15
18
12
22
21
21
79
79
68

Urban
Effect
-
-
-
-
-
23.0%
26.8%
13.3%
39.1%
39.4%
16.0%
21 .3%
21 .3%
12.4%
36.6%
37.5%
14.0%
22.0%
24.7%
11.7%
23.2%
24.7%
12.4%
Net Gas Exchange
BG
to/vrt
-24
-6.2
-5.5
-22
-8.20
-11
2.2
7.10
11
-9.1
-3.79
-4.3
-320
-51.4
34
-7200
700
-310
-950
-18
18
55
86
100
-2.4
14
10
20
27
37
72
130
150
Chicago
fkg/vrt
0.45
0.53
0.52
1.4
1.4
0.9
1.9
1.9
1.7
0.98
1.1
1.1
22
19
18
3800
2000
1500
500
300
230
18
19
5.7
4.e
5.5
1.6
6.;
4.9
1.8
29
29
9.1
Urban
Effect
-1.9%
-8.5%
-9.5%
-6.4%
-17.1%
-8.2%
86.4%
26.8%
15.5%
-10.8%
-29.0%
-25.6%
-6.9%
-37.0%
-52.9%
-52.8%
285.7%
-483.9%
-52.6%
-1666.7%
1277.8%
32.7%
22.1%
5.7%
-191.7%
39.3%
16.0%
31.5%
18.1%
4.9%
40.3%
22.3%
6.1%
Total Mass Flow
BG
fkg/vrt
-22
-5.4
-4.1
-21
-6.9
-8.2
4.4
8.8
13
-7.7
-2.7
-2.6
-270
-26
4
-6900
1100
-10
-700
300
300
510
610
670
120
180
190
250
310
360
890
1100
1200
Chicago
to/vrt
0.48
0.56
0.6
1.4
1.5
1
1.9
2
1.8
1
1.2
1.3
24
20
21
3900
2100
1600
600
440
350
110
160
160
49
81
72
60
73
74
220
310
310
s
Urban
Effect
-2.2%
-10.4%
-14.6%
-6.7%
-21.7%
-12.2%
43.2%
22.7%
13.8%
-13.0%
•44.4%
-50.0%
-8.9%
-76.9%
525.0%
-56.5%
190.9%
-16000.0%
-85.7%
146.7%
116.7%
21 .6%
26.2%
23.9%
40.8%
45.0%
37.9%
24.0%
23.5%
20.6%
24.7%
28.2%
25.8%
                                                         23

-------
Flow and flux estimates from 1996-1998 show that an urban center can have a significant
impact on lakewide loadings for certain chemicals.  These results further encourage the
use of urban data for future reports and also signal the need for more urban satellite sta-
tions in the IADN program.  Having precise measurements from urban centers  on all
lakes will hopefully facilitate the calculation of better, more exact loadings so that a more
complete picture of the Great Lakes can be formed.
4. Regional Deposition

Another property of flows (kg/yr) is that they are additive.  From the flow tables in Ap-
pendix D, the sum over all 5 lakes for each species for total deposition was calculated for
every year and can be seen in Table 4.  Chicago flows were not included in the sums be-
cause data was not available for all years and this was the only urban area for which we
had any data. Data for most urban centers around the Great Lakes basin would need to be
included in order to develop a regional  picture, and we do not have that information.  All
sums, except for the metals, represent values taken from three or more lakes.  The metal
sums include data from Lakes Huron and Ontario  only.  This table gives an approxima-
tion  of the background regional flows to the waters of the Great Lakes.    Table 4 also
shows x-intercept and r-squared values  for  the linear regression of flows (kg/yr) vs. time
(year). The  x-intercept values were found by setting the flow to zero for each regression.
These intercepts represent the approximate year when equilibrium for a given chemical
will  be reached in the Great Lakes.  X-intercept values for metals  approximate when in-
puts  (wet  and dry deposition) to the lakes  will be  zero.  These years are only estimates
and are taken directly from the regression parameters. Relative errors based on other re-
gression parameters are on average 37% for this term.
                                        24

-------
Table 4. Annual total deposition flows (kg/yr) to all of the Great Lakes.  Each an-
nual regional sum includes data  from  at  least three lakes.   R-squared  and  x-
intercept values are from  the regression of total deposition flows against year for
each species.  X-intercept values represent the year when equilibrium  (flow = 0
kg/yr) will be achieved.  All r-squared values shown are significant at the 95% con-
fidence level or greater.  Those that are not significant are represented by NS.
Species
a-HCH
Y-HCH
dieldrin
p,p'-DDD
p,p'-DDE
P,P'-DDT:
HCB
PCB 18
PCB44
PCB 52
PCB 101
sum-PCB
phenanthrene
pyrene
E[b+k]F
B[a]P
Pb
As
Se
Cd
Year
1992
950
1300
-960
17
-70
190
-130
-160
-59
-80
-55
-2900
-4500
2200
820
840
160000
17000
27000
9800
1993
560
800
-1400
28
-75
320
-94
-200
-64
-77
-49
-3100
-4400
2100
700
840
100000
13000
21000
46000
1994
980
870
-1300
30
-65
160
-160
-200
-72
-71
-46
-3100
-4800
1600
620
610
79000
10000
18000
3400
1995
540
510
-410
2.7
21
56
-26
-82
-65
-19
-16
-940
9500
4900
3700
1200
34000
4100
4300
2100
1996
310
420
-420
16
4
47
-27
-61
-16
16
0.6
-1300
3100
1700
2400
680
41000
6800
5600
2800
1997
240
540
-290
44
-13
90
-1.5
-30
-24
24
-1.5
-730
7100
2600
3000
1000
99000
2200
1200
4700
1998
-210
450
-370
25
-55
26
15
o o
-JJ
-28
22
-2.6
-690
5900
1800
2700
830
78000
2200
1000
6200

r-squared
0.785
0.736
0.628
NS
NS
0.620
0.741
0.772
0.579
0.893
0.861
0.779
0.605
NS
NS
NS
NS
0.882
0.894
NS
x -intercept
1998
2001
1999
NS
NS
1998
1997
1999
2001
1996
1997
1999
1994
TVS'
TVS
TVS
TVS
1998
1997
TVS
The difference between pollutants that have banned from use and those that are currently
used stands out quite clearly.  Throughout the years y-HCH, a currently-used pesticide,
almost always has the highest regional loading values other than the currently-emitted
PAHs and metals.  In 1994 and 1995, however, y-HCH flows were close to a-HCH val-
ues. The total deposition values for the banned chemicals dieldrin, p,p'-DDE, and HCB,
however, are negative, indicating that the lakes themselves are acting as sources of these
compounds to  the atmosphere.  Dieldrin  regional flows have been negative in all years
and have decreased by approximately a third from 1992 to 1998. This decreasing trend is
moving towards equilibrium, which is estimated to have been achieved around 1999.  In-
terestingly, p,p'-DDD and DDT  total regional flows have been consistently  positive
across time. This indicates that the  Great Lakes basin is still acting as a  sink for these
chemicals  that have been banned from use for over 20 years.  In fact, no significant trend
                                       25

-------
towards equilibrium could be found for p,p'-DDD.  Based on the previously mentioned
regression, however, p,p'-DDT should be very near equilibrium already.

The regional flows over time for both a- and y-HCH are shown in Figure 3.  a-HCH
shows a statistically significant decrease across the Great Lakes basin and has a net vola-
tilization for the first time in 1998.  Flows for y-HCH, on the other hand, have remained
relatively stable since their decrease in 1995. Again, this is probably because its use  is
restricted rather than banned. However, r-squared values indicate that y-HCH is showing
a real trend towards equilibrium and will achieve it around the year 2001.
             -400
                    1992   1993   1994  1995  1996  1997  1998
                                     Year
Figure 3.  Total flows of a- and y-HCH (kg/yr) over all Great Lakes

The observed decline in a-HCH has more meaning when viewed against larger trends in
HCH usage.  Li (1999)  surveyed usage of technical HCH on a global  scale from 1948
through 1997.  Technical HCH contains five isomers, of which 65% is the a-isomer and
14% is the y-isomer.  From Li's work, a plot of annual global usage was created from
1950 to 1995 (see Figure 4). It is estimated that during this period, approximately 10 mil-
lion tonnes of technical HCH was used.  It is apparent from the graph that three main de-
clines in global usage occurred.  The first began in the early seventies when countries
such as Canada (1971),  Japan (1973) and the United States (1976) banned usage.  An-
other major drop occurred in  1983 when China banned the use of this pesticide, and a
third decrease began in  1990  when the former  Soviet Union completely banned its use,
and India banned its use for agricultural purposes.
                                       26

-------
            400

            350


        •^  250
         (/)

         0  2°°
        "5  150
        5  100

             50

             0
              1950    1955   1960   1965
 1970   1975
Year
1980   1985    1990   1995
Figure 4. Global technical HCH usage in kilotons per year.  This figure is taken
from Li, 1999.


Data collected by IADN and reported as flows correspond to the tail end of Figure 4.
Given that technical HCH usage has been banned by some of the countries that used it
most, it is not  surprising that we are seeing decreasing atmospheric deposition to the
Great Lakes.  The downward trend observed in Figure 3  is probably due to the depletion
of HCH stores in the soil and vegetation.  Judging from Figure 4, we can expect to see
continuing decreases in HCH flows to the Great Lakes region.

As HCH flows to the Great Lakes have decreased, so have PCB total flows out of the ba-
sin (see Figure  5).  Between 1992 and  1998, PCB volatilization has  decreased dramati-
cally, with the  largest change occurring between 1994  and 1995 when flows  dropped
from -3100 kg/yr to -940 kg/yr.  With an r-squared of 0.779, sum-PCB flows are show-
ing a real trend towards equilibrium, and should have achieved it around 1999. The larg-
est contributors to this trend were Lakes Superior and Michigan, where total deposition
flows for total PCBs dropped by a factor of five and six, respectively.
                                       27

-------
                   1992
1993
1994
Year
1995
1996
1997
1998
          -3500
Figure 5. Total flow (kg/yr) of PCBs over all the Great Lakes from 1992-1998.  1997
and 1998 data represent suite-PCB while previous years represent total PCBs.


In general, the regional total deposition of PAHs has remained stable over the years. This
is further supported by  the  lack of a  significant trend in Table 4  for  most PAHs.
Benzo[6+£]fluoranthene appears to have increased since 1995, but this is most likely due
to the fact that lake water concentrations for this compound from  1992-1994 were for
benzo[£]fluoranthene only.  Phenanthrene, however,  stands out from the other PAHs.
Total regional flows for this currently emitted pollutant were net volatilization for 1992
through 1994, though one would expect the region to experience net inputs of this com-
pound since it is still released  into the atmosphere. It is important to keep in mind,  how-
ever, that water concentration  data for PAHs are lacking in most lakes for most years (see
Table A4), making true regional trends hard to assess.

Metals generally have the highest total flows into the lakes.  While flows for all metals
have decreased over time, they are still quite large. For example, lead inputs to the Great
Lakes basin in 1992 totaled 160000 kg/yr. By 1998, these flows had dropped to  78000
kg/yr, but they were still 13  times  higher than phenanthrene total deposition and 170
times  higher  than  y-HCH flows to the  entire region, also currently-used or produced
chemicals.  As with the PAHs, lead and  cadmium show no significant trend, but arsenic
and selenium do show significant declining trends. These results may be somewhat mis-
leading, however. No wet deposition estimates are available in 1997 and 1998 for arsenic
and selenium, but all previous years total deposition estimates from Table 4 include wet
deposition.  Given that wet deposition is on average four times higher than dry deposition
for these two metals, and assuming that wet deposition patterns would follow those of
lead and cadmium, that is an increase in 1997 and 1998, we can assume that a significant
portion of the regional total deposition estimate for arsenic and selenium is unaccounted
for in 1997 and  1998 in Table  4. Thus, while the estimates represent all available data for
arsenic and selenium in 1997  and  1998, they most likely do not represent true deposition
to the region. If precipitation-phase data had been collected, it is highly probable that de-
clining trends would not be significant for  arsenic and selenium just as they are for lead
                                       28

-------
and cadmium.
5. Conclusions

Downward fluxes for pesticides in 1997  and 1998 ranged from  0.01 ng/m2/day to 40
ng/m2/day, with in-use pesticides such as y-HCH accounting for the highest fluxes. Vola-
tilization fluxes for those pesticides banned from use were almost 10 times greater than
those for currently used pesticides, reaching  -37  ng/m2/day at their highest.  PCB and
HCB downward fluxes ranged from 0.02 ng/m2/day to 11 ng/m2/day across the basin.
Volatilization fluxes for these banned commercial chemicals were on the same order as
those for banned pesticides.  Suite-PCB volatilization fluxes increased from west to east
across the basin.   Downward fluxes  for PAHs  ranged from 0.3  ng/m2/day to  530
ng/m2/day with volatilization fluxes ranging from  -0.00001 to -240 ng/m2/day. Where
water concentration data are available,  volatilization of PAHs was almost always  less
than net inputs.  Fluxes  for metals ranged from 13 to 840 ng/m2/day for dry deposition
and from 130 to 5400 ng/m2/day for wet deposition.  Since the metals analyzed by IADN
are nonvolatile, they are  not measured in the gas phase. The PAHs and metals measured
by IADN are  currently  emitted through anthropogenic means into the atmosphere and
thus have downward (air to water) fluxes much greater than those of the pesticides and
PCBs that have been banned from use.
Current (1997-1998) fluxes (ng/m2/day) were compared across time and space to better
understand loadings trends in the Great Lakes.  Pesticide wet deposition fluxes seem to
be generally decreasing over time except for y-HCH at Lakes Huron and Ontario. Since
y-HCH is still in use, this trend is expected. Volatilization of dieldrin from Lake Ontario
is the largest pesticide flux observed.  The magnitude of PCB wet  deposition fluxes is
similar for Lakes Superior, Erie, and Michigan.  Lake Erie, however, seems  unique in
that all PCBs measured there reached peak fluxes around 1994 and 1995 and then de-
creased in the following three years.  Gas exchange of PCBs has been, for the  most part,
in  the  direction  of net volatilization consistently over time with only Lake  Michigan
showing signs of nearing air-water equilibrium. Wet and dry deposition of PAHs shows
no real temporal  trend, but spatial analysis indicates that fluxes have increased  from west
to east across the basin. Gas exchange fluxes for Lakes Superior and Erie for all PAHs
show net absorption over time.  Metal fluxes  for Lakes Huron and Ontario are similar
over the years with dry deposition showing no real trend and wet deposition decreasing
from 1992-1996  for Cd and Pb, then increasing in 1997 and 1998.

All of  the flows and fluxes  mentioned above  are based on  IADN master station data.
These stations are remote sites, one on each lake,  which measure what are considered to
be Great Lakes background contaminant levels.  However, spatial differences exist across
each lake for many of the compounds we monitor, particularly near urban areas, where
atmospheric deposition from  cities can be much greater than that from remote sites. In an
attempt to assess the impact of urban areas on lakewide loadings, and in accordance with
the 1995-1996 loadings report, deposit!onal data from  lADN's Chicago site were ex-
                                       29

-------
trapolated onto Lake Michigan loadings.  The impact of Chicago pollution on a small
sub-area of Lake Michigan was then compared to loadings calculated at the remote mas-
ter station.  Results demonstrate that urban inputs have a minor lakewide effect for most
pesticides.  There does, however, seem to be a large effect on cis- and rram--chlordane,
drastically changing lakewide volatilization and markedly increasing total mass loadings.
Urban inputs also have a strong effect on the net gas exchange of PCBs. PAHs, currently
emitted urban  pollutants,  show consistently  large urban effects in all  deposition  catego-
ries.

In an attempt to explore a more tangible means of examining the loadings results, esti-
mates were investigated on a Great Lakes basin-wide basis by summing the total  deposi-
tion flow (kg/yr) of each  substance over all five lakes for each year.  These sums give a
good approximation of the larger, regional atmospheric deposition to the  Great  Lakes.
Total deposition for a-HCH showed a decreasing trend, going from 950 kg/yr in 1992 to
-210 kg/yr in 1998.  Dieldrin and />,/>'-DDE, two  organochlorine pesticides banned from
use, had negative total deposition across time, indicating that the lakes are acting as a
source of these chemicals to the atmosphere.  Sum-PCB total deposition across the basin
also showed net volatilization for all years.  Even so, PCB flows out of the Great Lakes
have decreased dramatically over time, with the largest drop occurring between 1994 and
1995 when total PCB flows went from -3100 kg/yr to -940 kg/yr. PAHs and metals had
the largest regional deposition.  PAH flows  have, for the most part, remained stable
across time. While total  loads of metals to the Great  Lakes basin have decreased over
time, the region was still receiving 78000 kg of lead in 1998.

With seven years of data, IADN has been succeeding  at the task of determining the at-
mospheric loadings of toxic substances to the Great Lakes.  This biennial report helps to
further elucidate trends in the region and provide a more robust picture. Despite the vast
array of compounds measured by IADN, some general trends have emerged among them
over time.  Loads of banned pesticides and commercial chemicals have decreased over
the years,  with the lakes  themselves actually becoming the main source  of these sub-
stances to the atmosphere.  These trends also suggest that most of the restricted pesticides
and PCBs measured by IADN are approaching air-water equilibrium. For those chemi-
cals that are currently emitted, like PAHs, metals, and some pesticides, their loads have
remained relatively  constant  through time.   Furthermore, the temporal urban  effects
analysis in this report continues to raise concerns  about the impact of urban pollution on
the loadings to the Great Lakes.
                                       30

-------
Acknowledgements

Special thanks to the many people whose work supported the production of the IADN
loadings results.

•  Site operators on Lake Superior - Donald B. Keith and Patricia Keith (Eagle Harbor),
   Ron Perala (Brule River), Carl Nielsen (Sibley), Larry Barnett (Turkey Lakes)
•  Site operator and coordinator on Lake Michigan - Tom van Zoeren (Sleeping Bear
   Dunes), Nasrim Khalili (IIT- Chicago)
•  Site operators on Lake Huron  - Floyd Orford  (Burnt Island), Terry Romphf (Grand
   Bend)
•  Site coordinator on Lake Erie - Dr. Kim Irvine (Sturgeon Point), Gary Mouland (Pt
   Pelee), Tony Bucsis (Rock Point)
•  Site operator on Lake Ontario - Darrell Smith (Point Petre)

•  Karen Arnold and Matt O'Dell at Indiana University
•  Brian Martin, Jim Woods, Frank MacLean, Chris Green,  Andrew Elford, and Helena
   Dryfhout-Clark at the Centre for Atmospheric Research Experiments of Environment
   Canada's Meteorological Service of Canada
•  Nick Alexandrou, Ky Su, Richard Park, Kulbir Banwait, Art Tham, Cecilia Shin, and
   Murray Smith  at the Organics Analysis Laboratory of Environment Canada's Mete-
   orological Service of Canada
•  Michael Comba , Ed Sverko, and the  staff of the Organic Analysis Laboratory at En-
   vironment Canada's National Laboratory for Environmental Testing
•  Bruce Harrison and MaryLou Archer at the Ecosystem Health Division of Environ-
   ment Canada's Ontario Region
•  The staff at Philips Analytical
•  Peter Fowlie of Cornerstone Science

•  The U.S. EPA's Great Lakes National  Program Office, Serge LTtalien at Environment
   Canada's Ontario Region Ecosystem Health Division, Derek Muir and Bill Strachan
   at Environment Canada's National Water Research Institute, and Environment Can-
   ada's Meteorological Service of Canada for generous provision of lake water concen-
   tration data used in this report

-------
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                                       35

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Appendix A. Selected Data Used in Calculating IADN Loadings
                            36

-------
Table Al. Summary of meteorological data at IADN master stations, 1992-1998
_ake
Superior


Michigan


Huron


Erie


Ontario


Parameter
Annual Precipitation (mm)
Average Water Surface Temperature (K)
Average Wind Speed (m/s)
Annual Precipitation (mm)
Average Water Surface Temperature (K)
Average Wind Speed (m/s)
Annual Precipitation (mm)
Average Water Surface Temperature (K)
Average Wind Speed (m/s)
Annual Precipitation (mm)
Average Water Surface Temperature (K)
Average Wind Speed (m/s)
Annual Precipitation (mm)
Average Water Surface Temperature (K)
Average Wind Speed (m/s)
1992
665
278.4
3.02
866
280.0
2.88
1110
280.8
2.85
1073
283.6
2.85
1021
283.6
4.78
1993
990
278.4
3.09
1214
280.0
2.94
1110
280.8
3.50
1389
283.6
2.77
1021
283.6
4.98
1994
665
278.4
2.99
866
280.0
2.90
896
281.0
3.38
1073
283.6
2.63
837
283.6
4.66
1995
904
279.2
3.20
1182
282.5
3.04
931
281.8
3.69
933
284.3
2.99
816
284.3
4.71
1996
1148
277.7
2.84
1200
280.8
2.89
908
280.4
3.36
823
283.4
2.78
1000
283.4
4.51
1997
696
276.3
2.75
111
279.4
2.84
917
278.8
3.35
933
281.8
3.07
958
281.8
4.77
1998
1282
279.1
2.77
1793
281.9
2.83
810
280.8
3.20
1242
283.2
2.71
965
283.2
4.26
                                                37

-------
Table A2. Lake water concentrations for IADN 1997-1998 loadings calculations
Substance
ex-HCH
y-HCH
Dieldrin
c/s-chlordane
trans -chlordane
ex-endosulfan
p,p' -DDE
p,p' -DDT
p, p' -ODD
HCB
PCB18
PCB44
PCB52
PCB101
suite-PCB
Phenanthrene
Pyrene
B[/3+/t]F
BTalP
trans -nonachlor
l[1,2,3-cdlP
endosulfan sulfate
sum-PAH (UN ECE)
Lake Superior
Cone.
(ng/L)
2.04
0.439
0.145
0.0113
0.0200
0.00575
0.00285
0.00866
0.00021
0.00909
0.00150
0.00156
0.00138
0.00026
0.0471
0.568
0.175
0.0310
0.0331
0.00182
0.0494
-
0.113
n
94
111
89
94
94
64
69
65
47
70
b
5
5
5
b
27
27
13
27
66
28
-
-
cov
(%)
1
1
1
0
0
7
4
10
37
2
21
86
56
23
21
5
5
38
1
3
5
-
11
Source
1, 2, 3, 4, 5
1, 2, 3, 4, 5
1, 2, 4, 5
1, 2, 3, 4, 5
1, 2, 3, 4, 5
1, 4, 5
1, 3, 4, 5
1, 4, 5
3, 4, 5
1, 3, 4, 5
3
3
3
3
3
1
1
1
1
2, 3, 4, 5
1
-
1
Lake Michigan
Cone.
(ng/L)
0.398
0.119
-
0.00713
0.00466
-
0.0102
0.00359
0.00034
0.0101
0.00308
0.00427
0.000175
0.00264
0.0469
-
-
-
-
0.00562
-
-
-
n
5
5
-
5
5
-
5
5
5
5
b
5
5
5
b
-
-
-
-
5
-
-
-
COV
(%)
8
3
-
27
30
-
56
37
0
17
27
20
0
21
9
-
-
-
-
55
-
-
-
Source
3
3
-
3
3
-
3
3
3
3
3
3
3
3
3
-
-
-
-
3
-
-
-
Lake Huron
Cone.
(ng/L)
0.465
0.0923
-
0.00345
0.00144
-
0.00324
0.00209
0.000340
0.00816
0.00220
0.00167
0.000838
0.00118
0.0530
-
-
-
-
0.00242
-
-
-
n
5
5
-
5
5
-
5
5
5
5
b
5
5
5
b
-
-
-
-
5
-
-
-
COV
(%)
11
55
-
15
14
-
25
21
0
11
16
62
177
11
4
-
-
-
-
18
-
-
-
Source
3
3
-
3
3
-
3
3
3
3
3
3
3
3
3
-
-
-
-
3
-
-
-
Lake Erie
Cone.
(ng/L)
0.322
0.252
0.143
0.00934
0.0124
0.0187
0.0338
0.0667
-
0.0120
0.00816
0.00816
0.0001 75
0.00315
0.132
1.37
0.385
0.164
0.147
0.00348
0.144
-
0.456
n
46
46
3b
46
46
40
46
46
-
46
6
6
6
6
6
40
40
40
40
6
40
-
-
COV
(%)
3
3
8
6
4
4
2
0
-
6
48
70
0
87
14
6
16
11
5
37
15
-
6
Source
3, 6
3, 6
6
3, 6
3, 6
6
3, 6
3, 6
-
3, 6
3
3
3
3
3
6
6
6
6
3
6
-
6
Lake Ontario
Cone.
(ng/L)
0.449
0.232
0.141
0.00493
0.00262
0.0272
0.0222
0.00509
-
0.0115
0.00498
0.00466
0.00268
0.00203
0.0781
1.41
0.557
0.303
0.169
0.00302
-
-
-
n
50
50
2/
32
32
20
25
25
-
25
b
5
5
5
b
20
20
20
20
12
-
-
-
COV
(%)
6
6
6
8
6
64
14
13
-
4
40
55
209
22
11
20
20
20
20
22
-
-
-
Source
3, 6, 7
3, 6, 7
6, 7
3, 6, 7
3, 6, 7
6
3, 6
3, 6
-
3, 6
3
3
3
3
3
6
6
6
6
3, 7
-
-
-
Data Sources:
1. EHD cruise (CCGV Limnos) of spring and summer 1997 analyzed by NLET, under contract to Maxxam Analytics; 2. CCGVLimnos cruise of spring and
summer 1997 analyzed by MSC; 3. U.S. R/V Lake Guardian cruise of spring 1997 analyzed by U.S. EPA GLNPO; 4. CCGV Limnos cruise of spring and sum-
mer 1997 analyzed by NWRI; 5. CCGV Limnos cruise of spring 1998 analyzed by NWRI; 6. EHD cruises (CCGV Limnos) of spring 1998 on Lake Ontario and
spring and summer 1998 on Lake Erie analyzed by NLET, under contract to Maxxam Analytics; 7. CCGV Limnos cruise of spring 1998 analyzed by MSC
                                                                 38

-------
Table A3. IADN concentration data availability from 1992 to 1998 for all master
stations
         Agency
         Media
                   Substance
                                 Year
             1992 | 1993 |  1994 | 1995 | 1996 |  1997 | 1998
         EPA: Eagle Harbor, Sleeping Bear Dunes, Sturgeon Pt., NT-Chicago
         Gas
         PCBs     Eagle Harbor
                Sleeping Bear Dunes
                  Sturgeon Point
                    NT-Chicago
         Particle
         Precipitation
Pesticides
  PAHs

  PCBs
Pesticides
  PAHs
 metals

  PCBs
Pesticides
  PAHs
 metals
         MSC: Burnt Island, Pt. Petre
         Gas
         Particle
  PCBs
Pesticides
  PAHs

  PCBs
Pesticides
  PAHs
 metals
         EHD: Burnt Island, Pt. Petre
         Precipitation
                      PCBs
                    Pesticides
                      PAHs
                      metals
         NWRI: Burnt Island, Pt. Petre
         Precipitation
                      PCBs
                    Pesticides
                      metals
I       I      I      I
                                  All ov<~or>t HPR  RDF cin<~o 1QQR
                         I    J	I	I
                                           39

-------
Table A4. Lake water concentration availability for substances used in loadings
culations since 1992
cal-
                                                   Year
                         1992     1993    1994    1995    1996     1997    1998
     Water Concentration: Non-IADN Sources
     a-HCH, Y-HCH
               Superior
               Michigan
                Huron
                 Erie
     Dieldrin
               Superior
               Michigan
                Huron
                 Erie
     p,p ' -DDE
               Superior
               Michigan
                Huron
                 Erie
               Ontario
     p,p ' -DDT
               Superior
               Michigan
                Huron
                 Erie
               Ontario
               Superior
               Michigan
                Huron
                 Erie
               Ontario
     HCB and PCBs: 18, 44, 52,101, suite
               Superior
               Michigan
                Huron
                 Erie
               Ontario
     Phen, Pyr, B[k]F, B\b+k]F
               Superior
               Michigan
                Huron
                 Erie
               Ontario
     B[a]P
               Superior
               Michigan
                Huron
                 Erie
                                           40

-------
Table A5. Lake water concentration availability for additional substances added to
loadings calculations in 1995
            Additional
            Species
             Year
1995    1996     1997     1998
            Water Concentration: Non-IADN Sources
            oc-endosulfan
                      Superior
                      Michigan
                       Huron
                        Erie
                      Ontario
            c/s -chlordane, trans -chlordane
                      Superior
                      Michigan
                       Huron
                        Erie
                      Ontario
            trans -nonachlor
                      Superior
                      Michigan
                       Huron
                        Erie
                      Ontario
            Endosulfan Sulfate
                      Superior
                      Michigan
                       Huron
                        Erie
                       Ontario
            lndeno[1,2,3-cc/]pyrene
                      Superior
                      Michigan
                       Huron
                        Erie
                      Ontario
                                      41

-------
Appendix B. Annual IADN Fluxes (ng/m2/d) for 1997-1998
                           42

-------
Table Bl. Annual atmospheric fluxes to Lake Superior for 1997
Banned Or-
ganochlorine Pesti-
cides
a-HCH
dieldrin
czs-chlordane
trans-ch\ordane
trans-nonach\or
pp'-DDD
pp'-DDE
p,p'-DDT
In-Use Pesticides
y-HCH (lindane)
a-endosulfan
endosulfan sulfate
Banned O r-
ganocWorine
Commercial
Chemicals
HCB
PCB18
PCB44
PCB52
PCB 101
suite-PCB
PAHs and Metals
PHEN
PYR
B[b+k]F
B[a]P
I[l,2,3-cd\P
sum-PAH (UN ECE)
Pb
As
Se
Cd
Lake Superior 1997
Wet Deposition
Mean
n^m /d
1.2
0.59
0.13
0.038
0.042
0.011
0.085
0.13
cov
%
78
69
190
180
180
240
82
130
Dry Deposition
Mean
ng/m /d
0.097
0.51
0.083
0.054
0.049
0.037
-
0.047
COV
%
260
140
170
140
130
250
-
100
Gas Exchange
Gas Absorption
Mean
ng/m /d
19
1.4
0.48
0.51
0.11
0.2
0.35
0.29
COV
%
79
140
110
180
110
140
220
140
Volatilization
Mean
ng/m /d
-28
-8.7
-1
-2.2
-0.29
-0.0019
-0.29
-0.2
COV
%
50
50
50
50
50
62
50
51
Net Gas Exchange
Mean
ng/m2/d
-9.7
-7.2
-0.56
-1.7
-0.18
0.2
0.062
0.088
COV
%
150
59
120
77
100
140
980
340
Total Mass Flux
Mean
ng/m2/d
-8.4
-6.1
-0.35
-1.6
-0.089
0.25
0.15
0.27
COV
%
170
71
210
82
230
120
410
130

Wet Deposition
Mean
ng/m2/d
0.89
0.52
0.24
COV
%
140
87
100
Dry Deposition
Mean
ng/m2/d
0.14
0.97
0.11
COV
%
150
130
170
Gas Exchange
Gas Absorption
Mean
ng/m2/d
5.7
1.9
-
COV
%
140
210
-
Volatilization
Mean
ng/m2/d
-3.4
-0.89
-
COV
%
50
50
-
Net Gas Exchange
Mean
ng/m2/d
2.3
1
-
COV
%
280
320
-
Total Mass Flux
Mean
ng/m2/d
3.3
2.5
-
COV
%
200
140
-

Wet Deposition
Mean
ng/m2/d
0.034
0.078
0.089
0.1
0.1
2.5
COV
%
57
130
150
200
110
110
Dry Deposition
Mean
ng/m2/d
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
2.6
0.13
0.25
0.27
0.17
4.2
COV
%
66
100
130
110
120
110
Volatilization
Mean
ng/m2/d
-2
-0.3
-0.27
-0.22
-0.038
-11
COV
%
50
54
99
75
55
54
Net Gas Exchange
Mean
ng/m2/d
0.59
-0.17
-0.019
0.051
0.13
-7.1
COV
%
160
120
810
350
150
100
Total Mass Flux
Mean
ng/m2/d
0.62
-0.092
0.07
0.15
0.23
-4.6
COV
%
150
250
290
180
97
170

Wet Deposition
Mean
ng/m2/d
9.1
5.7
7.7
2.4
4.6
15
-
-
-
-
COV
%
180
140
140
87
160
91
-
-
-
-
Dry Deposition
Mean
ng/m2/d
3.2
2.5
5.6
1.3
2.5
9.4
-
-
-
-
COV
%
130
120
100
120
130
110
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
100
8.2
3.3
1.3
0.83
5.4
-
-
-
-
COV
%
96
120
67
59
60
44
-
-
-
-
Volatilization
Mean
ng/m2/d
-47
-6.2
-0.045
-0.13
-2.4E-05
-0.17
-
-
-
-
COV
%
50
50
63
50
50
40
-
-
-
-
Net Gas Exchange
Mean
ng/m2/d
55
2.1
3.3
1.2
0.83
5.3
-
-
-
-
COV
%
150
370
67
60
60
45
-
-
-
-
Total Mass Flux
Mean
ng/m2/d
67
10
17
4.9
7.9
30
-
-
-
-
COV
%
130
120
73
55
100
58
-
-
-
-
                                   43

-------
Table B2. Annual atmospheric fluxes to Lake Superior for 1998
Banned Or-
ganochlorine Pesti-
cides
a-HCH
dieldrin
czs-chlordane
trans-ch\ordane
trans-nonach\or
pp'-DDD
pp'-DDE
p,p'-DDT
In-Use Pesticides
y-HCH (lindane)
a-endosulfan
endosulfan sulfate
Banned Or-
ganochlorine
Commercial
Chemicals
HCB
PCB18
PCB44
PCB52
PCB 101
suite-PCB
PAHs and Metals
PHEN
PYR
B[b+k]F
B[a]P
I[l,2,3-c^P
sum-PAH (UN ECE)
Pb
As
Se
Cd
Lake Superior 1998
Wet Deposition
Mean
n^m2/d
0.22
0.38
0.092
0.024
0.019
0.025
0.077
0.13
cov
%
78
69
190
180
180
240
82
130
Dry Deposition
Mean
ng/m2/d
0.063
0.6
0.069
0.053
0.033
0.021
-
0.059
COV
%
250
120
120
120
130
110
-
140
Gas Exchange
Gas Absorption
Mean
ng/m /d
21
1
0.32
0.21
0.12
0.17
0.19
0.31
COV
%
98
140
91
110
95
120
91
140
Volatilization
Mean
ng/m /d
-37
-10
-1.2
-2.5
-0.31
-0.0026
-0.33
-0.26
COV
%
50
50
50
50
50
62
50
51
Net Gas Exchange
Mean
ng/m /d
-16
-9.5
-0.88
-2.3
-0.19
0.17
-0.13
0.049
COV
%
170
54
60
51
75
120
140
440
Total Mass Flux
Mean
ng/m2/d
-16
-8.5
-0.72
-2.2
-0.14
0.22
-0.053
0.24
COV
%
170
61
78
53
110
97
360
120

Wet Deposition
Mean
n^m2/d
0.34
0.16
0.12
COV
%
140
87
100
Dry Deposition
Mean
ng/m2/d
0.075
0.95
0.061
COV
%
130
110
150
Gas Exchange
Gas Absorption
Mean
ng/m2/d
4.2
1.5
-
COV
%
99
220
-
Volatilization
Mean
ng/m2/d
-4.3
-0.91
-
COV
%
50
50
-
Net Gas Exchange
Mean
ng/m2/d
-0.15
0.62
-
COV
%
1400
370
-
Total Mass Flux
Mean
ng/m2/d
0.27
1.7
-
COV
%
800
150
-

Wet Deposition
Mean
n^m2/d
0.02
0.038
0.18
0.055
0.12
2.3
COV
%
57
130
150
200
110
110
Dry Deposition
Mean
ng/m2/d
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
2.9
0.13
0.21
0.25
0.15
3.5
COV
%
63
93
110
98
97
96
Volatilization
Mean
ng/m2/d
-2.1
-0.31
-0.28
-0.23
-0.041
-11
COV
%
50
54
99
75
55
54
Net Gas Exchange
Mean
ng/m2/d
0.85
-0.18
-0.076
0.018
0.11
-7.8
COV
%
160
89
500
480
120
74
Total Mass Flux
Mean
ng/m2/d
0.87
-0.14
0.1
0.073
0.23
-5.5
COV
%
160
120
470
190
81
110

Wet Deposition
Mean
n^m2/d
3.7
2.8
4.9
1.6
2.4
8.9
-
-
-
-
COV
%
180
140
140
87
160
91
-
-
-
-
Dry Deposition
Mean
ng/m2/d
2.5
2.4
4.8
1.2
2.1
8.2
-
-
-
-
COV
%
120
140
110
150
150
110
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m /d
81
8.2
3.4
1.3
0.8
5.5
-
-
-
-
COV
%
93
130
87
60
60
58
-
-
-
-
Volatilization
Mean
ng/m /d
-54
-7.2
-0.063
-0.17
-3.3E-05
-0.24
-
-
-
-
COV
%
50
50
63
50
50
40
-
-
-
-
Net Gas Exchange
Mean
ng/m /d
28
0.94
3.4
1.1
0.8
5.3
-
-
-
-
COV
%
200
560
88
63
60
59
-
-
-
-
Total Mass Flux
Mean
ng/m2/d
34
6.1
13
3.9
5.3
22
-
-
-
-
COV
%
170
120
70
61
94
57
-
-
-
-
                                   44

-------
Table B3. Annual atmospheric fluxes to Lake Michigan for 1997
Banned Or-
ganochlorine Pes-
ticides
a-HCH
dieldrin
czs-chlordane
fra«*-chlordane
frans-nonachlor
pp'-DDD
pp'-DDE
pp'-DDT
In-Use Pesticides
y-HCH (lindane)
a-endosulfan
endosulfan sulfate
Banned O r-
ganochlorine
Commercial
Chemicals
HCB
PCB18
PCB44
PCB52
PCB 101
suite-PCB
PAHs and Metals
PHEN
PYR
B[b+k]F
B[a]P
I[l,2,3-a/]P
sum-PAH (UN ECE)
Pb
As
Se
Cd
Lake Michigan 1997
Wet Deposition
Mean
ng/m2/d
1.9
1.2
0.47
0.052
0.037
0.017
0.12
0.2
cov
%
260
120
190
130
130
110
79
220
Dry Deposition
Mean
ng/m2/d
0.16
0.73
0.12
0.069
0.054
0.036
-
0.052
COV
%
410
140
180
140
130
130
-
110
Gas Exchange
Gas Absorption
Mean
ng/m2/d
22
3.4
0.85
0.56
0.19
0.17
1.1
0.73
COV
%
110
100
90
94
110
150
99
120
Volatilization
Mean
ng/m2/d
-7.3
-
-0.75
-0.58
-0.97
-0.0044
-1.2
-0.11
COV
%
51
-
57
59
74
50
75
62
Net Gas Exchange
Mean
ng/m2/d
14
-
0.1
-0.017
-0.77
0.17
-0.073
0.62
COV
%
150
-
170
200
110
150
270
130
Total Mass Flux
Mean
ng/m2/d
16
-
0.69
0.1
-0.68
0.22
0.047
0.87
COV
%
130
-
140
120
130
120
470
110

Wet Deposition
Mean
ng/m2/d
1.5
0.69
0.44
COV
%
290
230
300
Dry Deposition
Mean
ng/m2/d
0.11
1.7
0.2
COV
%
150
200
160
Gas Exchange
Gas Absorption
Mean
ng/m2/d
8.4
39
-
COV
%
110
170
-
Volatilization
Mean
ng/m2/d
-1.2
-
-
COV
%
50
-
-
Net Gas Exchange
Mean
ng/m2/d
7.2
-
-
COV
%
120
-
-
Total Mass Flux
Mean
ng/m2/d
0 0
o.o
-
-
COV
%
110
-
-

Wet Deposition
Mean
ng/m /d
0.035
0.039
0.062
0.079
0.051
1.2
COV
%
48
65
75
55
93
44
Dry Deposition
Mean
ng/m2/d
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
3.1
0.32
0.31
0.48
0.20
6.2
COV
%
64
120
110
110
100
120
Volatilization
Mean
ng/m2/d
-2.3
-0.65
-0.78
-0.03
-0.42
-8.8
COV
%
53
57
54
50
54
51
Net Gas Exchange
Mean
ng/m2/d
0.74
-0.39
-0.52
0.45
-0.24
-3.2
COV
%
160
100
68
120
79
170
Total Mass Flux
Mean
ng/m2/d
0.78
-0.35
-0.46
0.53
-0.19
_9
COV
%
150
110
78
100
100
280

Wet Deposition
Mean
ng/m2/d
15
11
16
5.7
9.4
31
-
-
-
-
COV
%
340
340
140
160
160
91
-
-
-
-
Dry Deposition
Mean
ng/m2/d
4.6
4.7
8.7
2.3
4
15
-
-
-
-
COV
%
130
140
120
140
150
120
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
160
15
4.4
1.4
1.3
7.2
-
-
-
-
COV
%
81
84
66
62
75
45
-
-
-
-
Volatilization
Mean
ng/m2/d
-
-
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
-
-
Net Gas Exchange
Mean
ng/m2/d
-
-
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
-
-
Total Mass Flux
Mean
ng/m2/d
-
-
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
-
-
                                   45

-------
Table B4. Annual atmospheric fluxes to Lake Michigan for 1998
Banned Or-
ganochlorine Pes-
ticides
a-HCH
dieldrin
czs-chlordane
trans-ch\ordane
trans-nonachlor
pp'-DDD
p,p'-DDE
p,p'-DDT
In-Use Pesticides
y-HCH (lindane)
a-endosulfan
endosulfan sulfate
Banned O r-
ganochlorine
Commercial
Chemicals
HCB
PCB18
PCB44
PCB52
PCB 101
suite-PCB
PAHs and Metals
PHEN
PYR
B[b+k]F
B[a]P
I[l,2,3-a/]P
sum-PAH (UN ECE)
Pb
As
Se
Cd
Lake Michigan 1998
Wet Deposition
Mean
ng/m /d
0.8
1.5
0.52
0.058
0.042
0.14
0.13
0.14
cov
%
260
120
190
130
130
110
79
220
Dry Deposition
Mean
ng/m2/d
0.043
0.87
0.15
0.085
0.039
0.047
-
0.093
COV
%
150
120
160
120
130
130
-
260
Gas Exchange
Gas Absorption
Mean
ng/m2/d
18
2.1
0.61
0.4
0.2
0.26
0.7
0.79
COV
%
110
140
99
110
100
140
110
170
Volatilization
Mean
ng/m2/d
-8.8
-
-0.82
-0.63
-0.99
-0.0055
-1.3
-0.13
COV
%
51
-
57
59
74
50
75
62
Net Gas Exchange
Mean
ng/m2/d
9.7
-
-0.21
-0.23
-0.79
0.25
-0.57
0.66
COV
%
170
-
500
300
90
150
320
190
Total Mass Flux
Mean
n^m /d
11
-
0.46
-0.087
-0.71
0.44
-0.44
0.89
COV
%
150
-
320
810
100
93
420
150

Wet Deposition
Mean
ng/m2/d
0.61
0.49
0.42
COV
%
290
230
300
Dry Deposition
Mean
ng/m2/d
0.089
6.6
0.17
COV
%
220
310
160
Gas Exchange
Gas Absorption
Mean
ng/m2/d
10
40
-
COV
%
160
170
-
Volatilization
Mean
ng/m2/d
-1.4
-
-
COV
%
50
-
-
Net Gas Exchange
Mean
ng/m2/d
8.9
-
-
COV
%
180
-
-
Total Mass Flux
Mean
ng/m2/d
9.6
-
-
COV
%
170
-
-

Wet Deposition
Mean
ng/m2/d
0.039
0.065
0.13
0.091
0.082
1.8
COV
%
48
65
75
55
93
44
Dry Deposition
Mean
ng/m2/d
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
3.6
0.40
0.28
0.55
0.24
7.4
COV
%
67
96
120
98
110
100
Volatilization
Mean
ng/m2/d
-2.3
-0.66
-0.8
-0.031
-0.44
-9
COV
%
53
57
54
50
54
51
Net Gas Exchange
Mean
ng/m2/d
1.2
-0.26
-0.52
0.52
-0.20
-1.6
COV
%
180
240
130
100
230
2600
Total Mass Flux
Mean
ng/m2/d
1.2
-0.2
-0.39
0.61
-0.12
0.2
COV
%
180
310
180
86
390
21000

Wet Deposition
Mean
ng/m /d
8.5
6.4
13
4.2
6.6
24
-
-
-
-
COV
%
340
340
150
160
160
94
-
-
-
-
Dry Deposition
Mean
ng/m2/d
5.8
7.1
14
4.1
8.4
26
-
-
-
-
COV
%
130
170
140
210
210
130
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
130
19
5.3
1.5
1.8
8.5
-
-
-
-
COV
%
77
110
93
100
170
69
-
-
-
-
Volatilization
Mean
ng/m2/d
-
-
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
-
-
Net Gas Exchange
Mean
ng/m2/d
-
-
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
-
-
Total Mass Flux
Mean
n^m /d
-
-
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
-
-
                                   46

-------
Table B5. Annual atmospheric fluxes to Lake Huron for 1997
Banned Or-
ganochlorine Pes-
ticides
a-HCH
dieldrin
czs-chlordane
fra«*-chlordane
frans-nonachlor
pp'-DDD
pp'-DDE
pp'-DDT
In-Use Pesticides
y-HCH (lindane)
a-endosulfan
endosulfan sulfate
Banned O r-
ganochlorine
Commercial
Chemicals
HCB
PCB18
PCB44
PCB52
PCB 101
suite-PCB
PAHs and Metals
PHEN
PYR
B[b+k]F
B[a]P
I[l,2,3-a/]P
sum-PAH (UN ECE)
Pb
As
Se
Cd
Lake Huron 1997
Wet Deposition
Mean
ng/m2/d
3.3
1.2
0.17
0.21
-
1.2
0.97
2.1
cov
%
240
160
-
-
-
960
1900
2500
Dry Deposition
Mean
ng/m2/d
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
8.3
1.4
0.27
0.19
0.12
0.046
0.21
0.33
COV
%
68
110
110
110
110
91
110
100
Volatilization
Mean
ng/m2/d
-9
-
-0.43
-0.22
-0.57
-0.0046
-0.44
-0.068
COV
%
51
-
52
52
53
50
56
54
Net Gas Exchange
Mean
ng/m2/d
-0.67
-
-0.16
-0.032
-0.45
0.042
-0.23
0.26
COV
%
3000
-
510
680
110
98
280
120
Total Mass Flux
Mean
ng/m2/d
2.6
-
0.01
0.18
-
1.2
0.74
2.4
COV
%
830
-
-
-
-
960
2500
2200

Wet Deposition
Mean
ng/m2/d
4.8
1.3
-
COV
%
160
230
-
Dry Deposition
Mean
ng/m2/d
-
-
-
COV
%
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
3.5
5.1
-
COV
%
110
150
-
Volatilization
Mean
ng/m2/d
-0.98
-
-
COV
%
74
-
-
Net Gas Exchange
Mean
ng/m2/d
2.6
-
-
COV
%
150
-
-
Total Mass Flux
Mean
ng/m2/d
7.4
-
-
COV
%
120
-
-

Wet Deposition
Mean
ng/m /d
0.17
-
-
-
-
-
COV
%
490
-
-
-
-
-
Dry Deposition
Mean
ng/m2/d
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
9
0.64
0.12
0.28
0.12
3.1
COV
%
63
82
97
90
94
87
Volatilization
Mean
ng/m2/d
-2.7
-0.65
-0.41
-0.18
-0.24
-13
COV
%
51
53
79
180
51
50
Net Gas Exchange
Mean
ng/m2/d
-0.73
-0.0085
-0.29
0.092
-0.13
-10
COV
%
150
710
150
280
170
80
Total Mass Flux
Mean
ng/m2/d
-0.56
-0.0085
-0.29
0.092
-0.13
-10
COV
%
250
710
150
280
170
80

Wet Deposition
Mean
ng/m2/d
35
31
28
13
20
61
2800
-
-
130
COV
%
290
290
-
-
1500
-
1600
-
-
1900
Dry Deposition
Mean
ng/m2/d
6.6
7.1
9.8
3.9
6.4
20
570
70
27
22
COV
%
170
160
110
160
140
110
150
140
230
170
Gas Exchange
Gas Absorption
Mean
ng/m2/d
64
10
1.5
0.28
1.7
3.4
-
-
-
-
COV
%
84
120
100
60
59
53
-
-
-
-
Volatilization
Mean
ng/m2/d
-
-
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
-
-
Net Gas Exchange
Mean
ng/m2/d
-
-
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
-
-
Total Mass Flux
Mean
ng/m2/d
-
-
-
-
-
-
3400
-
-
150
COV
%
-
-
-
-
-
-
1300
-
-
1600
                                  47

-------
Table B6. Annual atmospheric fluxes to Lake Huron for 1998
Banned Or-
ganochlorine Pes-
ticides
a-HCH
dieldrin
czs-chlordane
fra«*-chlordane
frans-nonachlor
pp'-DDD
pp'-DDE
pp'-DDT
In-Use Pesticides
y-HCH (lindane)
a-endosulfan
endosulfan sulfate
Banned O r-
ganochlorine
Commercial
Chemicals
HCB
PCB18
PCB44
PCB52
PCB 101
suite-PCB
PAHs and Metals
PHEN
PYR
B[b+k]F
B[a]P
I[l,2,3-a/]P
sum-PAH (UN ECE)
Pb
As
Se
Cd
Lake Huron 1998
Wet Deposition
Mean
ng/m2/d
1.8
0.78
0.077
0.16
0.018
0.28
0.27
0.13
cov
%
240
160
-
-
-
960
1900
2500
Dry Deposition
Mean
ng/m2/d
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
6.8
1.4
0.28
0.19
0.11
0.042
0.26
0.27
COV
%
67
110
100
97
100
120
98
160
Volatilization
Mean
ng/m2/d
-11
-
-0.48
-0.24
-0.55
-0.0056
-0.49
-0.081
COV
%
51
-
52
52
53
50
56
54
Net Gas Exchange
Mean
ng/m2/d
-3.8
-
-0.19
-0.051
-0.45
0.036
-0.23
0.19
COV
%
220
-
260
460
99
130
210
210
Total Mass Flux
Mean
n^m2/d
-2
-
-0.11
0.11
-0.43
0.32
0.04
0.32
COV
%
470
-
-
-
-
840
13000
1000

Wet Deposition
Mean
ng/m2/d
5.8
1.5
-
COV
%
160
230
-
Dry Deposition
Mean
ng/m2/d
-
-
-
COV
%
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
2.8
4.8
-
COV
%
120
140
-
Volatilization
Mean
ng/m2/d
-1.1
-
-
COV
%
74
-
-
Net Gas Exchange
Mean
ng/m2/d
1.7
-
-
COV
%
180
-
-
Total Mass Flux
Mean
ngW/d
7.5
-
-
COV
%
130
-
-

Wet Deposition
Mean
ng/m /d
0.043
-
-
-
-
-
COV
%
490
-
-
-
-
-
Dry Deposiion
Mean
ng/m2/d
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
1.7
0.38
0.095
0.22
0.09
1.9
COV
%
67
71
76
78
85
76
Volatilization
Mean
ng/m2/d
-2.5
-0.6
-0.4
-0.18
-0.25
-13
COV
%
51
53
79
180
51
50
Net Gas Exchange
Mean
ng/m2/d
-0.8
-0.22
-0.3
0.033
-0.16
-11
COV
%
150
180
130
910
110
73
Total Mass Flux
Mean
n^m /d
-0.76
-0.22
-0.3
0.033
-0.16
-11
COV
%
160
180
130
910
110
73

Wet Deposition
Mean
ng/m2/d
33
17
19
9.6
16
45
1300
-
-
190
COV
%
290
290
-
-
1500
-
1600
-
-
1900
Dry Deposition
Mean
ng/m2/d
2.7
4.3
7.2
2.6
4.7
14
330
55
26
13
COV
%
150
150
130
150
170
120
150
170
210
160
Gas Exchange
Gas Absorption
Mean
ng/m2/d
46
10
1.3
0.4
2.1
3.8
-
-
-
-
COV
%
70
80
63
59
59
40
-
-
-
-
Volatilization
Mean
ng/m2/d
-
-
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
-
-
Net Gas Exchange
Mean
ng/m2/d
-
-
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
-
-
Total Mass Flux
Mean
ng/m2/d
-
-
-
-
-
-
1600
-
-
200
COV
%
-
-
-
-
-
-
1300
-
-
1800
                                  48

-------
Table B7. Annual atmospheric fluxes to Lake Erie for 1997
Banned Or-
ganochlorine Pesti-
cides
a-HCH
dieldrin
czs-chlordane
fra«*-chlordane
frans-nonachlor
pp'-DDD
pp'-DDE
pp'-DDT
In-Use Pesticides
y-HCH (lindane)
a-endosulfan
endosulfan sulfate
Banned O r-
ganochlorine
Commercial
Chemicals
HCB
PCB18
PCB44
PCB52
PCB 101
suite-PCB
PAHs and Metals
PHEN
PYR
B[b+k]F
B[a]P
I[l,2,3-a/]P
sum-PAH (UN ECE)
Pb
As
Se
Cd
Lake Erie 1997
Wet Deposition
Mean
n^m2/d
0.58
0.98
1.3
0.08
0.053
0.079
0.2
0.24
cov
%
130
120
130
120
93
330
160
150
Dry Deposition
Mean
n^m2/d
0.026
0.9
0.28
0.12
0.083
0.077
-
0.13
COV
%
130
120
120
130
130
190
-
160
Gas Exchange
Gas Absorption
Mean
ng/m2/d
16
3.2
1.1
0.86
0.25
0.37
1.6
1.4
COV
%
79
140
98
100
110
170
100
110
Volatilization
Mean
ng/m2/d
-7.1
-12
-1.1
-1.8
-0.68
-
-4.3
-2.4
COV
%
50
51
50
50
62
-
50
50
Net Gas Exchange
Mean
ng/m2/d
8.7
-8.7
0.035
-0.89
-0.43
-
-2.7
-1.1
COV
%
120
130
490
180
170
-
110
180
Total Mass Flux
Mean
ng/m2/d
9.3
-6.8
1.6
-0.69
-0.29
-
-2.5
-0.73
COV
%
110
170
110
230
260
-
120
280

Wet Deposition
Mean
ngW/d
0.56
0.48
-
COV
%
140
180
-
Dry Deposition
Mean
n^m2/d
0.14
1.3
0.23
COV
%
170
120
160
Gas Exchange
Gas Absorption
Mean
ng/m2/d
7.5
31
-
COV
%
130
160
-
Volatilization
Mean
ng/m2/d
-3
-0.0047
-
COV
%
50
50
-
Net Gas Exchange
Mean
ng/m2/d
4.4
31
-
COV
%
200
160
-
Total Mass Flux
Mean
ng/m2/d
5.1
33
-
COV
%
170
150
-

Wet Deposition
Mean
n^m /d
0.032
0.037
0.045
0.064
0.057
1.4
COV
%
150
130
190
150
140
140
Dry Deposition
Mean
n^m2/d
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
2.8
0.51
1.3
1
0.45
11
COV
%
66
100
150
110
120
110
Volatilization
Mean
ng/m2/d
-3.1
-1.9
-1.7
-0.033
-0.56
-28
COV
%
50
70
86
50
100
52
Net Gas Exchange
Mean
ng/m2/d
-0.29
-1.4
-0.37
0.96
-0.12
-17
COV
%
460
130
600
120
3200
140
Total Mass Flux
Mean
ng/m2/d
-0.26
-1.4
-0.33
1
-0.063
-16
COV
%
510
130
670
120
6100
150

Wet Deposition
Mean
ng/m2/d
31
23
33
13
16
62
-
-
-
-
COV
%
210
210
120
110
120
78
-
-
-
-
Dry Deposition
Mean
ng/m2/d
17
19
40
11
19
70
-
-
-
-
COV
%
120
130
97
130
130
110
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
530
57
4.4
1.6
1
7
-
-
-
-
COV
%
99
110
67
68
67
46
-
-
-
-
Volatilization
Mean
ng/m2/d
-140
-18
-0.44
-1
-0.00013
-1.5
-
-
-
-
COV
%
50
52
51
50
52
38
-
-
-
-
Net Gas Exchange
Mean
ng/m2/d
390
39
3.9
0.54
1
5.5
-
-
-
-
COV
%
130
180
70
140
68
53
-
-
-
-
Total Mass Flux
Mean
ng/m2/d
440
81
77
25
36
140
-
-
-
-
COV
%
120
110
72
81
87
65
-
-
-
-
                                   49

-------
Table B8. Annual atmospheric fluxes to Lake Erie for 1998
Banned Or-
ganochlorine Pesti-
cides
a-HCH
dieldrin
czs-chlordane
fra«*-chlordane
frans-nonachlor
pp'-DDD
pp'-DDE
pp'-DDT
In-Use Pesticides
y-HCH (lindane)
a-endosulfan
endosulfan sulfate
Banned O r-
ganochlorine
Commercial
Chemicals
HCB
PCB18
PCB44
PCB52
PCB 101
suite-PCB
PAHs and Metals
PHEN
PYR
B[b+k]F
B[a]P
I[l,2,3-a/]P
sum-PAH (UN ECE)
Pb
As
Se
Cd
Lake Erie 1998
Wet Deposition
Mean
n^m2/d
0.16
0.26
0.15
0.014
0.011
0.077
0.04
0.04
cov
%
130
120
130
120
93
330
160
150
Dry Deposition
Mean
n^m2/d
0.021
0.82
0.39
0.11
0.035
0.084
-
0.068
COV
%
250
130
150
130
130
140
-
180
Gas Exchange
Gas Absorption
Mean
ng/m2/d
17
2.7
0.9
0.74
0.19
0.47
1.2
1.2
COV
%
110
170
120
110
120
160
120
160
Volatilization
Mean
ng/hi2/d
-7.4
-11
-0.99
-1.5
-0.54
-
-3.9
-2.5
COV
%
50
51
50
50
62
-
50
50
Net Gas Exchange
Mean
ng/m2/d
9.9
-8.6
-0.089
-0.77
-0.35
-
-2.7
-1.3
COV
%
160
130
1600
130
160
-
100
260

Wet Deposition
Mean
ngW/d
0.054
0.065
-
COV
%
140
180
-
Dry Deposition
Mean
n^m2/d
0.054
2.1
0.14
COV
%
160
200
170
Gas Exchange
Gas Absorption
Mean
ng/m2/d
7.2
27
-
COV
%
120
180
-
Volatilization
Mean
ng/m2/d
-3.1
-0.0045
-
COV
%
50
50
-
Net Gas Exchange
Mean
ng/m2/d
4.1
27
-
COV
%
190
180
-

Wet Deposition
Mean
n^m /d
0.024
0.011
0.039
0.023
0.026
0.49
COV
%
150
130
190
150
140
140
Dry Deposition
Mean
n^m2/d
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
2.3
0.43
0.68
0.84
0.39
9.5
COV
%
68
110
150
110
110
110
Volatilization
Mean
ng/m /d
-2.4
-1.5
-1.4
-0.027
-0.47
-22
COV
%
50
70
86
50
100
52
Net Gas Exchange
Mean
ng/m2/d
-0.1
-1.1
-0.67
0.81
-0.079
-13
COV
%
310
150
370
110
2300
180

Wet Deposition
Mean
ng/m2/d
9.5
5.3
10
2.9
3.1
16
-
-
-
-
COV
%
210
210
130
110
120
82
-
-
-
-
Dry Deposition
Mean
ng/m2/d
14
18
47
10
21
79
-
-
-
-
COV
%
130
130
120
130
140
120
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
520
54
4.6
1.4
0.94
7
-
-
-
-
COV
%
90
120
74
75
81
53
-
-
-
-
Volatilization
Mean
ng/m2/d
-130
-18
-0.48
-1.1
-0.00014
-1.6
-
-
-
-
COV
%
50
52
51
50
52
38
-
-
-
-
Net Gas Exchange
Mean
ng/m2/d
390
37
4.1
0.36
0.94
5.4
-
-
-
-
COV
%
120
180
78
200
81
63
-
-
-
-
Total Mass Flux
Mean
ng/m2/d
10
-7.5
0.45
-0.65
-0.3
-
-2.7
-1.2
COV
%
160
150
340
160
190
-
100
280

Total Mass Flux
Mean
ng/m2/d
4.2
29
-
COV
%
190
170
-

Total Mass Flux
Mean
ng/m2/d
-0.076
-1.1
-0.63
0.83
-0.053
-13
COV
%
410
150
390
110
3400
180

Total Mass Flux
Mean
ng/m2/d
410
60
61
13
25
100
-
-
-
-
COV
%
110
120
95
100
120
96
-
-
-
-
                                   50

-------
Table B9. Annual atmospheric fluxes to Lake Ontario for 1997
Banned Or-
ganochlorine Pesti-
cides
a-HCH
dieldrin
czs-chlordane
fra«*-chlordane
frans-nonachlor
pp'-DDD
pp'-DDE
pp'-DDT
In-Use Pesticides
y-HCH (lindane)
a-endosulfan
endosulfan sulfate
Banned O r-
ganochlorine
Commercial
Chemicals
HCB
PCB18
PCB44
PCB52
PCB 101
suite-PCB
PAHs and Metals
PHEN
PYR
B[b+k]F
B[a]P
l[l,2,3-cd\P
sum-PAH (UN ECE)
Pb
As
Se
Cd
Lake Ontario 1997
Wet Deposition
Mean
ng/m2/d
3.6
0.87
0.12
0.16
-
0.33
1.6
1.9
cov
%
55
74
64
72
-
53
67
91
Dry Deposition
Mean
n^m2/d
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
10
3.1
0.71
0.6
0.32
0.13
2
1.1
COV
%
68
130
110
110
120
110
140
140
Volatilization
Mean
ng/m2/d
-13
-19
-1
-0.68
-1.3
-
-5
-0.25
COV
%
50
50
51
50
55
-
52
52
Net Gas Exchange
Mean
ng/m2/d
-2.6
-15
-0.31
-0.074
-0.93
-
-3
0.83
COV
%
430
88
740
2800
130
-
220
170
Total Mass Flux
Mean
n^m2/d
1
-14
-0.19
0.086
-
-
-1.4
2.7
COV
%
1100
94
1200
2400
-
-
480
83

Wet Deposition
Mean
ng/m2/d
7.2
2
-
COV
%
63
220
-
Dry Deposition
Mean
n^m2/d
-
-
-
COV
%
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
4.6
26
-
COV
%
120
200
-
Volatilization
Mean
ng/m2/d
-3.6
-0.0095
-
COV
%
50
81
-
Net Gas Exchange
Mean
ng/m2/d
0.99
26
-
COV
%
360
200
-
Total Mass Flux
Mean
ngW/d
8.2
28
-
COV
%
70
190
-

Wet Deposition
Mean
ng/m2/d
0.13
-
-
-
-
-
COV
%
130
-
-
-
-
-
Dry Deposition
Mean
n^m2/d
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m /d
3.3
1.3
0.49
0.97
0.37
7.2
COV
%
64
95
100
96
100
95
Volatilization
Mean
ng/m2/d
-6.7
-2.6
-2
-1
-0.72
-34
COV
%
50
64
74
210
55
51
Net Gas Exchange
Mean
ng/m /d
-3.4
-1.3
-1.5
-0.029
-0.34
-27
COV
%
93
170
130
21000
240
91
Total Mass Flux
Mean
n^m /d
-3.3
-1.3
-1.5
-0.029
-0.34
-27
COV
%
96
170
130
21000
240
91

Wet Deposition
Mean
ng/m2/d
57
64
31
12
21
63
3000
-
-
150
COV
%
140
170
180
230
260
130
210
-
-
110
Dry Deposition
Mean
ng/m2/d
7.3
10
32
8.6
17
57
730
94
87
24
COV
%
120
130
100
130
130
110
140
200
140
110
Gas Exchange
Gas Absorption
Mean
ng/m2/d
150
21
1.5
0.32
2
3.8
-
-
-
-
COV
%
82
80
59
59
59
39
-
-
-
-
Volatilization
Mean
ng/m2/d
-240
-38
-0.98
-1.4
-
-
-
-
-
-
COV
%
80
88
100
65
-
-
-
-
-
-
Net Gas Exchange
Mean
ng/m2/d
-91
-16
0.51
-1.1
-
-
-
-
-
-
COV
%
260
270
190
120
-
-
-
-
-
-
Total Mass Flux
Mean
ng/m2/d
-27
58
64
20
-
-
3700
-
-
170
COV
%
930
200
100
150
-
-
170
-
-
98
                                   51

-------
Table BIO. Annual atmospheric fluxes to Lake Ontario for 1998
Banned Or-
ganochlorine Pesti-
cides
a-HCH
dieldrin
czs-chlordane
fra«*-chlordane
frans-nonachlor
pp'-DDD
pp'-DDE
pp'-DDT
In-Use Pesticides
y-HCH (lindane)
a-endosulfan
endosulfan sulfate
Banned O r-
ganochlorine
Commercial
Chemicals
HCB
PCB18
PCB44
PCB52
PCB 101
suite-PCB
PAHs and Metals
PHEN
PYR
B[b+k]F
B[a]P
l[l,2,3-cd\P
sum-PAH (UN ECE)
Pb
As
Se
Cd
Lake Ontario 1998
Wet Deposition
Mean
n^m2/d
3.1
0.65
0.13
0.12
0.045
0.29
0.56
0.18
cov
%
55
74
64
72
-
53
67
91
Dry Deposition
Mean
ng/m2/d
-
-
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
7.6
2.3
0.54
0.38
0.21
0.095
1.5
0.84
COV
%
70
120
120
110
110
110
120
130
Volatilization
Mean
ng/m2/d
-14
-20
-1
-0.67
-1.1
-
-5.1
-0.28
COV
%
50
50
51
50
55
-
52
52
Net Gas Exchange
Mean
ng/m2/d
-6.4
-17
-0.49
-0.29
-0.93
-
-3.5
0.56
COV
%
150
80
240
240
100
-
130
170
Total Mass Flux
Mean
ng/m2/d
-3.3
-16
-0.36
-0.17
-0.89
-
-2.9
0.74
COV
%
300
85
330
410
-
-
160
130

Wet Deposition
Mean
ngW/d
4.8
4
-
COV
%
63
220
-
Dry Deposition
Mean
ng/m2/d
-
-
-
COV
%
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
4.3
30
-
COV
%
130
220
-
Volatilization
Mean
ng/m2/d
-3.8
-0.0091
-
COV
%
50
81
-
Net Gas Exchange
Mean
ng/m2/d
0.49
30
-
COV
%
620
220
-
Total Mass Flux
Mean
ng/m2/d
5.3
34
-
COV
%
81
200
-

Wet Deposition
Mean
n^m /d
0.08
-
-
-
-
-
COV
%
130
-
-
-
-
-
Dry Deposition
Mean
ng/m /d
-
-
-
-
-
-
COV
%
-
-
-
-
-
-
Gas Exchange
Gas Absorption
Mean
ng/m2/d
2.6
0.75
0.3
0.62
0.26
4.6
COV
%
69
72
91
84
92
81
Volatilization
Mean
ng/m /d
-5.8
-2.2
-1.8
-0.92
-0.68
-31
COV
%
50
64
74
210
55
51
Net Gas Exchange
Mean
ng/m2/d
-3.2
-1.5
-1.5
-0.3
-0.41
-26
COV
%
90
130
120
470
140
86
Total Mass Flux
Mean
ng/m2/d
-3.1
-1.5
-1.5
-0.3
-0.41
-26
COV
%
93
130
120
470
140
86

Wet Deposition
Mean
ng/m2/d
49
31
37
11
14
62
5400
-
-
230
COV
%
140
170
190
230
260
130
210
-
-
110
Dry Deposition
Mean
ng/m2/d
7.5
15
46
9.9
21
76
840
150
67
24
COV
%
160
180
220
190
190
170
110
130
160
140
Gas Exchange
Gas Absorption
Mean
ng/m2/d
180
39
7.1
0.43
1.8
9.3
-
-
-
-
COV
%
91
130
230
80
59
170
-
-
-
-
Volatilization
Mean
ng/m2/d
-240
-39
-1.1
-1.6
-
-
-
-
-
-
COV
%
80
88
100
65
-
-
-
-
-
-
Net Gas Exchange
Mean
ng/m2/d
-59
0.52
6
-1.2
-
-
-
-
-
-
COV
%
330
2500
270
130
-
-
-
-
-
-
Total Mass Flux
Mean
ng/m2/d
-2.5
47
89
20
-
-
6200
-
-
250
COV
%
8300
130
140
160
-
-
180
-
-
100
                                   52

-------
Appendix C. Relative Loadings of IADN Substances, 1997-1998
                           53

-------
                                                    Lake Superior 1997
      -400
                              D Volatilization D Gas Absorption D Wet Deposition B Dry Deposition
Figure Cl. Loadings as a proportion of total deposition to Lake Superior for 1997. * indicates substances for which no vola-
tilization estimates could be made because of lack of water concentration data.  Refer to Table A3 for missing air concentra-
tion data.
                                                           54

-------
                                                     Lake Superior 1998
       100
       -50 -'
      -loo -•
      -150 -'
      -200 ''
       -525%

      -250 ' •
      -300
                              D Volatilization D Gas Absorption D Wet Deposition II Dry Deposition
Figure C2. Loadings as a proportion of total deposition to Lake Superior for 1998.  * indicates substances for which no vola-
tilization estimates could be made because of lack of water concentration data. Refer to Table A3 for missing air concentra-
tion data.
                                                            55

-------
                                                     Lake Michigan 1997
      -100 -•
      -150 -•


      -200 ''


      -250 - •


      -300 - •


      -350 - •
      -400
            ffi
            ffi
Q
Q
               m
               u
a>   B-   ^   PJ
£   ?  s   ?
                              D Volatilization D Gas Absorption D Wet Deposition II Dry Deposition
Figure C3. Loadings as a proportion of total deposition to Lake Michigan for 1997. * indicates substances for which no vola-
tilization estimates could be made because of lack of water concentration data. Refer to Table A3 for missing air concentra-
tion data.
                                                            56

-------
                                                    Lake Michigan 1998
       100
      -300
                              D Volatilization D Gas Absorption D Wet Deposition II Dry Deposition
Figure C4. Loadings as a proportion of total deposition to Lake Michigan for 1998.  * indicates substances for which no vola-
tilization estimates could be made because of lack of water concentration data.  Refer to Table A3 for missing air concentra-
tion data.
                                                           57

-------
                                                     Lake Huron 1997
       100
      -500
                             D Volatilization D Gas Absorption D Wet Deposition II Dry Deposition
Figure C5. Loadings as a proportion of total deposition to Lake Huron for 1997.  * indicates substances for which no volatili-
zation estimates could be made because of lack of water concentration data. Refer to Table A3 for missing air concentration
data.
                                                          58

-------
                                                      Lake Huron 1998
       100
       50
       -50 -'
      -loo -•
      -150 -•


      -200 ''


      -250 '•
      -300
            ffi
            ffi
-444% •
                                    4-	4	4-1	M	^
                                              *   *
-414%-
            §

                                   pq   oo
                                   i i   '-t
                              -    -    -

--683%
                                                                                               w
                                                                                               z
                              D Volatilization D Gas Absorption D Wet Deposition II Dry Deposition
Figure C6. Loadings as a proportion of total deposition to Lake Huron for 1998.  * indicates substances for which no volatili-
zation estimates could be made because of lack of water concentration data. Refer to Table A3 for missing air concentration
data.
                                                            59

-------
                                                     Lake Erie 1997
                              Volatilization d Gas Absorption n Wet Deposition • Dry Deposition
Figure C7. Loadings as a proportion of total deposition to Lake Erie for 1997.  * indicates substances for which no volatiliza-
tion estimates could be made because of lack of water concentration data. Refer to Table A3 for missing air concentration da-
ta.
                                                          60

-------
                                                     Lake Erie 1998
      -400
                              D Volatilization D Gas Absorption  D Wet Deposition II Dry Deposition
Figure C8. Loadings as a proportion of total deposition to Lake Erie for 1998.  * indicates substances for which no volatiliza-
tion estimates could be made because of lack of water concentration data.  Refer to Table A3 for missing air concentration da-
ta.
                                                           61

-------
       100


       50 i


        0


       -50 i


      -loo -•


      -150 -•


      -200 - •


      -250 - •


      -300 - •


      -350 -•
      -400
-HCH
                                                      Lake Ontario 1997
                    -464%
4-1	M-
        4-	4
               4-1	M	1
                       -    ?
         H
         Q
         Q
                         -412%
                                                      m
-480%
                                   OH  OH
                              D Volatilization D Gas Absorption D Wet Deposition II Dry Deposition
Figure C9. Loadings as a proportion of total deposition to Lake Ontario for 1997. * indicates substances for which no volatili-
zation estimates could be made because of lack of water concentration data.  Refer to Table A3 for missing air concentration
data.
                                                            62

-------
                                                     Lake Ontario 1998
 100


 50


  0


 -50


-100 +


-150 •-


-200 - -


-250 - -


-300 • •


-350 - -


-400 - -


-450 - -


-500
                             4-1	M-
                                     4-	+
                                             4J—M	^
                     --634
                               Q
                               Q
                               Q
                            w
                            Q
                            Q
                                                 -600%
m
u
m
u
m
u
                                                              m
                                                              u
                                                                               -656%
                   z
                   w
W
U
w
z
                               Volatilization n Gas Absorption d Wet Deposition • Dry Deposition
Figure CIO. Loadings as a proportion of total deposition to Lake Ontario for 1998. * indicates substances for which no vola-

tilization estimates could be made because of lack of water concentration data. Refer to Table A3 for missing air concentra-

tion data.
                                                            63

-------
Appendix D. Annual IADN Flows (kg/yr), 1992-1998
                           64

-------
Table Dl. IADN annual flows (kg/yr) from 1992 to 1998 for Lake Superior

a-HCH

Y-HCH
dieldrin
p,p' -ODD
p,p'-DDE
p,p' -DDT
HCB
PCB18
PCB44
PCB52


1992
1993
1994
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1996
1998
Wet
Deposition
78
33
38
71
35
65
62
14
19
95
38
27
10
21
62
11
34
20
18
11

17
10
0.89
0.8
0.32
0.74
2.6
38
4
4.6
2.1
2.5
2.3
62
59
48
1.7
3.2
3.9
3.8
53
25
1.2
1.5
1.2
1
0.6
092
3.1
1.6
2
3.4
2.3
1.1
1.4
9.1
1.7
2.2
1.9
2.7
5.3
1.1
1.8
2.1
2.6
1.6
Dry
Deposition
1.1
5.6
12

2.9
1.9
0 65
2 7
2.4
1.9
-
4.2
2.2
7.4
63
25
15
-
15
18
6.1
0.1
-
0.5
-
1.1
0.64
0.39
1.2

0.96
-

.
1.6
1.9

2.4
-
1.4
1.8
0.67
19
0.37
0.42
.
.
.
0.26
0.39
29
1.9

.

0.45
0.92
28
1.7
.
.

0.31
0.56
3.1


Net Gas
Exchanae
390
450
710
-240
-290
-470
140
47
95
65
43
69
-4.6
-500
-540
-500
-240
-200
-220
-280


-
-9.3
4.3
6
5



-18
-14
1.9
-4
21
12

2
7.8
2.6
1.5
47
15
16
24
22
18
25
-71
-74
-71
-14
14
-5
-5.5
-19
-14
-73
-83
51
-057
-2.3
-13
-8
5
34
0.54
Total
Deposition
470
490
760
-170
-250
-460
200
64
120
76
81
100
7.6
-470
-470
-460
-190
-180
-190
-250


-
-7.9
5.1
7.4
6.4



-12
-12
4.4
-1.7
29
73

6.1
11
7.9
7.1
53
59
18
26
23
19
26
-70
-71
-67
-10
17
-2 7
-4.4
-17
-4
-2.8
-4.4
53
2.1
3
-12
-56
10
37
2.1


















PCB101

ZPCB
suite -PCB
suite -PCB
phenan-
threne
pyrene
B(k)F
B(k)F
B(k)F
B(b+k)F
B(b+k)F
B(b+k)F
Bfb+klF
B(a)P
Pb
As
Se
Cd


1992
1993
1994
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1996
1998
Wet
Deposition
1.7
1 6
1.6
2.6
3
35
58
110
63
70
90
75
70
260
180
130
500
190
270
110
160
140
210
460
120
170
83
120
130
92
640
219
229
149
140
160
92
170
49
72
49

-

-
.
.
.



-

.




.
.
.

.

-
-

Dry
Deposition
045
0.74
2.3



27
25
86
47



100
60
310
59
100
96
75
120
74
220
54
91
76
71
52
13
58
159
152
170
143
58
14
39
17
35
39
36

16000
26000





5600
2900





1800
3100





2100
4400


Net Gas
Exchanse
-42
-39
-25
22
3.9
3 2
-1300
-1200
-1000
-300
-380
-210
-230
-5500
-6800
-6800
5700
2200
1600
830
980
67
-58
2600
210
61
28
140
20
70
190
98
99
100
22
21
35
76
34
35
33

-

-


.











.




-
-

Total
Deposition
-40
-37
-21
25
6.9
6.7
-1200
-1100
-850
-180
-290
-140
-160
-5100
-6600
-6400
6300
2500
2000
1000
1300
280
370
3100
420
310
180
310
160
220
990
470
500
390
220
200
170
260
120
150
120

-




.



















                                   65

-------
Table D2. IADN annual flows (kg/yr) from 1992 to 1998 for Lake Michigan

a-HCH

Y-HCH
dieldrin
p,p' -ODD
p,p'-DDE
p,p' -DDT
HCB
PCB18
PCB44
PCB52

1992
1993
1994
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1996
1997
1998
Wet
Deposition
62
44
98
15
40
17
65
120
47
26
6.6
31
13
58
55
62
47
30
24
31

64
16
1.6
1.8
0.36
2.9
3.8
11
3.5
7.4
39
2.5
2.7
22
56
58
9.7
9
4.3
3
2.6
13
1.1
1.4
091
075
0.83
091
1.3
1.6
2.6
1.7
082
1.4
1.4
1.2
9.1
1.8
0.97
1.3
2.8
1.2
1.1
2.3
2.2
1.7
1.9
Dry
Deposition
1.5
4
6.3

34
0.91
1.1
2
1.4
2.2
-
2.3
1.9
8
72
23
20
-
15
18
3.8
0.98
-
1.9
.
0.76
0.99
0.48
1.4
-
1.4
.

.
23
6.2

0.67
.
1.1
2
0.38
13
0.19
0.35
.
.
.
0.18
0.46
1.2
1.1
.
.

0.32
0.67
1.4
1.1

.

0.24
0.55
1.4

.

Net Gas
Exchanae
52
81
120
300
300
200
870
250
490
190
110
150
190


-

-




-
-
.
3.5
5.3


-
-
.
-1.5
-12
44
35

-
.
13
14
24
1.2
-10
8.3
83
16
26
-69
-74
-75
-24
-24
-62
-5.5
-44
-42
-52
-20
-22
-82
-11
-56
-55
-60
2.2
7.1
11
Total
Deposition
120
130
220
320
340
220
940
370
540
220
120
180
200


-

-




-
-
.
4.6
9 2


-
-
.
1
-9.3
68
97

-
.
18
19
27
27
-87
10
9 2
17
27
-68
-72
-72
-20
-22
-5.4
-4.1
-42
-40
-42
-17
-21
-69
-8.2
-55
-53
-56
4.4
88
13

















PCB101

EPCB
suite -PCB
suite -PCB
phenan-
threne
pyrene
B(k)F
B(k)F
B(k)F
B(b+k)F
B(b+k)F
B(b+k)F
Bfb+klF
B(a)P
Pb
As
Se
Cd

1992
1993
1994
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1996
1997
1998
Wet
Deposition
1.4
0.81
1.7
1.4
1.1
1.7
52
86
71
78
48
25
38
350
230
160
360
220
320
180
220
220
130
340
140
220
130
130
110
73
480
258
338
278
170
170
77
160
84
120
89

-

-
.
.
.

-

-
.
.




.

.



-
.
.

Dry
Deposition
0.33
0.66
1.1



16
24
39
41



110
100
160
82
100
97
120
140
140
170
95
110
99
150
56
43
63
198
197
183
288
77
42
63
37
41
48
86

16000






820
1300





910






4500




Net Gas
Exchanse
-26
-23
-29
-9.1
-3 79
-4.3
-1300
-1200
-1400
-330
-320
-51.4
-34


-






-
-


-



-


.

-

-


.

-

-


.

-














-
.
.

Total
Deposition
-24
-22
-26
-7.7
-2.7
-2.6
-1200
-1100
-1300
-210
-270
-26
4









-



-






.






.

-




.

-


















                                   66

-------
Table D3. IADN annual flows (kg/yr) from 1992 to 1998 for Lake Huron

a-HCH




T-HCH






dieldrin






p,p' -ODD






Ff'-VDE






pX-DDT






HCB






PCB18






PCB44






PCB52







1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
Wet
Deposition
170
140
150
220
160
72
40

260
120
110
93
100
130

13
15
19
41
26
17


1.8
38
67
27
6 1
10

3.4
96
7.8
21
6
22

4.1
10
18
45
28
5.8
11
3.3
3.6
1.3
3.6
092
17
4
094




20
5.2
2.5
.


-
7.6
11
2.6




Dry
Deposition

-
-



-

.




.
.
.

.


.
.
.

.

-

-
.

.

-

-
.
.


-

-

.




.

.



-
.
.
.

-

-
.
.
.


Net Gas
Exchange

-500
-490
-50
-63
-15
-82

-34
-19
32
29
56
37

-760
-720
.

.


.
.
.

091
079
-

-
.

-5
-5
-
2 5
2.5
.
.
5.7
4
-35
-14
-18
-35
-28
-16
-17

-28
-29
-14
-15
-0.18
•4.9

-10
-10
-17
-15
-6.3
-6.6

-6.8
-6 7
-7.3
-55
2
0.72
Total
Deposition

-360
-340
170
97
57
-42

230
100
140
120
160
170

-750
-710









28
6.9





16
1


6.6


51
6.8
-29
-3
-15
-31
-27
-12
-16

-24
-28





-4.8
-75





4.2
-4.1










































































PCB101




EPCB




suite-PCB
suite-PCB
phenan-
threne





pyrene






B(k)F
B(k)F
B(k)F
B(b+k)F
B(b+k)F
B(b+k)F
Bfb+kW
B(a)P






Pb






As






Se






Cd







1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
Wet
Deposition
11
6
1.9
-


180
130
110
.




640
320
250
390
760
730

350
190
220
350
680
380
-

-
610

600
420
-

-
350
.
280
210
100000
64000
47000
15000
18000
61000
28000
11000
7500
6500
2200
2700


17000
12000
10000
2700
3100

-
6600
2900
2300
1400
2000
2900
4100
Dry
Deposition













90
71
63
110
140
59

130
77
61
130
160
94

83
48

257
215
158

110
56

100
86
56
11000
8000
11000
7600
13000
12000
7300
2200
1700
1200
710
2900
1500
1200
2700
2400
2600
110
1100
590
570
470
310
410
170
310
490
280
Net Gas
Exchange

0.77
0.74
-6.1
-27
-3.4

-490
-460
-240
-230
-23
-24


.






.




-






-






-














-




-

-





Total
Deposition






-360
-350

























-






110000
72000
58000
23000
31000
73000
35000
13000
9200
7700
2900
5600


20000
14000
13000
2800
4200

-
7100
3200
2700
1600
2300
3400
4400
                                   67

-------
Table D4. IADN annual flows (kg/yr) from 1992 to 1998 for Lake Erie

a-HCH
Y-HCH
dieldrin
pX-DDD
pX-DDE
P,p' -DDT

HCB
PCB18
PCB44
PCB52
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
Wet
Deposition
84
35
19
29
6.3
54
1.5
46
23
22
13
1.7
5 3
0.51
28
32
8.9
12
9.4
9.2
2.4
1.9
3.4
1.4
1.7
2
0.75
072
4.6
4.6
36
7.8
2.6
1.8
037
34
98
14
4.9
23
0.38
088
5.4
04
0.73
034
03
0.23
0.34
0.57
056
1.4
043
035
0.1
055
0.81
1.6
096
0.32
0.43
0.37
0.42
0.729
1
1.7
0.65
06
0.21
Dry
Deposition
1.2
2
3.4
09

025
0.2
0.45
1.3
0.83
06

1.3
0.51
5.6
37
18
11

8.4
77
2
0.21
-
1.2
-
0.72
0.79
0.53
0.65
.
1.2
-


4.3
2.1
1.5
.
1.2
0.64
0.2
6.4
0.21
0.22
.

.
0.12
0.21
0.74
0.6
.


0.23
0.43
0.83
1.2



0.28
0.33
0.85
1.3

.

Net Gas
Exchange
140
290
300
120
44
81
93
60
83
68
45
47
41
38
-300
-120
-110
-110
-110
-82
-80
-

-

-


-

.

-
-26
-25
20
30

.
-99
-12
-17
0.76
.7
-1
-57
-2.8
-0.97
-17
-15
-15
-22
-26
-13
-10
-5.4
-1.1
-5 2
-11
-16
-3.4
-6.3
-5.8
-2.2
-5.2
-86
-13
9
7.6
Total
Deposition
230
330
320
150
50
87
95
110
110
91
59
49
48
39
-270
-84
-83
-87
-100
-64
-70












-24
-25
58
130


-6.4
-11
-16
13
-6.4
-0.05
-5.4
-25
-0.74
-17
-14
-14
-20
-26
-13
-9.9
-46
0.14
-2.8
-88
-16
-3
-5.9
-5.1
-1.1
-3.4
-56
-12
96
7.8












PCB101
SPCB
suite-PCB
suite-PCB
phenan-
threne
pyrene
B(k)F
B(k)F
B(k)F
B(b+k)F
B(b+k)F
B(b+k)F
Bfb+kW
B(a)P

Pb
As
Se
Cd
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
Wet
Deposition
0.48
0.81
1.1
1.4
0.51
0.54
0.25
21
26
41
58
18
13
4.6
500
360
210
530
91
290
89
330
310
160
360
58
210
50
150
140
81
560
158
305
93
180
190
190
50
120
27

-
.
.
.

.

-
.
.
.



-

.




-
-
.

.

Dry
Deposition
028
0.37
0.73
1.4



16
14
29
32



86
100
190
160
190
160
140
110
130
250
210
260
180
170
60
84
100
580
430
376
441
63
57
100
120
100
98

13000
13000





1500
1400





2800
2400





1100
1500




Net Gas
Exchange
-2 2
1
-2.6
-5.2
-6.6
-1.1
-0.74
-200
-100
-200
-220
-310
-160
-120
-

-
1600
-770
3600
3600
-

-
290
-80
370
350
-


52
15
37
39

-
-0.75
-8
5.1
3.3

-

.


.

-






-







-


.

Total
Deposition
-1.4
2.2
-0.77
-2.4
-6.1
-056
-049
-160
-60
-130
-130
-290
-150
-120



2300
-490
4100
3800
-


860
240
760
570
-


1200
600
720
570


290
160
230
130






.





















                                   68

-------
Table D5. IADN annual flows (kg/yr) from 1992 to 1998 for Lake Ontario

a-HCH
T-HCH

dieldrin

p,p' -ODD
p,p'-DDE
P,p' -DDT
HCB
PCB18
PCB44
PCB52
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1996
1997
1998
1992
1993
1994
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
Wet
Deposition
52
32
33
21
31
25
21
50
37
24
26
50
33
11
5.4
3
4.5
6
4.5
2.9
036
0.49
042
059
2.3
2
4.4
2
0.61
5 3
2
11
39
3.3
72
1.1
14
4.1
13
1.3
6.1
3
0.62
0.73
087
0.87
0.56
2 5
028
035
0.81
0.71

.
3.6
5.7
0.66
2
1.4


1.6
1.4
093
2.5
2.5


Dry
Deposition

-

.
.
-


-
-

.



-

.



-
.
.
.

-

-
.
.
.



-

.




-
-
.

-


.
-
.

.

-

-
.



-

-
.
-

Net Gas
Exchange
-80
-54
-23
-57
-11
-18
-44
-82
-1.5
7.9
17
68
3.4
-330
-200
-180
-210
-110
-120


-
.
.
.

-96
-99
-80
.
.
-21
-24
4.4
55
8.2

.
5.7
3.9
-170
-190
-150
-32
-28
-24
-22
-19
-22
-19
-18
-16
-8.7
-10
-19
-21
-18
-20
-19
-10
-10
-18
-22
-18
-11
-9.5
-0.2
-2.1
Total
Deposition
-28
-22
10
15
20
7
-23
42
36
32
43
57
36
-320
-190
-180
-210
-100
-120







-92
-97
-79


-10
-20
7.7
13
9.3


19
5.2
-160
-190
-150
-31
-27
-23
-21
-17
-22
-19
-17
-15


-15
-15
-17
-18
-18


-16
-21
-17
-8.5
.7















PCB101
2PCB
suite-PCB
suite-PCB
phenan-
threne

pyrene
B(k)F
B(k)F
B(k)F
B(b+k)F
B(b+k)F
B(b+k)F
Bfb+kW
B(a)P
Pb
As
Se
Cd
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1996
1997
1998
1992
1993
1994
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
Wet
Deposition
1.7
2.3
0.62
1.8
1.3
-

56
89
15
26
.

70
540
380
250
390
340
64
470
220
130
260
450
210
33

-
173
311
210
259
54

-
63
110
81
76
40000
27000
15000
7600
5000
21000
37000
2900
3100
2100
970
580

.
5500
5000
3900
1300
1100


2600
1300
550
530
390
1100
1600
Dry
Deposition













41
25
44
63
51
52
88
55
48
46
83
72
100
92
79
29
105
249
225
315
86
79
43
29
60
60
69
4500
5300
6100
3300
5100
5100
5800
570
720
630
210
610
650
1000
1000
1600
1800
150
340
600
460
96
99
130
49
100
170
170
Net Gas
Exchange
-1 6
-2.4
-0.84
-6.2
-5.4
-2.4
-2.9
-450
-570
-450
-230
-19
-18
-510

-

-630
-410
-46

-


-110
36
-9 7




3.5
41





-7.6
-8



-


-



-


.

-






-





Total
Deposition
0.1
-0.1
-022
-4.4
-4.1


-390
-480
-440
-200


-400



-190
-18
110




410
310
120




440
620





130
140
45000
32000
21000
11000
10000
26000
43000
3500
3800
2700
1200
1200

.
6500
6600
5700
1500
1400


2700
1400
680
580
490
1300
1800
                                   69

-------
Appendix E. Annual Fluxes to the Great Lakes, 1992-1998
                           70

-------
                           Lake Superior
                                                                                         Lake Michigan
          a-HCH     g-HCH     dieldrin     pp'-DDD    pp'-DDE    p.p'-DCT
                  H1992B19930 1994 01995 B1996 O1997O19!
                                                                 5  6
                                                                 E
                                                                                                                 i
                                                                                                                                i4

                                                                       a-HCH      g-HCH      dieldrin     p,p'-DCD     p,p'-DDE    p,p'-DDT
                                                                                                                                      a-HCH      g-HCH     dieldrin     p,p'-CDD     p,p'-DDE     p,p'-DDT
                                                                                 D1992 11993 Q1994B1995B1996 11997 [
                                                                                                                                               [11992 B1993 n1994n1995|i 1996 |1997 [
                                       a-HCH      g-HCH     dieldrin      p,p'-CDD     p,p'-DDE     p,p'-DDT
                                                 11992 11993 Q1994 Q1995B1996 Q 1997 D
                                                                                                        a-HCH     g-HCH     dieldrin      p,p'-DCD    p,p'-DDE     p.p'-CDT
                                                                                                                 11992 Q1993 Q1994 Q1995 B1996Q 19
Figure El.  Annual  average wet deposition flux (ng/nf/day) of organochlorine pesticides
                                                                                            71

-------
                        Lake Superior
                                                                                 Lake Michigan
                                               iflrn.
ifim.jin   .ninrn.
        a-HCH     g-HCH     dieldrin    p,p'-CDD    p,p'-DDE    p,p'-DDT
                                                                 a-HCH     g-HCH     dieldrin     p,p'-DDD    p,p'-DDE    p,p'-DDT
                • 1992 Q1993 01994 Q1995 1199601997019?
                                                                         • 1992 11993019940199511996019
                                                                                                                                     Data not available for Lake Huron
                              3 04
                              £
                                     a-HCH     g-HCH      dieldrin    p.p'-DDD    p.p'-DCE    p.p'-DDT
                                             • 1992 D1993 D1994 01996 11996 D1997 B199
                                                                                                        Data not available for Lake Ontario
Figure E2. Annual average dry deposition flux (ng/nf/day) of organochlorine pesticides
                                                                                    72

-------
                      Lake Superior
                                                                         Lake Michigan
                       w
       a-HCH    g-HCH    dieldrin    p,p'-CDD   p,p'-DDE    p.p'-CDT
                                                           a-HCH     g-HCH    dieldrin    p,p'-DDD    p,p'-DDE    p,p'-DDT
              [Q1992G1993 n1994p1995« 1996 D
|g1992n1993n 1994Q 1995 B1996 Q1997B199S|
15
£
3
E -
1
ill -15
O
-35


. rJV
1
•u







.
a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p.p'-CDT
                                                                                                                       B 1992 B1993Q1994 Q 1995 B1996Q1997 §19981
                                 a-HCH    g-HCH    dieldrin    p,p'-DDD    p,p'-DDE    p,p'-DDT
                                        |g1992n1993n 1994Q 1995 B1996 B1997B1998|


rJ-TU_ _n




a-HCH
1—1


-48 	 -F
LU



g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT
Figure E3. Annual average net gas exchange flux (ng/nf/day) of organochlorine pesticides.  Positive values denote net gas ab-
sorption, negative values denote net volatilization.
                                                                            73

-------
                    Lake Superior
                                                                       Lake Michigan
20-
(ng/m2/d
D C
s "
EZ
* ID


i



firm j
I w
1 U

a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT
                                                           a-HCH   g-HCH   dieldrin   p,p'-DDD   p,p'-DDE   p,p'-DDT


£
c
Total Flux
3 3




I
i llnfjl


-34 	 >
a-HCH g-HCH d
r^ _ •_


• 	 -32
eldrin p,p'-DDD p,p'-DDE p,p'-DDT
             |n1992n1993 01994019950199601997 G1998|
                                                                11992  H1993
G1994 G1996 B1997 G1998]
|g 1992 D1993 D1994 D1995 • 1996 D 1997 D 1998 |
                                                                                                 Lake Ontario

(ng/m2/d|
D 0
D
E



1 	 35
L
1



a-HCH

1



n
111 [11


IP : :

I
20
B 10
E
1 „
Total Flux
0 0

g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT
|H1992H1993 01994 01995 H1996 01997 H1998J


rr», fTfTlfl rfn ru
LM u' '

-47 	 * .
•|mnj-
U *
E
a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT
JB1992B1993 Q1994Q1995 §1996 Q1997 H1998 I
Figure E4. Annual average total flux (ng/m2/day) of organochlorine pesticides
                                                                          74

-------
                         Lake Superior
                                                                                   Lake Michigan
           18       PCB44      PCB52       PCB101     SutePCffO.I
                                                             0.3
                                                                                                                      - 0.6 +
                                                                                                                      =
                                                                                                                      c 0.5-H
                                                                     18       PCBM       PCB52       PCB101     SuitePCB*0.1
                                                                                                                             PCB18       PCB44      PCB52       PCB101     SuitePCB'0.1
                |g1992n1993n 1994Q 1995 B1996 Q1997B199S|
|g1992 n1993n199401995 11996111997 B1998|
992 11993 01994 O1995«1996n 1997 111998 |
                               I

                               So.6
                                       218       PCB44       PCB52       PCB101     SuitePCB'0.1
                                                                                                  !18       PCB44      PCB52       PCB101     SuitePCB'0.1
                                              « :::n ::: g-  -g-  :m' • a'
                                                                                                        « :::n ::: g-  -g- :m' • a'
Figure E5. Annual average wet deposition flux (ng/nf/day) of PCBs.  Note that sum-PCB is multiplied by 0.10.
                                                                                     75

-------
                         Lake Superior
                                                                                  Lake Michigan
  S 0.25
  I
  £ "
    0.05
                                                           I °'15
                                                     H        0
          PCB18       PCB44      PCB52       PCB101     SuitePCffO.I
                                                                   PCB18      PCB«       PCB52      PCB101    SuitePCB-0.1
                [•19921119930199411995 11996 a  m   \
                                                                          j 1992 n 1993 Q1994 Q1995^1996 n 1997 (§193
                                                                                                                                     Data not available for Lake Huron
                                      PCB18       PCB44      PCB52      PCB101     SuitePCB'0.1
                                             [01992111993 019940199511996111997 B1998|
                                                                                                        Data not available for Lake Ontario
Figure E6. Annual average dry deposition flux (ng/nf/day) of PCBs.  Note that sum-PCB is multiplied by 0.10.
                                                                                    76

-------
                      Lake Superior
                                                                           Lake Michigan
  1 -1
              'LpJ-LjJiJE
w
pn^
f
        PCB18      PCB44       PCB52      PCB101     SutePCB'0.1
                                                            PCB18      PCB44      PCB52      PCB101     SuitePCB'0.1
                                                                                                                 PCB18      PCB44      PCB52      PCB101     SutePCB*0.1
               |l!1992«1993n19940ia5 I
                                    |g1992n1993n 1994 01995 11996 B1997I11998|
                                                             [01992H1993 n1994Q1995ll1996 11997 B1998 |
                                  PCB18      PCB44      PCB52      PCB101     SuitePCB*0.1
                                                                                       PCB18       PCB«      PCB52      PCB101     SuitePCB-0.1
                                         [0199201993 n 1994 O1995 B1996G1997111998 |
                                                               |§1992 ^1993 n 1994 Q1995^1996 n1997 Q199
Figure E7. Annual average net gas exchange flux (ng/nf/day) of PCBs.  Note that sum-PCB is multiplied by 0.10.  Positive val-
ues denote net gas absorption, negative values denote net volatilization.
                                                                             77

-------
                      Lake Superior
                                                                           Lake Michigan
                                                                                                                                  Lake Huron
   C -3


   I,
       I
                        '18    ~'12
a -2
E -J

L
                                                                                    Jl
                                ra
    i
                                                      E
                                                      a -2
f-4
                                                                    -n	^-
         PCB18     PCB44     PCB52     PCB101    SuitePCB*0.1
                                                               PCB18     PCB44      PCB52     PCB101   SuitePCB*0.1
                                                                                                                     PCB18      PCB44      PCB52      PCB101   SuitePCB*0.1
                                                  Lake Erie
                                                                                                       Lake Ontario
                                    PCB18     PCB44     PCB52     PCB101    SuitePCB*0.1
                                                                                          PCB18     PCB44      PCB52     PCB101   SuitePCB*0.1
                                                                                               11992 B1993D1994D1995B1996D1997B1998
Figure E8. Annual  average total flux (ng/m /day) of PCBs.  Note that sum-PCB is multiplied by 0.10.
                                                                               78

-------
                  Lake Superior
                                                             Lake Michigan
 S 60

 I™
 3
 1 40
Vy^fcrdin
                                rn-T
            |g1992n1993n 1994 01995 11996 B1997I11998|
                                    3 60

                                    I 50
^Ad^
                                                           PYR     B(k)ForB(b*k)F*
                                              |n1992G1993 G199401995B1996 0199711199
                                 3 60

                                 I 50
                                                                                                      PYR     B(k)F or B(b*k)P
iliiT
                                           |n1992G1993 G199401995B1996 0199711199
                                 |l1992a1993 01994B1995«1996a1997 11199
                                                                   [•199211993n 1994 01995 11996 B1997I11998|
Figure E9. Annual average wet deposition flux (ng/nf/day) of PAHs. * 1992-1994 : B(b)F; 1995-1998 : B(b+k)F
                                                               79

-------
                   Lake Superior
                                                               Lake Michigan

E 20
c
1
.2
Q.
&
Q






n
fk -Ti ftl-tr
PHEN PYR

6"

1
1
,— 1
B(k)ForB(b+k)F* B(a)P

E ,„
I
J
n-rrfli 11 f"
II" 1,1 [ .rri-llll.fHMl
PHEN PYR B(k)ForB(b+k)P B(a)P






PHEN PYR B(k)ForB(b+k)P





l.llh
B(a)P
                        =
                        I15
                        ^
                        J 10
                                                       — 40.2
                                                       -46.6
I

| 10
                                       PYR      B(k)ForB(b+k)F*
                                   « :::n ::: g- -g- :m' • a'
                                                                                   PYR     B(k)ForB(b*k)F*
Figure E10. Annual average dry deposition flux (ng/m2/day) of PAHs.  * 1992-1994 : B(b)F; 1995-1998 : B(b+k)F
                                                                 80

-------
                    Lake Superior
             [Q1992G1993 n1994p1995g 1996 D
                                                             Data not available for Lake Michigan
                                                                                                             Data not available for Lake Huron
                                          FYR     B(k)F or B(b+k)P
                                    |g1992n1993n 1994Q 1995 B1996 Q1997B199S|
                                                                       *   'T
                                                                       I  5°-{J
                                                                                         PYR      B(k)ForB(b+k)F*     B(a)P
[•1992B1993H1994 0
 Figure Ell.  Annual average net gas exchange flux (ng/nf/day) of PAHs.  Positive values denote net gas absorption, negative
values denote net volatilization.   *  1992-1994 : B(b)F; 1995-1998 : B(b+k)F
                                                                     81

-------
                    Lake Superior
                      PYR     B(k)F or B(b+k)F*    B(a)P
               1992 B1993 D1994 D 1995 B1996 B1997 B1998
Data not available for Lake Michigan
Data not available for Lake Huron
                                                                                250





                                                                                200





                                                                                150
                                                                                                Lake Ontario
                                                                                -100




                                                                                -150




                                                                                -200




                                                                                -250




n
u u


. It





                                               PYR     B(k)F or B(b+k)F*    B(a)P
                                        1992 • 1993 D 1994 D 1995 • 1996 • 1997 • 1998
                                                                                                 PYR    B(k)F or B(b+k)F*     B(a)P
                                                                                          1992 • 1993 D 1994 D 1995 • 1996 • 1997 • 1998
Figure E12. Annual average total flux (ng/m2/day) of PAHs.  * 1992-1994  : B(b)F; 1995-1998 : B(b+k)F
                                                                          82

-------
                 Data not available Lake Superior
                                                                   Data not available for Lake Michigan
                                           Data not available for Lake Erie
                                                                                                        I 2000 f-

                                                                                                        S
                                                                                                        a
                                                                                                                        n-n_
                                                                                                                     |o :::p ::: g- -g-  :m' • a' 'm'  \
                                                                                                            Se          Cd
                                                                                           [•199211993n 1994 01995 11996 O  ~m  \
Figure E13. Annual average wet deposition flux (ng/nf/day) of metals
                                                                            83

-------
                Data not available for Lake Superior
                                                                  Data not available for Lake Michigan
                                          Data not available for Lake Erie
                                                                                                      i soo
                                                                                                                   |1992 |]1993 Q 1994 g1995 |1996 n 1997 a 1998 I
                                                                                            rnurfl
-rfh
                                                                                         [•19921119930199411995 11996 a   m  \
Figure E14. Annual average dry deposition flux (ng/nf/day) of metals
                                                                          84

-------
                    Data not available Lake Superior
                                                 Data not available for Lake Erie
                                                                            Data not available for Lake Michigan
                                                                                      I, 4000
                                                                                      E 3000

                                                                                      "~ 2000
                                                                                                                  s
                                                                                                                  I) 4000
                                                                                                                                    rh-i__
                                                                                                                              11992 B1993 a 1994 a 1995 B 1996 a 19971
                                                                                                          Lake Ontario
                                                                                                   11992 B1993 o 1994 o 1995 B 1996 o 1997 B 19!
Figure El5. Annual average total flux (ng/m /day) of metals
                                                                                  85

-------
Appendix F. Annual Fugacity Ratios for IADN Substances, 1992-
1998
                           86

-------
Table Fl. Fugacity ratios (absorption over volatilization) for gas exchange loadings
over the Great Lakes


a-HCH






y-HCH






dieldrin






a-
endosulfar





c/s-
chlordane





trans-
chlordane





trans-
nonachlor





1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
Lake
Superior
1.7
1.7
2.3
0.8
0.73
0.66
0.56
2.1
1.4
1.8
1.7
1.5
1.7
0.92
0.14
0.11
0.14
0.19
0.18
0.17
0.097
-

-
0.95
0.65
2.1
1.7
-

-
0.73
0.55
0.45
0.26

-
-
1.4
0.51
0.22
0.083

-

0.35
0.31
0.38
0.4
Lake
Michigan
1.1
1.1
1.2
3.9
4
3.1
2.1
12
4.1
7.1
11
7.5
7.2
7.3
-
-


-


-

-
-
-

-
-

-
1
0.79
1.1
0.76

-
-
0.83
0.7
1
0.65

-

0.18
0.14
0.21
0.2
Lake
Huron

0.38
0.38
0.84
0.78
0.9
0.65

0.69
0.79
1.9
1.9
3.7
2.5
-
0.062
0.062

-


-

-
-
-

-
-

-
0.54
0.56
0.62
0.62

-
-
0.45
0.51
0.85
0.79

-

0.17
0.18
0.22
0.19
Lake
Erie
1.5
3.4
3.5
1.9
1.4
2.2
2.3
2
2.8
2.4
2.9
3
2.4
2.3
0.1
0.31
0.26
0.21
0.16
0.27
0.23
-

-
910
530
6600
6000
-

-
2.1
1.2
1.1
0.91

-
-
1.7
0.96
0.51
0.5

-

0.53
0.4
0.38
0.36
Lake
Ontario
0.62
0.67
0.88
1
0.9
0.79
0.55
0.82
0.95
1.2
1.6
1.9
1.3
1.1
0.06
0.15
0.16
0.08
0.07
0.17
0.12
-

-
2300
2000
2800
3300
-

-
0.59
0.58
0.69
0.52

-
-
0.44
0.39
0.89
0.57

-

0.26
0.2
0.25
0.18



















































p ,p '-ODD






pf'-DDE






p,p'-DDT






HCB






PCB18






PCB44






PCB52






1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
Lake
Superior

_
-
1.3
2.7
100
65

_
-
0.34
0.29
1.2
0.59
4.4
2.8

1.2
2
1.4
1.2
1.7
1.2
1.2
1.4
1.4
1.3
1.4
0.084
0.083
0.073
0.26
1.9
0.43
0.41
0.26
0.46
0.68
0.64
3.4
0.93
0.73
0.43
0.65
1.2
0.66
2.4
1.2
1.1
Lake
Michigan

_
-
-

39
45

_
-


0.96
0.56
13
11


-
6.5
6.1
1.3
1
0.86
1.2
1.2
1.3
1.5
0.11
0.093
0.082
0.14
0.13
0.36
0.59
0.21
0.29
0.12
0.29
0.17
0.29
0.35
0.16
0.21
0.14
1.7
1.5
12
18
Lake
Huron

_
-
-

10
7.6

_
-


0.48
0.51
-
2.3
2.4

-
4.8
3.2
0.001 1
0.74
0.67
0.56
0.57
0.74
0.68
-
0.22
0.17
0.52
0.4
1
0.63

0.18
0.17
0.14
0.12
0.3
0.24

0.42
0.37
0.35
0.43
1.5
1.2
Lake
Erie

_
-
-

-


_
-


0.37
0.31
26
39
19

-
0.57
0.48
0.51
1
0.72
0.96
0.78
0.93
0.96
0.26
0.29
0.19
0.14
0.067
0.27
0.29
0.54
0.91
0.49
0.45
0.2
0.75
0.48
0.6
0.86
0.58
0.48
0.22
30
32
Lake
Ontario

_
-
-

-

0.14
0.17
0.23


0.4
0.29
3.6
4
6.1

-
4.2
3.1
0.11
0.12
0.17
0.41
0.46
0.49
0.45
0.28
0.25
0.26
0.28
0.31
0.51
0.33
0.13
0.14
0.15
0.11
0.095
0.24
0.17
0.28
0.2
0.26
0.3
0.34
0.97
0.67
                                      87

-------
Table Fl (continued)


PCB101






SPCB




suite-PCB
suite-PCB
phenan-
threne





pyrene






B(k)F
B(k)F
B(k)F
B(b+k)F
B(b+k)F
B(b+k)F
Bfb+MF
B(a)P






I(l,2,3-cd)P






sum-PAH
(UNECE)





1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
1992
1993
1994
1995
1996
1997
1998
Lake
Suoerior
0.11
0.22
0.47
0.93
2.6
4.5
3.7
0.15
0.26
0.3
0.53
0.28
0.38
0.32
0.5
0.36
0.35
4.1
2.5
2.1
1.5
3.6
1.2
0.86
15
2.4
1.4
1.1
70
10
36
36
23
71
53
1.4
1.3
1.6
14
8.3
10
7.3
-
-
-
28000
30000
35000
24000
-
-
-
28
19
20
23
Lake
Michiaan
0.2
0.34
0.17
0.31
0.28
0.35
0.54
0.13
0.21
0.1
0.23
0.22
0.52
0.84
-
-
-
-
-
-
_
-
-
-
-
-
-
-
-
-
-
-
-
-
_
-
-
-
-
-
-
-
-
-
-
-
-
-
_
-
-
-
-
-
-
-
Lake
Huron
-
1.4
1.4
0.18
0.22
0.47
0.37
-
0.15
0.16
0.28
0.21
0.23
0.15
-
-
-
-
-
-
_
-
-
-
-
-
-
-
-
-
-
-
-
-
_
-
-
-
-
-
-
-
-
-
-
-
-
-
_
-
-
-
-
-
-
-
Lake
Erie
0.69
1.2
0.58
0.42
0.28
0.79
0.84
0.4
0.69
0.32
0.31
0.091
0.38
0.42
-
-
-
1.3
0.84
3.6
3.8
-
-
-
1.4
0.87
3.2
3
-
-
-
3.4
1.8
9.8
9.6
-
-
-
0.96
0.62
1.6
1.4
-
-
-
2500
1700
8000
6800
-
-
-
2.4
1.4
4.6
4.4
Lake
Ontario
0.71
0.62
0.85
0.23
0.28
0.52
0.38
0.24
0.11
0.19
0.21
0.17
0.21
0.15
0.69
-
-
-
-
0.63
0.71
0.79
-
-
-
-
0.58
1
0.28
-
-
-
-
1.5
6.4
-
-
-
-
-
0.22
0.27
-
-
-
-
-
-
_
-
-
-
-
-
-
-
                                     88

-------