ATMOSPHERIC DEPOSITION OF TOXIC SUBSTANCES TO THE GREAT LAKES: IADN RESULTS TO 1996 tateertfc ' U Elisabeth Galarneau Air Quality Research Branch, Meteorological Service of Canada, Environment Canada Celine V. Audette Angela Bandemehr Centre for Atmospheric Research Experiments, Meteorological Service of Canada, Environment Canada Office of International Activities, US Environmental Protection Agency Dora Basu School of Public and Environmental Affairs and Department of Chemistry, Indiana University Terry F. Bidleman Air Quality Research Branch, Meteorological Service of Canada, Environment Canada Kenneth A. Brice Air Quality Research Branch, Meteorological Service of Canada, Environment Canada Deborah A. Burniston National Water Research Institute, Environment Canada C.H. Chan Ecosystem Health Division, Ontario Region, Environment Canada Frank Froude Centre for Atmospheric Research Experiments, Meteorological Service of Canada, Environment Canada Ronald A. Kites School of Public and Environmental Affairs and Department of Chemistry, Indiana University Environmental Careers Organization/Great Lakes National Program Office, US Environmental Protection Agency Ecosystem Health Division, Ontario Region, Environment Canada Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment Matt F. Simcik Division of Environmental and Occupational Health, School of Public Health, University of Minnesota Melissa L. Halting Melanie Neilson DanOrr William M.J. Strachan National Water Research Institute, Environment Canada Raymond M Hoff Department of Physics and Joint Center for Earth Systems Technology, University of Maryland Baltimore County ------- Atmospheric Deposition of Toxic Substances to the Great Lakes: IADN Results to 1996 Published by Environment Canada and the United States Environmental Protection Agency, 2000 ISBN: 0-662-29005-4 Public Works and Government Services Canada Catalogue Number: En56-156/2000E-IN US EPA Report Number: EPA 905-R-00004 Report available in printed form from Air Quality Research Branch Environment Canada 4905 Dufferin Street Toronto ON M3H 5T4 Canada and in electronic form at www.tor.ec.gc.ca/IADN/ Great Lakes National Program Office U.S. Environmental Protection Agency 77 West Jackson Boulevard (G17-J) Chicago IL 60604 U.S.A. www.epa.gov/glnpo/iadn/ ------- Map of the IADN Network lilt e grill eel Atmospheric Pep owl Ion Nctwoilc M e i" St at s -:= ^Sturgeon Point IADN Results to 1996 Page i ------- IADN Results to 1996 Page ii ------- ATMOSPHERIC DEPOSITION OF TOXIC SUBSTANCES TO THE GREAT LAKES: IADN RESULTS TO 1996 Executive Summary The primary objective of this document is to report biennial loadings estimates for the atmospheric deposition of toxic substances to the Great Lakes for the years 1995 to 1996. Atmospheric deposition is the phenomenon by which airborne substances are transferred to water, soil or vegetation at ground level. In IADN, three deposition processes to the Great Lakes are considered: wet deposition by precipitation, dry particle deposition by sedimentation, and net diffusive gas exchange that combines the effects of absorption from air to water with volatilisation from water to air. The loading estimates presented herein are based on measurements taken largely at the IADN Master Stations, of which there is one per lake. Substances considered include those traditionally tracked by IADN, a- and y-hexachlorocyclohexane, dieldrin,p,p '-DDE, p,p '-DDT, andp,p '-DDD hexachlorobenzene (HCB) and polychlorinated biphenyls expressed as £PCB and four individual PCBs: 18, 44, 52 and 101 four poly cyclic aromatic hydrocarbons (PAHs): phenanthrene, pyrene, benzo(k)fluoranthene, and benzo(a)pyrene four trace elements: lead, arsenic, selenium and cadmium, as well as others reported here for the first time, trans- and c/'s-chlordane and trans-nonadtior a- and p-endosulphan and endosulphan sulphate an expanded suite of PAHs. The loadings have been determined in a manner consistent with previous IADN reports, although refinements to the model include an update to the database of physicochemical parameters used in the calculations and the use of measured rather than estimated wind speeds. As a result of these refinements, loadings presented here are not strictly comparable to those presented in previous reports. In order to develop a uniform picture of network loadings over time, results have been recalculated for the period 1992-1994 using the same model assumptions and parameters as used for 1995-96. Temporal trends discussed in this report are based on those recalculated values. In examining the loadings of toxic substances to the Great Lakes, three fundamental issues are considered: the magnitude of the loadings, the manner in which each loading component contributes to the total, and the variation or trends in the loadings across the basin and over IADN Results to 1996 Page iii ------- many years. These loadings are presented in terms effluxes (mass/unit area/unit time; viz. ng/m2/d) in order to account for differences between lakes due to their areas. Typical fluxes of banned organochlorine pesticides are on the order of 0.1 to 1 ng/m2/d and only regularly exceed 10 ng/m2/d for the gas exchange of a-HCH and dieldrin. Fluxes of individual PCB congeners tracked by IADN are typically between 0.1 and 1 ng/m2/d for each loading component, similar to many of the banned organochlorine pesticides, although seasonal volatilisation fluxes of £PCB can be higher than 50 ng/m2/d. HCB gas exchange fluxes are in the 1 to 10 ng/m2/d range and fluxes of current-use pesticides y-HCH and the endosulphans are on the order of 1 to 5 ng/m2/d. Inputs to the lakes of pesticides and PCBs are dominated by gas exchange and wet deposition. Dry particle concentration measurements ceased after 1995 due to low reported levels, but loading estimates presented here show that dry particle deposition of dieldrin, p,p '-DDD and PCBs may be significant when compared to the other deposition processes. Rates of dieldrin and £PCB volatilisation are greater than gas absorption so the lakes are acting as sources of these substances to the atmosphere. Inputs of PAHs and metals are larger than those of pesticides and PCBs as expected by their continued emission to the environment. PAH fluxes range from 1 to 1000 ng/m2/d depending on species and loading process, and fluxes of trace metals reach values as high as 2000 ng/m2/d. Since metals are non-volatile, they are subject only to wet and dry deposition with the wet fluxes typically being the larger of the two. Available data indicate that PAH volatilisation from the lakes is small compared to the other flux terms, and gas absorption is substantial for phenanthrene and pyrene while the higher molecular weight PAHs are delivered mostly by wet and dry particle deposition. As part of its quality assurance program, IADN has begun a new set of intercomparison studies between its participating agencies. Until results are available, comparisons of depositional behaviour between lakes and over time have been limited to those situations where data were generated by the same operating agency. Wet deposition fluxes are generally decreasing in time for the banned OC pesticides while dry deposition and gas exchange fluxes have been variable. The temporal trend in gas exchange is generally toward air-water equilibrium. For PCBs, wet deposition is steady in time while dry deposition was increasing before measurements ceased in 1995. Gas exchange of PCBs is in the direction of volatilisation from all lakes but is generally approaching air-water equilibrium. Wet and dry particle deposition of PAHs show no consistent trends in time though levels increase from west to east across the basin. Little net gas exchange flux information is IADN Results to 1996 Page iv ------- presented for PAHs since water concentration data are sparse. Deposition of metals is limited to wet and dry deposition with wet deposition declining in time and dry deposition being variable. Loading estimates produced by IADN have traditionally been based on the assumption that Master Stations located at remote sites on the lakes are characterizing the regional background deposition. However, strong inputs with more limited geographic influence are also likely to exist near cities and industrial areas. Using the case of Chicago on Lake Michigan as an example, data from 1996 were used to assess the impact of air pollution from urban centres on the deposition to the lakes. The IADN calculation was modified to include a small lake sub- area influenced by the high concentrations measured at Chicago and, though results should be viewed as lower-bound estimates when compared to other studies, deposition from Chicago sources is still estimated to be substantial for certain pesticides and PCBs and for all PAHs. Further work is needed to correctly characterize the lake area affected by urban air pollution and deduce effective ways of incorporating significant urban centres in IADN loading estimates. IADN Results to 1996 Page v ------- IADN Loadings (kg/yr) From 1992 to 1996 Lake Superior a-HCH Y-HCH dieldrin P.P'-DDD P.P'-DDE P,P'-DDJ HCB PCB18 PCB44 PCB52 1QQ9 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 Wet Deoosition 78 33 38 28 71 62 14 19 95 38 21 69 11 34 20 17 in 0.89 OS 2.6 3.8 4 4.6 2.1 6.2 59 48 1 7 32 53 25 1 9 1.5 1.2 0 92 3.1 1.6 2 34 1.4 9 1 1.7 9 9 1.9 1 1 1.8 2.1 26 2.6 Drv Deoosition 1 1 56 19 4.7 0 65 2.7 2.4 1.9 _ 7.4 63 25 15 _ 6 1 0.1 0.5 0 39 1.2 0.96 1.6 1 9 94 0 67 19 0 37 0 42 0 26 0 39 29 1.9 0 45 0 99 2.8 1 7 0 31 0 56 3.1 2.4 Net Gas Exchanae 390 450 710 -230 -940 140 47 95 65 43 -500 -540 -500 -940 -200 _ -9.3 43 _ -18 -14 21 19 9 7.8 47 15 16 24 22 -71 -74 -71 -14 14 -19 -14 -7.3 -8 3 51 -13 -8 5 -99 34 Total Deoosition 470 490 760 -200 200 64 120 76 _ -470 -470 -460 -190 _ _ -7.9 _ -12 29 73 6 1 53 59 IS 26 -70 -71 -67 -10 -17 -4 -2.8 -44 -19 -56 10 -4.9 PCB101 SPCB phenan- threne pvrene B(k)F B(k)F B(k)F B(b+k)F Bfb+k~lF B(a)P Pb As Se Cd 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 Wet Deposition 1 7 1.6 1 6 3.1 96 58 110 63 70 90 260 ISO 130 500 190 160 140 910 460 190 120 130 92 640 219 140 160 92 170 49 _ Drv Deposition 0 45 0.74 93 1.4 27 25 86 47 _ 100 60 310 59 100 190 74 990 54 91 52 13 58 159 152 58 14 39 17 35 16000 96000 5600 2900 1SOO 3100 2100 4400 _ Net Gas Exchanae -49 -39 -95 -094 99 -1300 -1200 -1000 -300 -380 -5500 -6SOO -6800 5700 2200 9SO 67 -5S 2600 910 140 20 70 190 98 22 91 35 76 34 _ Total Deposition -40 -37 -91 36 -1200 -1100 -850 -180 _ -5100 -6600 -6400 6300 2500 1300 280 370 3100 490 310 160 220 990 470 220 900 170 960 120 IADN Results to 1996 Page vi ------- IADN Loadings (kg/yr) From 1992 to 1996 Lake Michigan o^HCH Y-HCH dieldrin P.P' -ODD P.P' -DDE P.P' -DDT HCB PCB18 PCB44 PCB52 10Q9 iqq3 10Q4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Wet 69 44 qs 56 1 S 65 190 47 96 66 58 55 62 47 30 6.4 16 1 6 1 8 3 8 1 1 3 S 74 3q 99 56 58 q7 q 96 13 1 1 1 4 0.91 091 1.3 1.6 2.6 1.7 1.4 1 9 q i 1 8 oq? 1 9 1 1 9 3 3 9 9 Drv 1 5 4 63 4 S 1 1 9 1 4 9 9 8 7.2 23 20 _ 3.8 oqs i q 048 1 4 1 4 93 69 067 038 13 0 19 035 _ 018 0.46 1.2 1.1 _ 032 067 1 4 1 1 094 055 1 4 9 Net Gas FxAancm 59 81 190 350 300 870 950 4qo 190 110 _ _ _ 44 35 94 1 9 -10 8 3 8.3 -69 -74 -75 -24 -24 -44 -49 -59 -90 -99 -56 -55 -60 3 9 9 Total 190 130 990 410 q40 370 540 990 _ _ _ 68 q? 97 97 -8 7 10 _ -68 -72 -72 -20 _ -42 -40 -49 -17 -55 -53 -56 8 PCB101 SPCB phenan- threne pyrene BlYlF BflflF BiVlF Bfb+k)F Rili+FiF BfalP Pb As Se Cd iqq9 iqq3 iqq4 iqqs iqq6 iqq9 iqq3 iqq4 iqqs iqq6 iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Wet 1 4 081 1 7 9 1 1 4 59 86 71 78 48 350 230 160 360 220 220 220 130 340 140 130 110 73 480 958 170 170 77 160 84 _ _ _ _ Drv 033 066 1 1 1 6 16 94 3q 41 110 100 160 82 100 140 140 170 qs 110 56 43 63 19S 197 77 49 63 37 41 16000 _ 820 1300 _ _ 910 4500 Net Gas F.mVianoB -96 -93 -99 .q 3 _q i -1300 -1900 -1400 -330 -390 _ _ _ Total -94 -99 -96 -5 6 -1900 -1100 -1300 -910 _ _ _ IADN Results to 1996 Page vii ------- IADN Loadings (kg/yr) From 1992 to 1996 Lake Huron o^HCH Y-HCH dieldrin P.P' -ODD P.P' -DDE P.P' -DDT HCB PCB18 PCB44 PCB52 10Q9 iqq3 10Q4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Wet 170 140 ISO 990 160 960 190 110 q3 13 15 19 41 1 8 3 8 67 10 3 4 qe 78 99 4 1 10 IS S X 1 1 3 3 3 6 1.3 17 4 oq4 _ 20 S 9 9 S 76 1 1 9 6 Drv _ _ _ _ _ _ _ Net Gas FxAancm -SOO -4qo -SO -fi3 -34 -19 39 9q _ -760 -720 _ _ 9 S 9 S -35 -14 -IS -35 -28 -28 -29 -14 -15 -10 -10 -17 -15 -fi S -67 -73 -5 5 Total _ _ _ _ _ _ _ PCB101 SPCB phenan- threne pyrene BlYlF BflflF BiVlF Bfb+k)F Rili+FiF BfalP Pb As Se Cd iqq9 iqq3 iqq4 iqqs iqqfi iqq9 iqq3 iqq4 iqqs iqqfi iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqfi iqq9 iqq3 iqq4 iqqs iqqfi iqq9 iqq3 iqq4 iqqs iqqfi iqq9 iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Wet 11 e i q ISO 130 no _ 640 320 250 3qo _ 350 iqo 990 350 eio 350 100000 64000 47000 15000 18000 11000 7500 6500 2200 2700 17000 19000 10000 9700 3100 6600 9qoo 9300 1400 9000 Drv _ qo 71 63 110 _ 130 77 61 130 S3 48 957 110 56 100 11000 8000 11000 7600 13000 2200 1700 1200 710 2qoo 2700 9400 9600 110 1100 470 310 410 170 310 Net Gas F.mVianoB 077 074 -77 -6 1 -4qo -460 -940 -930 _ _ _ Total _ 1 1 0000 79000 58000 93000 31000 13000 q20o 7700 2qoo 5600 20000 14000 13000 9SOO 4900 7100 3900 9700 1600 9300 IADN Results to 1996 Page viii ------- IADN Loadings (kg/yr) From 1992 to 1996 Lake Erie o^HCH Y-HCH dieldrin P.P' -ODD P.P' -DDE P.P' -DDT HCB PCB18 PCB44 PCB52 10Q9 iqq3 10Q4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Wet 84 35 1Q 9q 63 46 93 99 13 1 7 28 32 sq 12 9.4 1.9 3.4 1 4 1 7 9 46 46 3 6 7 8 96 34 qs 1 5 14 4q oss S4 04 073 0.34 034 0.57 056 1.4 0.43 055 081 1 6 oqe 039 049 0 79q 1 1 7 Ofi5 Drv 1 9 9 34 oq 045 1 3 083 06 56 3.7 18 11 _ 2 0.21 1 9 053 065 1 9 43 9 1 1 5 09 64 091 099 _ 0.12 0.21 0.74 06 _ 023 043 083 1 9 098 033 085 1 3 Net Gas FxAancm 140 9qo 300 190 44 60 S3 68 45 47 -300 -120 -110 -110 -110 _ 90 30 14 -17 076 -7 -1 -5.7 -17 -15 -15 -22 -26 -54 -1 1 -5 9 -11 -16 -5 8 9 9 -5 9 -8 6 -13 Total 930 330 390 150 110 110 91 sq -270 -84 -83 -87 _ _ 58 130 -16 13 -64 -005 _ -17 -14 -14 -20 _ -46 0 14 -9 8 -8 8 -5 1 -1 1 -3 4 -56 PCB101 SPCB phenan- threne pyrene BlYlF BflflF BiVlF Bfb+k)F Rili+FiF BfalP Pb As Se Cd iqq9 iqq3 iqq4 iqqs iqq6 iqq9 iqq3 iqq4 iqqs iqq6 iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Wet 048 081 1 1 1 4 051 91 96 41 58 18 500 360 210 530 91 330 310 160 360 58 150 140 81 560 158 180 iqo q7 iqo 50 _ _ _ _ Drv 098 037 073 1 4 16 14 9q ^9 86 100 190 160 190 110 130 950 910 960 60 84 100 580 430 63 57 qs 100 190 13000 13000 _ 1500 1400 _ _ 9800 9400 1 100 1500 Net Gas F.mVianoB -9 9 1 -96 -5 9 -66 -900 -100 -900 -990 -310 1600 -770 9qo -SO 59 15 -075 -8 _ _ Total -1 4 9 9 -077 -9 4 -160 -60 -130 -130 2300 -4qo S60 940 1900 600 9qo 160 _ _ IADN Results to 1996 Page k ------- IADN Loadings (kg/yr) From 1992 to 1996 Lake Ontario a-HCH Y-HCH dieldrin P.P' -ODD P.P' -DDE P.P' -DDT HCB PCB18 PCB44 PCB52 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 Wet Deoosition 52 39 33 21 31 50 37 24 13 96 11 54 ^ 39 4.5 9 9 036 049 049 059 4.4 2 061 53 2 33 79 1.1 14 4 1 6.1 3 069 073 087 9 5 098 035 081 071 3.6 5.7 066 9 1.4 1.6 1 4 093 2.5 9 5 Drv Deoosition _ _ _ _ _ _ _ _ _ _ _ _ _ Net Gas Exchanae -80 -54 -93 -5.7 -1 1 -89 -1.5 7.9 19 17 -330 -900 -180 -230 -210 _ -96 -99 -SO 44 S 5 8.2 _ -170 -190 -150 39 -28 -19 99 -19 -18 -16 -19 -21 -IS -90 -19 -18 99 -18 -11 -9 5 Total Deoosition _ _ _ _ _ _ _ _ _ _ _ _ _ PCB101 SPCB phenan- threne B(k)F B(k)F BfkW B(b+k)F B(b+k)F Bfa~lP Pb As Se Cd 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 Wet Deposition 1.7 9 3 069 1.8 1 3 56 89 15 38 96 70 540 380 110 250 64 470 220 130 960 33 173 311 54 _ 63 110 40000 27000 15000 7600 5000 9900 3100 2100 970 580 5500 5000 3900 1300 1100 2600 1300 550 530 390 Drv Deposition 41 95 44 28 63 88 55 48 46 83 92 79 99 105 249 86 79 43 29 60 4500 5300 6100 3300 5100 570 790 630 210 610 1000 1600 1800 150 340 96 99 130 49 100 Net Gas Exchanae -1.6 -94 -0 84 -62 -54 -450 -570 -450 -930 -930 -510 _ -46 -9.7 _ _ Total Deposition -400 _ 110 120 45000 32000 91000 11000 10000 3500 3800 2700 1200 1900 6500 6600 5700 1500 1400 2700 1400 680 580 490 IADN Results to 1996 Pagex ------- DEPOT ATMOSPHERIQUE DE SUBSTANCES TOXIQUES DANS LES GRANDS LACS : RESULTATS DU RMDA JUSQU'EN 1996 Resume L'objectif premier de ce document consiste a signaler les estimations biennales de charges pour le depot atmospherique des substances toxiques dans les Grands Lacs sur la periode allant de 1995 a 1996. Le depot atmospherique est le phenomene suivant lequel les substances en suspension dans 1'air sont transferees dans 1'eau, le sol ou la vegetation au niveau du sol. Dans le RMDA, on examine trois processus de depots dans les Grands Lacs: depot humide par precipitations, depot de particules seches par sedimentation et echange gazeux net de diffusion qui combine les effets de 1'absorption de 1'air a 1'eau avec volatilisation de 1'eau a 1'air. Les estimations de charges presentees ici reposent sur les mesures prises en grande partie aux stations principals du RMDA, a raison d'une de celles-ci par lac. Les substances examinees comprennent celles que suit traditionnellement le RMDA, a- et y-hexachlorocyclohexane, dieldrine,p,p '-DDE, p,p '-DDT etp,p '-DDD hexachlorure de benzene (HCB) et polychlorobiphenyles exprimes sous forme de £PCB et quatre PCB individuels : 18, 44, 52 et 101 quatre hydrocarbures aromatiques polycycliques (HAP): phenanthrene, pyrene, benzo(k)fluoranthene et benzo(a)pyrene quatre elements a 1'etat de traces : plomb, arsenic, selenium et cadmium, ainsi que d'autres signales ici pour la premiere fois, trans- et c/s-chlordane et ^raw^-nonachlore a- et |3-endosulphane et sulphate d'endosulphane une serie etendue de HAP. On a determine les charges d'une fa9on compatible avec les rapports anterieurs du RMDA, mais des ameliorations du modele comprennent une mise a jour de la base de donnees des parametres physico-chimiques utilises dans les calculs et 1'utilisation des vitesses de vent mesurees plutot qu'estimees. Par suite de ces raffmements, les charges presentees ici ne sont pas strielement comparables a celles que presentent les rapports precedents. Pour uniformiser la situation des charges du reseau dans le temps, on a recalcule les resultats pour la periode 1992-1994 et utilisant les memes hypotheses et les memes parametres de modele que pour 1995-1996. Les tendances temporelles examinees dans ce rapport reposent sur les valeurs recalculees. En examinant les charges de substances toxiques dans les Grands Lacs, on a aborde trois questions fondamentales: 1'ampleur des charges, la fa9on dont chaque element de charge contribue au total et la variation ou les tendances des charges dans le bassin et au cours de IADN Results to 1996 Page xi ------- nombreuses annees. Ces charges sont presentees sous forme de flux (masse/zone unitaire/duree unitaire; c'est-a-dire ng/m2/j), afin de tenir compte des differences entre les lacs du fait de leur zone. Les flux types des pesticides d'organochlore interdits sont d'environ 0,1 a 1 ng/m2/j et ne depassent regulierement 10 ng/m2/j que pour 1'echange gazeux de a-HCH et de dieldrine. Les flux des elements congeneres de PCB se situent en principe entre 0,1 et 1 ng/m2/j par element de charge, de fa9on analogue a bien des pesticides d'organochlore interdits, meme si les flux de volatilisation saisonniere de £PCB peuvent etre superieurs a 50 ng/m2/j. Les flux d'echange gazeux de HCB sont entre 1 et 10 ng/m2/j et les flux de pesticides d'utilisation actuelle de y- HCH et d'endosulphans se situent entre 1 et 5 ng/m2/j. L'apport de pesticides et de PCB dans les lacs est domine par 1'echange gazeux et le depot humide. Les mesures des concentrations de particules seches ont cesse apres 1995 du fait des faibles niveaux signales, mais les estimations des charges presentees ici revelent que le depot des parti cules seches de dieldrine, dep,p '-DDD et de PCB peut etre important par rapport aux autres processus de depot. La volatilisation de dieldrine et de £PCB est superieure a 1'absorption gazeuse, de sorte que les lacs servent de sources de ces substances a 1'atmosphere. Les apports de HAP et de metaux sont plus importants que ceux de pesticides et de PCB, comme on s'y attend du fait de leur emission continue dans l'environnement. Les flux de HAP se situent entre 1 a 1000 ng/m2/j suivant les especes et le processus de charge et les flux de metaux a 1'etat de traces atteignent jusqu'a 2000 ng/m2/j. Comme les metaux ne sont guere volatils, il ne subissent qu'un depot humide et sec, les flux humides etant en principe les plus importants des deux types. Les donnees disponibles signalent que la volatilisation de HAP des lacs est faible par rapport aux autres termes de flux et que 1'absorption gazeuse est substantielle pour le phenanthrene et du pyrene, alors que les HAP a poids moleculaire plus eleve sont achemines surtout par le depot des particules humides et seches. En vertu de son programme d'assurance-qualite, le RMDA a commence une nouvelle serie d'etudes d'intercomparaison entre ses organismes participants. Jusqu'a ce que les resultats soient disponibles, les comparaisons du comportement de depot entre les lacs et dans le temps se sont limitees aux situations ou les donnees ont ete engendrees par le meme organisme d'exploitation. Les flux de depot humide baissent generalement dans le temps pour les pesticides d'OC interdits, alors que les flux du depot sec et de 1'echange gazeux ont ete variables. La tendance temporelle de 1'echange gazeux s'oriente en general vers 1'equilibre air-eau. Pour les PCB, le depot humide est regulier dans le temps, alors que le depot sec s'est accru avant que les IADN Results to 1996 Page xii ------- mesures ne cessent en 1995. L'echange gazeux de PCB est dans 1'orientation de la volatilisation sur tous les lacs, mais s'approche generalement de 1'equilibre air-eau. Le depot humide et de particules seches de HAP ne revele pas de tendances nettes dans le temps, meme si les niveaux augmentent de 1'ouest a Test dans le bassin. On ne presente guere de renseignements sur les flux d'echanges gazeux nets, car les donnees de concentration en eau sont clairsemees. Le depot des metaux est limite aux depots humides et sees, les depots humides baissant dans le temps et le depot sec etant variable. Les estimations de charges etablies par le RMDA reposent traditionnellement sur 1'hypothese voulant que les stations principales situees aux stations reculees sur les lacs caracterisent le depot de fond regional. Toutefois, il est fort probable que de forts apports avec une influence geographique plus limitee existent pres de villes et de zones industrielles. Si Ton cite I'exemple de Chicago sur le lac Michigan, on constate que les donnees de 1996 ont servi a evaluer 1'effet de la pollution atmospherique des centres urbains sur les depots survenant dans les lacs. On a modifie le calcul du RMDA, en incluant une region secondaire de petit lac influenced par les fortes concentrations mesurees a Chicago et, meme si Ton doit voir dans les resultats des estimations de limite inferieure par rapport a d'autres eludes, le depot des sources de Chicago reste substantiel, d'apres les estimations, pour certains pesticides et PCB et tous les HAP. II faut d'autres travaux pour caracteriser correctement la zone lacustre touchee par la pollution de 1'air urbain et deduire des moyens efficaces d'incorporer les centres urbains aux estimations de charges du RMDA. IADN Results to 1996 Page xffi ------- Charges (kg/an) du RMDA de 1992 a 1996 Lac Superieur a-HCH Y-HCH dieldrine P.P'-DDD P.P'-DDE P,P'-DDJ HCB PCB18 PCB44 PCB52 1QQ9 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 Deoot humide 78 33 38 28 71 62 14 19 95 38 21 69 11 34 20 17 in 0.89 OS 2.6 3.8 4 4.6 2.1 6.2 59 48 1 7 32 53 25 1 9 1.5 1.2 0 92 3.1 1.6 2 34 1.4 9 1 1.7 9 9 1.9 1 1 1.8 2.1 26 2.6 Deoot sec 1 1 56 19 4.7 0 65 2.7 2.4 1.9 _ 7.4 63 25 15 _ 6 1 0.1 0.5 0 39 1.2 0.96 1.6 1 9 94 0 67 19 0 37 0 42 0 26 0 39 29 1.9 0 45 0 99 2.8 1 7 0 31 0 56 3.1 2.4 Echanae aazeux net 390 450 710 -230 -940 140 47 95 65 43 -500 -540 -500 -940 -200 _ -9.3 43 _ -18 -14 21 19 9 7.8 47 15 16 24 22 -71 -74 -71 -14 14 -19 -14 -7.3 -8 3 51 -13 -8 5 -99 34 Deoot total 470 490 760 -200 200 64 120 76 _ -470 -470 -460 -190 _ _ -7.9 _ -12 29 73 6 1 53 59 IS 26 -70 -71 -67 -10 -17 -4 -2.8 -44 -19 -56 10 -4.9 PCB101 SPCB phenan- threne pvrene B(k)F B(k)F B(k)F B(b+k)F Bfb+k~lF B(a)P Pb As Se Cd 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 Deoot humide 1 7 1.6 1 6 3.1 96 58 110 63 70 90 260 ISO 130 500 190 160 140 910 460 190 120 130 92 640 219 140 160 92 170 49 _ Deoot sec 0 45 0.74 93 1.4 27 25 86 47 _ 100 60 310 59 100 190 74 990 54 91 52 13 58 159 152 58 14 39 17 35 16000 96000 5600 2900 1SOO 3100 2100 4400 _ Echanae aazeux net -49 -39 -95 -094 99 -1300 -1200 -1000 -300 -380 -5500 -6SOO -6800 5700 2200 9SO 67 -5S 2600 910 140 20 70 190 98 22 91 35 76 34 _ Deoot total -40 -37 -91 36 -1200 -1100 -850 -180 _ -5100 -6600 -6400 6300 2500 1300 280 370 3100 490 310 160 220 990 470 220 900 170 960 120 IADN Results to 1996 Page xiv ------- Charges (kg/an) du RMDA de 1992 a 1996 Lac Michigan o^HCH Y-HCH dieldrine P.P' -ODD P.P' -DDE P.P' -DDT HCB PCB18 PCB44 PCB52 10Q9 iqq3 10Q4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Depot hiimidc 69 44 qs 56 1 S 65 190 47 96 66 58 55 62 47 30 6.4 16 1 6 1 8 3 8 1 1 3 S 74 3q 99 56 58 q7 q 96 13 1 1 1 4 0.91 091 1.3 1.6 2.6 1.7 1.4 1 9 q i 1 8 oq? 1 9 1 1 9 3 3 9 9 Depot 1 5 4 63 4 S 1 1 9 1 4 9 9 8 7.2 23 20 _ 3.8 oqs i q 048 1 4 1 4 93 69 067 038 13 0 19 035 _ 018 0.46 1.2 1.1 _ 032 067 1 4 1 1 094 055 1 4 9 Echanae 59 81 190 350 300 870 950 4qo 190 110 _ _ _ 44 35 94 1 9 -10 8 3 8.3 -69 -74 -75 -24 -24 -44 -49 -59 -90 -99 -56 -55 -60 3 9 9 Depot total 190 130 990 410 q40 370 540 990 _ _ _ 68 q? 97 97 -8 7 10 _ -68 -72 -72 -20 _ -42 -40 -49 -17 -55 -53 -56 8 PCB101 SPCB phenan- tbrene pyrene BlYlF BflflF BiVlF Bfb+k)F Rili+FiF BfalP Pb As Se Cd iqq9 iqq3 iqq4 iqqs iqq6 iqq9 iqq3 iqq4 iqqs iqq6 iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Depot hnmidc 1 4 081 1 7 9 1 1 4 59 86 71 78 48 350 230 160 360 220 220 220 130 340 140 130 110 73 480 958 170 170 77 160 84 _ _ _ _ Depot 033 066 1 1 1 6 16 94 3q 41 110 100 160 82 100 140 140 170 qs 110 56 43 63 19S 197 77 49 63 37 41 16000 _ 820 1300 _ _ 910 4500 Echanae -96 -93 -99 .q 3 _q i -1300 -1900 -1400 -330 -390 _ _ _ Depot total -94 -99 -96 -5 6 -1900 -1100 -1300 -910 _ _ _ IADN Results to 1996 Page xv ------- Charges (kg/an) du RMDA de 1992 a 1996 Lac Huron o^HCH Y-HCH dieldrine P.P' -ODD P.P' -DDE P.P' -DDT HCB PCB18 PCB44 PCB52 10Q9 iqq3 10Q4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Depot hiimidc 170 140 ISO 990 160 960 190 110 q3 13 15 19 41 1 8 3 8 67 10 3 4 qe 78 99 4 1 10 IS S X 1 1 3 3 3 6 1.3 17 4 oq4 _ 20 S 9 9 S 76 1 1 9 fi Deoot _ _ _ _ _ _ _ Echanae -SOO -4qo -SO -fi3 -34 -19 39 9q _ -760 -720 _ _ 9 S 9 S -35 -14 -IS -35 -28 -28 -29 -14 -15 -10 -10 -17 -15 -fi S -67 -73 -5 5 DeDOt total _ _ _ _ _ _ _ PCB101 SPCB phenan- threne pyrene BlYlF BflflF BiVlF Bfb+k)F ROvHrlF BfalP Pb As Se Cd iqq9 iqq3 iqq4 iqqs iqqfi iqq9 iqq3 iqq4 iqqs iqqfi iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqfi iqq9 iqq3 iqq4 iqqs iqqfi iqq9 iqq3 iqq4 iqqs iqqfi iqq9 iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Depot hnmidc 11 e i q ISO 130 no _ 640 320 250 3qo _ 350 iqo 990 350 eio 350 100000 64000 47000 15000 18000 11000 7500 6500 2200 2700 17000 19000 10000 9700 3100 6600 9qoo 9300 1400 9000 Depot _ qo 71 63 110 _ 130 77 61 130 S3 48 957 110 56 100 11000 8000 11000 7600 13000 2200 1700 1200 710 2qoo 2700 9400 9600 110 1100 470 310 410 170 310 Echanae 077 074 -77 -6 1 -4qo -460 -940 -930 _ _ _ Depot total _ 1 1 0000 79000 58000 93000 31000 13000 q20o 7700 2qoo 5600 20000 14000 13000 9SOO 4900 7100 3900 9700 1600 9300 IADN Results to 1996 Pagexvi ------- Charges (kg/an) du RMDA de 1992 a 1996 Lac Erie o^HCH Y-HCH dieldrine P.P' -ODD P.P' -DDE P.P' -DDT HCB PCB18 PCB44 PCB52 10Q9 iqq3 10Q4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq? iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Depot hiimidc 84 35 iq 9q 63 46 93 99 13 1 7 28 32 sq 12 9.4 1.9 3.4 1 4 1 7 9 46 46 3 6 7 8 96 34 qs 1 5 14 4q oss S4 04 073 0.34 034 0.57 056 1.4 0.43 055 081 1 6 oqe 039 049 0 79q 1 1 7 Ofi5 Depot 1 9 9 34 oq 045 1 3 OS3 06 56 3.7 18 11 _ 2 0.21 1 9 053 065 1 9 43 9 1 1 5 09 64 091 099 _ 0.12 0.21 0.74 06 _ 023 043 083 1 9 098 033 085 1 3 Echanae 140 9qo 300 190 44 60 S3 68 45 47 -300 -120 -110 -110 -110 _ 90 30 14 -17 076 -7 -1 -5.7 -17 -15 -15 -22 -26 -54 -1 1 -5 9 -11 -16 -5 8 9 9 -5 9 -8 6 -13 DeDOt total 930 330 390 150 110 110 91 sq -270 -84 -83 -87 _ _ 58 130 -16 13 -64 -005 _ -17 -14 -14 -20 _ -46 0 14 -9 8 -8 8 -5 1 -1 1 -3 4 -56 PCB101 SPCB phenan- threne pyrene BlYlF BflflF BiVlF Bfb+k)F Rili+FiF BfalP Pb As Se Cd iqq9 iqq3 iqq4 iqqs iqq6 iqq9 iqq3 iqq4 iqqs iqq6 iqq2 iqqs iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe iqq2 iqqs iqq4 iqqs iqqe iqq2 iqq3 iqq4 iqqs iqqe iqq9 iqq3 iqq4 iqqs iqqe Depot hnmidc 048 081 1 1 1 4 051 91 96 41 58 18 500 360 210 530 91 330 310 160 360 58 150 140 81 560 158 180 iqo q7 iqo 50 _ _ _ _ Depot 098 037 073 1 4 16 14 9q ^9 86 100 190 160 190 110 130 950 910 960 60 84 100 580 430 63 57 qs 100 190 13000 13000 _ 1500 1400 _ _ 9800 9400 1 100 1500 Echanae -9 9 1 -96 -5 9 -66 -900 -100 -900 -990 -310 1600 -770 9qo -SO 59 15 -075 -8 _ _ Depot total -1 4 9 9 -077 -9 4 -160 -60 -130 -130 2300 -4qo S60 940 1900 600 9qo 160 _ _ IADN Results to 1996 Pagexvii ------- Charges (kg/an) du RMDA de 1992 a 1996 Lac Ontario a-HCH Y-HCH dieldrine P.P' -ODD P.P' -DDE P.P' -DDT HCB PCB18 PCB44 PCB52 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 Deoot humide 52 39 33 21 31 50 37 24 13 96 11 54 ^ 39 4.5 9 9 036 049 049 059 4.4 2 061 53 2 33 79 1.1 14 4 1 6.1 3 069 073 087 9 5 098 035 081 071 3.6 5.7 066 9 1.4 1.6 1 4 093 2.5 9 5 Deoot sec _ _ _ _ _ _ _ _ _ _ _ _ _ Echanae aazeux net -80 -54 -93 -5.7 -1 1 -89 -1.5 7.9 19 17 -330 -900 -180 -230 -210 _ -96 -99 -SO 44 S 5 8.2 _ -170 -190 -150 39 -28 -19 99 -19 -18 -16 -19 -21 -IS -90 -19 -18 99 -18 -11 -9 5 Deoot total _ _ _ _ _ _ _ _ _ _ _ _ _ PCB101 SPCB phenan- threne B(k)F B(k)F BfkW B(b+k)F B(b+k)F Bfa~lP Pb As Se Cd 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1999 1993 1994 1995 1996 1992 1993 1994 1995 1996 1992 1993 1994 1995 1996 Deoot humide 1.7 9 3 069 1.8 1 3 56 89 15 38 96 70 540 380 110 250 64 470 220 130 960 33 173 311 54 _ 63 110 40000 27000 15000 7600 5000 9900 3100 2100 970 580 5500 5000 3900 1300 1100 2600 1300 550 530 390 Deoot sec 41 95 44 28 63 88 55 48 46 83 92 79 99 105 249 86 79 43 29 60 4500 5300 6100 3300 5100 570 790 630 210 610 1000 1600 1800 150 340 96 99 130 49 100 Echanae aazeux net -1.6 -94 -0 84 -62 -54 -450 -570 -450 -930 -930 -510 _ -46 -9.7 _ _ Deoot total -400 _ 110 120 45000 32000 91000 11000 10000 3500 3800 2700 1200 1900 6500 6600 5700 1500 1400 2700 1400 680 580 490 IADN Results to 1996 Pagexviii ------- IADN Results to 1996 Page xix ------- IADN Results to 1996 Page xx ------- Table of Contents Map of the IADN Network i Executive Summary iii Resume xi 1. Introduction 1 2. Methods 1 2.1 Substances Considered 2 2.2 Calculation of Mass Flux and Corresponding Lake-wide Loading 2 2.3 Model Refinements for 1995-96 3 2.4 Sources of Data 3 3. Results and Discussion 5 3.1 Master Station Loadings for 1995 and 1996 5 3.1.1 Banned Organochlorine Pesticides 7 3.1.2 Current-use Pesticides 7 3.1.3 Banned Organochlorine Commercial Chemicals 8 3.1.4 Currently-Emitted PAHs and Metals 8 3.2 Expanding Spatial Information beyond IADN Master Stations 9 3.3 Temporal and Spatial Trends in Master Station Loadings 9 3.3.1 Organochlorine Pesticides 11 3.3.2 PCBs 11 3.3.3 PAHs 12 3.3.4 Metals 12 3.4 Applicability of IADN Method to Estimating Urban Impacts: Case of Chicago 13 4. Conclusions 19 Acknowledgements 21 References 23 Appendix A: Derivation of Simplified Mass Transfer Coefficients 27 Appendix B: Selected Data Used in Calculating IADN Loadings 3 3 Appendix C: IADN Mass Loadings for 1995 and 1996 37 Appendix D: Relative Loadings of IADN Substances 69 Appendix E: Variation in Precipitation and Air Concentration within Lake Basins for 1996 81 Appendix F: Annual Mass Fluxes to the Great Lakes form 1992 to 1996 87 IADN Results to 1996 Page xxi ------- List of Tables Table 1: Henry' s Law Constants used in IADN Calculation of Gas Exchange 4 Table 2: Mass Fluxes (ng/m2/d) of Atmospheric Deposition at Sleeping Bear Dunes 14 Master Station (SBD) and Chicago Table 3: Lakewide Loadings to Lake Michigan: Effect of Adding Loadings from Chicago 17 to Master Station Estimates of Regional Background (BG) Loadings Table 4: Comparison of Additional Loading to Lake Michigan (kg/yr) due to Air from 18 Chicago as Calculated by IADN and Other Studies Table B1: Summary of Meteorological Data at IADN Master Stations, 1992-1996 35 Table B2: Lake Water Concentrations for IADN Loadings Estimates of 1995-96 36 Table Cl: Atmospheric Fluxes to Lake Superior for 1995 39 Table C2: Atmospheric Fluxes to Lake Superior for 1996 42 Table C3: Atmospheric Fluxes to Lake Michigan for 1995 45 Table C4: Atmospheric Fluxes to Lake Michigan for 1996 48 Table C5: Atmospheric Fluxes to Lake Huron for 1995 51 Table C6: Atmospheric Fluxes to Lake Huron for 1996 54 Table C7: Atmospheric Fluxes to Lake Erie for 1995 57 Table C8: Atmospheric Fluxes to Lake Erie for 1996 60 Table C9: Atmospheric Fluxes to Lake Ontario for 1995 63 Table CIO: Atmospheric Fluxes to Lake Ontario for 1996 66 Table El: 1996 Annual Volume-Weighted Mean Pesticide Concentrations in 83 Precipitation (ng/L) Table E2: 1996 Annual Volume-Weighted Mean HCB, PCB and PAH Concentrations 84 in Precipitation (ng/L) Table E3: 1996 Annual Pesticide Concentrations in Air (pg/m3) 85 Table E4: 1996 Annual HCB and PCB Concentrations in Air (pg/m3) 85 Table E5: 1996 Annual PAH Concentrations in Air (pg/m3) 86 IADN Results to 1996 Page xxii ------- List of Figures Figure D1: Loadings as a Proportion of Total Deposition to Lake Superior in 1995 71 Figure D2: Loadings as a Proportion of Total Deposition to Lake Superior in 1996 72 Figure D3: Loadings as a Proportion of Total Deposition to Lake Michigan in 1995 73 Figure D4: Loadings as a Proportion of Total Deposition to Lake Michigan in 1996 74 Figure D5: Loadings as a Proportion of Total Deposition to Lake Huron in 1995 75 Figure D6: Loadings as a Proportion of Total Deposition to Lake Huron in 1996 76 Figure D7: Loadings as a Proportion of Total Deposition to Lake Erie in 1995 77 Figure D8: Loadings as a Proportion of Total Deposition to Lake Erie in 1996 78 Figure D9: Loadings as a Proportion of Total Deposition to Lake Ontario in 1995 79 Figure D10: Loadings as a Proportion of Total Deposition to Lake Ontario in 1996 80 Figure F1: Annual Average Wet Deposition Flux (ng/m2/d) of Organochlorine Pesticides 89 Figure F2: Annual Average Dry Deposition Flux (ng/m2/d) of Organochlorine Pesticides 90 Figure F3: Annual Average Net Gas Exchange Flux (ng/m2/d) of Organochlorine 91 Pesticides Figure F4: Annual Average Wet Deposition Flux (ng/m2/d) of PCBs 92 Figure F5: Annual Average Dry Deposition Flux (ng/m2/d) of PCBs 93 Figure F6: Annual Average Net Gas Exchange Flux (ng/m2/d) of PCBs 94 Figure F7: Annual Average Wet Deposition Flux (ng/m2/d) of PAHs 95 Figure F8: Annual Average Dry Deposition Flux (ng/m2/d) of PAHs 96 Figure F9: Annual Average Net Gas Exchange (ng/m2/d) of PAHs 97 Figure F10: Annual Average Wet Deposition Flux (ng/m2/d) of Metal s 98 Figure F11: Annual Average Dry Deposition Flux (ng/m2/d) of Metals 99 IADN Results to 1996 Page xxiii ------- IADN Results to 1996 Page xxiv ------- 1. Introduction In response to growing concerns on the part of the International Joint Commission, a workshop investigating the role of atmospheric deposition in the delivery of toxic substances to the Great Lakes was held in Scarborough, Ontario, Canada in 1986. That workshop culminated in two major products: the first-ever collection of data and consequent development of loading estimates to the Lakes based on data from the 1980-1985 period (Strachan and Eisenreich, 1988) and the development of "The Plan" (Voldner and Eisenreich, 1987) aimed at improving those estimates in the future. Four years after that first report, an update to the loadings was prepared (Eisenreich and Strachan, 1992) in which many of the needed improvements called for in "The Plan" were implemented. Although IADN in its current form was taking shape, mass loading estimates were still available only for wet and dry particle deposition, with gas-particle partitioning in air determined by ascribing a temperature-dependent partitioning factor after the Junge-Pankow model (Junge, 1977; Pankow, 1987) rather than direct measurement. In 1996, the first set of loading estimates including gas exchange and using measured values of gas and particle-phase concentrations in air was published. (Hoff et al., 1996) This was followed by the first formal biennial loadings report for the period 1993-1994. (Ffillery et al., 1998) The current report builds on these efforts and delivers results for data collected in 1995 and 1996. The biennial reporting schedule for IADN is mandated by Annex 15 of the Canada-U.S. Great Lakes Water Quality Agreement. That annex describes two activities relating to airborne toxic substances: monitoring and surveillance for the estimation of loadings to the lakes, and research into atmospheric processes and sources of contaminants responsible for those loadings. These two activities are conducted separately even though some scientists and managers are involved in both. The present report addresses only the monitoring and surveillance component of Annex 15 and presents the scientific details of lADN's atmospheric loading estimates for 1995-96. Since pathways other than atmospheric deposition contribute to the entry of toxic substances to the lakes, the loadings estimates reported through IADN provide only part of the information needed to develop a complete understanding of toxic substances in the Great Lakes basin. 2. Methods Loading estimates are calculated as the sum of three process-related terms: wet deposition, dry particle deposition, and net gas exchange. The latter is defined as the sum of an absorption term (from air to water, defined herein as positive gas exchange) and a volatilisation term (from water to air, defined herein as negative gas exchange). Each loading term is determined on an average seasonal basis after regular measurements of the various parameters of interest. An estimate of the variability associated with that average is also made. IADN Results to 1996 Page 1 ------- 2.1: Substances Considered Loadings results have traditionally been reported through IADN for 20 substances. These are a- and y-hexachlorocyclohexane, dieldrin,/?,/? '-DDE, p,p '-DDT, andp,p '-ODD, HCB, four PCBs: 18, 44, 52 and 101, as well as £PCB as estimated by each analytical laboratory, 4 PAHs: phenanthrene, pyrene, benzo(k)fluoranthene, and benzo(a)pyrene, and 4 trace elements: lead, arsenic, selenium and cadmium. The 1995-96 results reported here include those 20 substances and, in addition, loadings of trans- and c/'s-chlordane, rram--nonachlor, a- and |3- endosulphan, endosulphan sulphate and an expanded suite of PAHs. The PAHs are those suggested for reporting under the UN ECE LRTAP Convention's 1998 Aarhus Protocol on Persistent Organic Pollutants: benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, and indeno(l,2,3-cd)pyrene. (UN ECE, 1998) A modified suite of PCBs is also under development within IADN. This class of substances has presented a particular challenge to the network due to methodology differences between participating laboratories that result in variations in the individual PCBs reported and, consequently, the sum of PCBs calculated. The resulting suite is being designed to meet two criteria: (a) individual congeners in the suite are to be detected the majority of the time at the majority of sites, (b) the resulting £PCB is to represent a significant fraction of the calculated total of all measured congeners. At the time of writing, an initial suite of approximately 60 congeners is being tested for consistency across lakes and sampled media. 2.2: Calculation of Mass Flux and Corresponding Lake-wide Loading The calculation method for IADN loadings has been described in detail elsewhere (Hoff 1994, Hoff et al. 1996, Hillery et al., 1998) and is only summarized here. The wet deposition estimate is the most straightforward, with the mass flux being the product of the volume-weighted mean concentration of the substance of interest in precipitation and the rate of precipitation. The dry deposition estimate is obtained by multiplying the concentration of the substance of interest associated with airborne particles by an assumed deposition velocity. The use of this constant deposition velocity is estimated to incorporate substantial error (Hoff, 1994), but available information on dry deposition has not yet been translated into an improved method for use in the network. Finally, the net gas exchange is calculated as the product of the mass transfer velocity and the concentration gradient between air and water as scaled by Henry's Law. The gas exchange component of the total loading is estimated by use of a model describing diffusive transfer through thin films forming the interface between the bulk liquid of the lake water and the overlying air. (Schwarzenbach et al., 1993) Mass transfer coefficients (inverse resistances to transfer) are determined by taking established relationships for wind speed- dependent mass transfer of CC>2 to quantify the resistance in the water phase and H2O to quantify the resistance in the vapour phase (Hornbuckle, 1994), and adjusting for differences in IADN Results to 1996 Page 2 ------- diffusivities between the sample substance (CC>2 or H20) and the toxic chemical of interest. In preparing the latest round of IADN results, and consequently updating the computer programs used in the calculations, it was seen that the methods used to determine those dimensionless multipliers can be significantly simplified compared to previously reported calculations of the same nature. The simplifications are presented in Appendix A. 2.3: Model Refinements for 1995-96 Three refinements were made to the IADN model for the calculation of results for 1995-96. Because of these changes, the Master Station loadings presented in the remainder of this report are not directly comparable to previously published results. An analysis of mass loadings over several years is presented in Section 3.2 and includes revised loadings for previous years calculated by the model as modified for 1995-96. The first modification made was an update to the database of Henry's Law constants used in the calculation of gas exchange and, in particular, inclusion of recently determined temperature- dependent estimates. The values used are listed in Table 1. H values were also updated for many PCB congeners in anticipation of the newly defined PCB suite. However, since the suite is still under development, these 1995-96 results use physico- chemical parameters for £PCB from previous calculations. The second change made to the model was to use measured wind speeds in determining the gas exchange term of the fluxes rather than the constant wind speed of 5 m/s that was used in previous calculations. For 1995-96, those varied from 3 m/s to 5 m/s on an annual average basis. Such a variation has a significant effect on mass transfer estimates. For example, at 15°C and using the Henry's Law constants shown in Table 1 above, reducing the wind speed from 5 m/s to 3 m/s results in decreases in overall mass transfer coefficient for gas exchange with respect to water, koL, of 31% for B(k)F and 60% for PCB 101. The final change made is a typographic correction to the coding involved in calculating the air- side mass transfer coefficient, ka That correction increases ka by approximately 12% relative to previously published IADN values for all substances regardless of environmental conditions. 2.4: Sources of Data Concentration data for the vapour and particle fractions of air were obtained from measurements made every 12 days at each of the IADN Master Stations. At the Lake Huron and Ontario sites, each sample draws approximately 350 m3 over 24 hours and at the Lake Superior, Michigan and Erie sites, 815m3 of air are sampled over the same time period. IADN Results to 1996 Page 3 ------- Table 1: Henry's Law Constants used in IADN Calculation of Gas Exchange Substance a-HCH dieldrin c/'s-chlordane trans-chlordane trans-nonachlor p,p '-ODD p,p '-DDE p,p '-DDT y-HCH a-endosulphan |3-endosulphan HCB PCB 18(tri) PCB 44 (tetra) PCB 52 (tetra) PCB 101 (penta) phenanthrene pyrene benzo[b]fluoranthene benzo[k]fluoranthene benzo[a]pyrene indeno[l,2,3- cd] pyrene Parameters m and b for Henry's Law Constant, H (Pa-m3/mol), logw H = m/T+b m -3054 -3416 -3416 -3416 -3416 -3416 -3416 -3416 -2694 -876 -3416 -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 0.446 8.18 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) Suntioetal. (1987); Tateya et al. , (1988); as perHoSetal. (1996) Iwataetal. (1995) Cotham and Bidleman (1991) Cotham and Bidleman (1991); Jantunen and Bidleman (2000) Rice etal. (1997) Rice etal. (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) Bamfordetal. (1999) Bamfordetal. (1999) Ten Hulscher et al. (1992) Ten Hulscher et al. (1992) Ten Hulscher et al. (1992) Ten Hulscher et al. (1992) IADN Results to 1996 Page 4 ------- Whole precipitation concentrations were determined at all Master Stations. Composite samples were collected every 14 days for Lake Huron and every 28 days at the other Master Stations. Many of the meteorological data necessary to the determination of mass flux were collected on- site. Seasonal and annual statistics for wind speed and precipitation were computed for the entire season or year in question rather than the times when samplers were operating. Lake water surface temperatures, assumed to equal the temperature of the air film involved in air- water exchange, were obtained from the National Oceanic Atmospheric Administration's (NOAA) Great Lakes Environmental Research Laboratory (GLERL) satellite data. (NOAA, 1999) Annual meteorological data are presented in Table Bl of Appendix B. All air and precipitation concentrations and meteorological data from IADN sites were submitted to quality control through the Research Data Management and Quality Control System (Sukloff et al., 1995) administered at the Centre for Atmospheric Research Experiments of Environment Canada. Lake water concentrations are not measured directly in IADN. Rather, available data were pooled from cruises taken over recent years. Cruise data were available from the US R/V Lake Guardian cruise of the five lakes in spring 1996 as well as from CCGV Limnos cruises of Lakes Superior (1996), Erie (1995) and Ontario (1998). Some samples on the Limnos cruises were collected and analysed by two different agencies of Environment Canada: the National Water Research Institute and the Ecosystem Health Division of Ontario Region with some overlap of analytes. If more than one data source was available, pooling of concentration data was performed by weighting inversely by variance to account for different sample sizes and precisions. (Taylor, 1990) Final values are compiled in Table B2 of Appendix B. It is evident that lake concentration data useful to IADN loading estimates are sparse, and this problem has been identified in previous loading reports as well. (Hoff et al., 1996; Hillery et al., 1998) Where no values are available, no estimate of the volatilisation from lake water to air can be made. This is a serious detriment to the production of loading estimates since volatilisation is a significant process in the atmospheric cycling of most of these substances. 3. Results and Discussion 3.1: Master Station Loadings for 1995 and 1996 In examining the loadings of toxic substances to the Great Lakes, three fundamental issues are considered: the magnitude of the loadings, the manner in which each loading component contributes to the total, and the variation or trends in the loadings across the basin and over many years. The first two issues are considered in this section, and spatial and temporal trends are discussed separately in Section 3.3. IADN Results to 1996 Page 5 ------- Although previous IADN reports have reported lakewide loadings (kg/yr), the following discussion is based on mass fluxes (ng/m2/d) so that direct between-lake comparisons of the deposition can be conducted. To obtain the lakewide loading, the flux can simply be multiplied by the appropriate lake area and the resulting units converted from ng/d to kg/yr. The lake areas are 82,100 km2, 57,800 km2, 59,600 km2, 25,700 km2 and 18,960 km2 for Lakes Superior, Michigan, Huron, Erie and Ontario, respectively As a result, the annual loading in kg/yr can be obtained by multiplying the annual mass flux in ng/m2/d by 30, 21, 22, 9.4 or 6.9. Atmospheric loadings to the five Master Stations for 1995 and 1996 are presented in Appendix C in Tables Cl to CIO. Each table is divided into 4 sub-tables (a-d) by chemical group: banned organochlorine pesticides, current-use pesticides, banned organochlorine commercial chemicals, and currently-emitted PAHs and metals. The measured concentrations in air and precipitation exhibit marked variation over the annual cycle. As such, it is important to determine if the reported atmospheric loadings are likely different from zero. To do so, each loading term is assigned a coefficient of variation (COV) following the error propagation analysis conducted by Hoff (1994). Then, assuming the data are normally distributed, dry deposition and gas exchange loadings are said to be significantly different from zero if the reported COV is less than 267% for annual values and less than 120% for seasonal values. This result is based on a 95% confidence interval for annual sample sizes of 30 and seasonal sample sizes of 8. For wet deposition on Lake Huron, where samples are collected every 14 days, loadings are different from zero if the COV is less than 108% on a seasonal basis or 248% on an annual basis. For the other lakes, wet deposition is significantly different from zero if the COV is less than 40% on a seasonal basis or 165% annually. A series of graphs depicting the relative magnitude of each loading component as fraction of the total input to the lake is presented in Appendix D. The total inputs in these graphs are normalized to 100% and represent the total "downward" loading from air to water. Gas exchange graphs include a negative component representing "upward" loading through volatilisation. The magnitude of the volatilisation term is expressed as a fraction of the net downward loading. If a negative loading component is greater than 100%, the lake under discussion is subject to net loss of contaminant to the atmosphere and is thus behaving as a contaminant source. The amount of information generated by IADN is large. For example, 290 mass fluxes are presented for each lake each year in Appendix C alone. Since this document is aimed at reporting rather than exhaustive analysis, the following discussion will present a general overview of results and point out interesting features in the data. The loading values themselves are presented in the appendices for readers wanting a greater degree of detail. IADN Results to 1996 Page 6 ------- 3.1.1: Banned Organochlorine Pesticides Typical values for annual fluxes of banned organochlorine pesticides are on the order of 0.1 to 1 ng/m2/d and only regularly exceed 10 ng/m2/d for gas exchange of a-HCH and dieldrin. The inputs are dominated by gas exchange on Lakes Superior and Ontario whereas wet deposition plays a significant role on the other lakes, particularly Lake Huron where wet deposition dominates delivery. For this group of substances, water data are available on all lakes only for a-HCH and cis- and trans-chlordane. In general, a-HCH and c/s-chlordane are close to air- water equilibrium in Lakes Superior and Ontario while the other lakes are net recipients of these banned substances. The behaviour of rram--chlordane is the most variable of this class of substances across the basin. In Lakes Superior and Michigan, levels are such that the water is a net recipient, but the balance is not far from air-water equilibrium. In Lake Ontario, the opposite is true, with volatilisation being about twice the net inputs. Lake Erie shows a net input situation but, unlike Lakes Superior and Michigan, it is far from air-water equilibrium. No rram--chlordane data are available for Lake Huron for either wet or dry particle deposition, but gas exchange shows about 2 times more volatilisation than absorption. Dieldrin undergoes net volatilisation in all lakes for which water data exists, with outputs ranging from 3 to 4 times net inputs for Lakes Superior and Erie and more than 10 times net inputs for Lake Ontario. Inputs of dieldrin consist of a significant wet deposition component on all lakes. Except for Lake Superior, which was monitored during CCGV Limnos cruises, p,p '-DDT and its metabolites, p,p '-ODD andp,p '-DDE, can only be assessed on the input side since the available lake water data from the Lake Guardian cruises were judged unreliable by the originating lab. In general, inputs of the DDTs are comprised of significant fractions of wet deposition, dry particle deposition and gas absorption. It is interesting to note that ODD has a substantial contribution by dry particles for Lakes Superior, Michigan and Erie in 1995. This cannot be assessed on other lakes or years due to a network-wide decision to abandon particle-phase analysis of air samples for the banned organochlorines. This decision may warrant re-evaluation given results presented here for dieldrin, ODD and PCBs (see subsequent section on banned organochlorine commercial chemicals). 3.1.2: Current-use Pesticides lADN's list of current-use pesticides is limited to y-HCH and endosulphan. Daily fluxes of these pesticides are of the order of 1 to 5 ng/m2/d. Lake water data are available for y-HCH which, in all cases, is still being delivered to the lakes at a rate greater than its removal by volatilisation. That input is largely driven by gas absorption although wet deposition is important IADN Results to 1996 Page 7 ------- on Lake Ontario and even more so on Lake Huron, a-endosulphan is similar to y-HCH in that its delivery to the lakes is dominated by gas absorption. Wet and dry deposition are more important in delivering p-endosulphan and endosulphan sulphate to the lakes than they are for a-endosulphan. 3.1.3: Banned Organochlorine Commercial Chemicals This class of compounds includes hexachlorobenzene (HCB) and the poly chlorinated biphenyls (PCBs). Average daily fluxes for individual reported PCB congeners are of the same order of magnitude as the banned organochlorine pesticides and fall between 0.1 and 1 ng/m2/d for each loading component. HCB in the gas phase tends to fall in the 1 to 10 ng/m2/d range and seasonal £PCB can be higher than 50 ng/m2/d, albeit in the volatilisation direction. In general, it is the gas-phase processes of absorption and volatilisation that are dominating the atmospheric delivery of these substances to the lakes although wet deposition plays an important role on Lakes Michigan and Ontario. With the exception of Lake Superior, large volatilisation terms are leading to a net loss of PCBs from the lakes. HCB is close to air-water equilibrium in the lakes except Lakes Huron and Ontario where volatilisation is occurring. As was the case for the banned organochlorine pesticides, PCB analysis of airborne particles ceased after 1995 for Lakes Superior, Michigan and Erie, and had ceased even earlier on Lakes Huron and Ontario. An examination of the PCB data presented for 1995 on Lakes Superior, Michigan and Erie shows that, even though particle-bound PCB concentrations may be low, the contribution made by dry deposition can be significant at 8% to 21% of the total downward loading. 3.1.4: Currently-Emitted PAHs and Metals These substances are treated together because of their continued emission to the atmosphere in the Great Lakes region from a variety of industrial, transportation and residential sources. Mass fluxes of PAHs are variable with values in the 1 -100 ng/m2/d range except for phenanthrene which exhibits gas exchange terms typically in the 100 -1000 ng/m2/d range. Lake water data were available for Lakes Superior and Erie and volatilisation is small there compared to net downward fluxes. Inputs of phenanthrene are dominated by gas absorption and pyrene is more evenly split between the downward deposition modes. The heavier PAHs are delivered mostly by wet and dry particle deposition. Metals are measured only on Lakes Huron and Ontario. Fluxes of these substances are larger than those of most of the other substances in this report with values in the 100 ng/m2/d range for As, Se and Cd and close to 2000 ng/m2/d for Pb. Being relatively non-volatile, the atmospheric deposition of these substances is limited to wet and dry particle deposition with the former generally contributing more than half of the total downward flux. IADN Results to 1996 Page 8 ------- 3.2: Expanding Spatial Information beyond IADN Master Stations The preceding results described mass fluxes based on measurements taken at one Master Station per lake. However, participating agencies operate other sites in the Great Lakes that are considered satellite stations in IADN. As a step toward exploring the spatial variation within lake basins as an indication of the representativeness of the Master Stations, annual average concentrations of some IADN chemicals measured at satellite stations were compared as presented in Appendix E. Annual volume-weighted mean precipitation concentrations for 1996 are presented in Tables El and E2. There is good agreement between average annual concentrations measured on the same lake for sites operated by the same agency(all-substance average relative standard deviations of 21% to 54% depending on the lake in question) except for the large difference in concentrations measured on Lake Michigan as expected due to the urban location of the Chicago site. Agreement within a given lake basin declines when results from different agencies are compared; relative standard deviations of same-lake measurements by all agencies are 10% to 39% higher (RSD units) than those taken by only one agency. Air measurements are compared in Tables E3, E4 and E5. Only Lake Superior has multiple sites operated by the same agency. As with precipitation, those within-agency results show good comparability with an all-substance average RSD of 32%. Unfortunately, it is not possible to conduct an inter-agency analysis to compare to the intra-agency result since no two agencies are measuring air the same way on any given lake. In order to proceed with estimating the spatial variation within the lake basins, it is first necessary to quantify and adjust the differences that exist between the agencies in their measurements. With this goal, IADN is enhancing its quality assurance activities with a renewed set of field audits and laboratory intercomparisons already underway. Additionally, Indiana University is hosting a meeting of the IADN precipitation analytical chemists to review analytical protocols with the goal of harmonizing methodologies. Finally, all agencies involved in IADN are presently engaged in a side-by-side intercomparison study at Point Petre to estimate total (sampling and analytical) variability among agencies. 3.3: Temporal and Spatial Trends in Master Station Loadings Over recent years, scientists associated with IADN have conducted several studies examining the manner in which toxic substance concentrations in air and precipitation are changing with time. (Hillery et al., 1997; Cortes et al., 1998; Simcik et al, 1999; Cortes et al., 1999; Cortes et al., 2000; Simcik et al., 2000) Those studies have shown that the rates at which concentrations are decreasing are generally consistent between the atmospheric compartments and other media such as lake water and biota. Furthermore, a variety of techniques has IADN Results to 1996 Page 9 ------- successfully been applied to discriminate between continued local emission of a substance and its presence in the Great Lakes atmosphere through regional background or long-range transport. (Hoffet al, 1998; Cortes et al., 1999) lADN's formal mandate goes beyond the characterisation of trends in atmospheric concentrations to the determination of trends in loadings to the lakes. The distinction arises from the fact that the exposure pathway for these contaminants is primarily through the aquatic food chain. Previous IADN reports have included estimates of changes in loadings to the lakes, (Eisenreich and Strachan, 1992; Hoffet al., 1996; Hillery et al., 1998) although interannual variability has been difficult to quantify with certainty. Uniform quality control of IADN data and incorporation in a common database have only recently been achieved. As a result, it is possible for the first time to report results determined with consistent treatment of the data collected over the five years from 1992 to 1996 at all sites. Full results for the substances reported consistently since 1992 are presented in Appendix F with points of interest discussed in Sections 3.3.1-3.3.4. Wet deposition and dry particle deposition can change in magnitude with time, but gas exchange can also change direction from net absorption to net volatilisation or vice versa. Since uncertainties in gas exchange can be particularly large near equilibrium, the fugacity ratio has been considered when describing temporal trends in gas exchange. As described by Mackay (1991), fugacity is a measure of the tendency of a substance to escape from the phase in which it resides; phases in equilibrium with each other have equal fugacities. Applying this concept to gas exchange leads to a fugacity ratio of unity being the descriptor of equilibrium between absorption and volatilisation. The ratio of gas exchange mass fluxes calculated by IADN is equivalent to the ratio of fugacities because the mass transfer coefficient is the same for the diffusive transport in both directions. All fugacity ratios are reported for air divided by water and are presented as fRyear (e.g. fugacity ratio in 1995 = fRi995). A ratio greater than one indicates net absorption by the water and a ratio less than one indicates net volatilisation from the water to the air. As a result of the lack of agreement between measurements conducted by different agencies operating sites on the same lake (see Section 3.2), results from Master Stations operated by different agencies on different lakes cannot be compared directly with confidence. As a result, comparisons in space and time should only be made for measurements made by the same agency. Air and precipitation measurements made on Lakes Superior, Michigan and Erie are comparable in space, but a change of analytical laboratory in 1994 makes results comparable in time over two distinct periods: from 1992-1994 and 1995-1996. Air measurements made on Lakes Huron and Ontario are comparable in space and over the entire period from 1992- 1996. Over 1992-1994, precipitation measurements on Lakes Huron and Ontario were made IADN Results to 1996 Page 10 ------- by the same agency but a change occurred on Lake Huron in 1995. Therefore, results are fully comparable between the two lakes only from 1992-1994. 3.3.1: Organochlorine Pesticides Annual wet deposition fluxes are generally decreasing in time for the OC pesticides, including lindane at sites in Canada where it is still used. The exceptions to this trend are dieldrin and the p,p '-DDT group whose wet deposition is increasing on Lake Huron. For the comparable sites at Lakes Superior, Michigan and Erie, wet deposition fluxes of the HCHs are lower at Lake Superior than at the other two lakes. Information needed for the estimation of dry deposition fluxes of OC pesticides is only available on Lakes Superior, Michigan and Erie. At these sites, the airborne particle phase ceased to be analysed for OCs in 1995. Dry deposition fluxes of the HCHs are similar for all three lakes. Dieldrin values increase from west to east by a factor of 2. p,p '-DDD, p,p '-DDE andp,p '- DDT fluxes are only available for 1992 and 1995; they are similar on Lakes Superior and Michigan and higher on Lake Erie. A temporal comparison of these fluxes cannot be made since measurements were made by different agencies. Gas exchange fluxes of OC pesticides are variable across the basin. This is reasonable given the complexity inherent in a flux term driven by the gradient between concentrations in air and lake water. In general, the temporal trend is toward air-water equilibrium although some substances appear to have reversed from one direction of air-water exchange to the other over 1992-1996. For example, y-HCH on Lakes Huron (fRi992 not available, fRi993 = 0.69, fRi996 = 1.94) and Ontario (fRi992 = 0.82, fRi996 = 1.89) is now in net absorption. The gas exchange of dieldrin is in the direction of volatilisation for all lakes. 3.3.2: PCBs Four congeners of PCBs are investigated (trichlorinated PCB18, tetrachlorinated PCB44 and PCB52, and pentachlorinated PCB101) in IADN as well as IPCB, and the behaviours of all five PCB parameters are generally similar to each other. In wet deposition, the change in time is not steady except on Lake Huron, where fluxes decreased decisively until 1994 when the last PCB precipitation measurements were taken there. Wet deposition fluxes of £PCB are similar at the spatially comparable sites on Lakes Superior, Michigan and Erie. Depositional fluxes for dry particle PCBs are available only for Lakes Superior, Michigan and Erie up to 1995. Particle deposition to these lakes generally increased from 1992-94, the period over which the same laboratory was analysing samples at those sites. Over all years, flux values are similar on Lakes Superior and Michigan and are approximately 50% higher on Lake Erie. IADN Results to 1996 Page 11 ------- Gas exchange of £PCB is in the volatilisation direction on all lakes but approaching air-water equilibrium everywhere but Lake Erie, where the rate of volatilisation is steady and may be increasing. Individual congeners are generally behaving in a fashion similar to £PCB over time. The 4IADN congeners appear to have reversed from volatilisation to absorption on Lake Superior as has PCB52 on Lake Michigan, but the apparent reversal takes place at the time of laboratory changeover on those lakes. PCB101 has reversed from absorption to volatilisation on Lakes Huron and Ontario (e.g. Ontario: fRi992 = 1.3, fRi996 = 0.52) although net flux values are small and therefore highly uncertain. 3.3.3: PAHs Wet deposition of PAHs shows no consistent trends over the five years presented in Appendix F, and this is compatible with the fact that they continue to be emitted unlike other IADN substances that have been banned. Levels increase from west to east when looking at spatially comparable data for Lakes Superior, Michigan and Erie and for Lakes Huron and Ontario. Wet deposition is generally greater for phenanthrene and pyrene than it is for benzo(k)fluoranthene and benzo(a)pyrene, with the difference increasing from west to east. The dry deposition of PAHs appears steady in time for same-agency time periods on Lakes Superior, Michigan and Huron. As with wet deposition, fluxes tend to increase from west to east across the basin. Dry deposition fluxes on Lake Erie are up to 5 times greater than those on Lake Superior. Little gas exchange flux information is presented since water concentration data were available only on Lake Superior and Lake Erie, with Lake Superior being the only lake with 5 years of gas exchange flux estimates. The change in direction of gas exchange is different on the two lakes, with Lake Superior switching from volatilisation to absorption at the same time as the change in analytical laboratory for that site while Lake Erie phenanthrene gas exchange reversed from absorption to volatilisation between 1995 and 1996 (fRiggs = 1.3, fRigge = 0.84). For pyrene, the direction and magnitude of the gas exchange is variable for both lakes. The air- water gas exchange of the heavier PAHs is considerably smaller than for phenanthrene and pyrene. 3.3.4: Metals Deposition of metals is limited to wet and dry deposition. Five years of flux estimates are available only on Lakes Huron and Ontario and more limited information is available for the early years on the other lakes. The trend in time for wet deposition is decidedly downward with 1996 fluxes on Lake Ontario being 8 times lower for lead than 1992 values. IADN Results to 1996 Page 12 ------- No consistent trend is evident from year to year for the dry deposition of metals. Deposit!onal fluxes are higher on Lake Ontario than Lake Huron for Pb and Se and they are similar for As and Cd. 3.4: Applicability oflADN Method to Estimating Urban Impacts: Case of Chicago Over recent years, several studies in the Great Lakes have shown that elevated concentrations of airborne toxic contaminants in urban areas are associated with higher-than-background deposition over adjacent waters. (Caffrey et al., 1996; Offenberg and Baker, 1997; Paode et al., 1998; Franz et al., 1998; Zhang et al, 1999; Offenberg and Baker, 1999) The IADN Master Stations were originally sited to capture only the regional background signal and therefore ignore large sources posited to have relatively limited geographic influence. Since the characterization of such sources was deemed necessary to the original long-term design of the network, (Voldner and Eisenreich, 1987) this report assesses whether the IADN approach can be used to estimate the significance of these concentrated inputs to the lakes. A full assessment of urban impacts to the Great Lakes would have to consider densely populated regions such as those at Chicago, Detroit/Windsor, Cleveland, Buffalo/Niagara Falls, Hamilton and Toronto. IADN has only one satellite station in an urban area (HT-Chicago) so loadings estimates have been prepared for 1996 data collected at LIT and at Sleeping Bear Dunes (SBD), LADN's Master Station on Lake Michigan. This comparison is not intended as an evaluation of the total urban impact to Lake Michigan but rather as a first step in using LADN's existing infrastructure to gain information about urban impacts on atmospheric deposition. To begin, the relative magnitudes of the estimated fluxes at the two sites are compared as if they occurred, undiminished, just over adjacent waters. Then, those results are extrapolated to loadings over the lake by accounting for factors such as area of influence of the urban plume. Water concentration data were unavailable for Lake Michigan for dieldrin, p,p'-DDT and metabolites, and the PAHs. In order to determine volatilisation fluxes, data from other lakes were used as estimates. p,p '-DDT water concentrations were taken from Lake Superior as it was the only lake with available data. For dieldrin and the PAHs, the higher Lake Erie data were used in order to develop conservative estimates of net downward deposition by maximising the estimated volatilisation flux. The average lakewide water surface temperature was used for both SBD and Chicago. Results are presented in Table 2. As one would expect from the elevated concentrations measured in Chicago, depositional mass fluxes from Chicago air are elevated relative to the background site. This is true for every compound and every deposition process except cis- IADN Results to 1996 Page 13 ------- Table 2: Mass Fluxes (ng/m2/d) of Atmospheric Deposition at Sleeping Bear Dunes Master Station (SBD) and Chicago. Species a-HCH dieldrin cis-chlordane trans-chlordane trans-nonachlor ODD DDE DDT g-HCH a-endosulphan b-endosulphan endosulphan sulphate HCB PCB18 PCB44 PCB52 PCB101 Sum-PCB PHEN PYR B(b+k)F B(a)P I(l,2,3-cd)P Sum-PAH (UN ECE) Wet Deposition SBD 0.71 1.4 0.18 0.45 0.045 0.084 0.19 0.43 0.31 0.65 0.37 0.33 0.043 0.08 0.046 0.1 0.064 2.3 10 6.8 12 4 6.3 23 Chicago 3.2 4.2 0.11 1.5 0.46 0.38 1.3 3.9 2.9 1.4 1.3 24 0.11 0.24 0.27 0.38 0.44 13 330 400 390 210 230 840 Dry Deposition SBD - - - - - - - - - - - - - - - - - - 5 5.1 9.2 1.9 4.8 16 Chicago - - - - - - - - - - - - - - - - - - 180 340 340 130 180 650 Gas Exchange Gas Absorption SBD 19 1.9 0.52 0.36 0.11 0.34 0.62 0.61 5.9 17 1.7 - 2.2 0.18 0.21 0.31 0.16 4.4 140 12 4.1 1.5 0.96 6.7 Chicago 38 24 6.6 5.9 1.5 0.93 5.5 8 15 22 1.9 - 5.9 4.2 8.7 8.6 5.4 130 18000 2200 71 19 23 110 Volatilisation SBD -4.9 -12 -0.68 -0.51 -0.82 -0.12 -0.75 -0.35 -0.78 -0.033 -0.00095 - -1.9 -1.3 -1.3 -0.21 -0.59 -20 -480 -57 -1.6 -1.7 -0.00037 -3.2 Chicago -6 -17 -1 -0.78 -1.4 -0.15 -1.1 -0.44 -0.95 -0.039 -0.0011 - -3.2 -2.2 -2.1 -0.33 -0.94 -33 -670 -73 -1.9 -2 -0.00044 -3.9 Net Gas Exchange SBD 14 -10 -0.15 -0.14 -0.7 0.22 -0.13 0.26 5.1 17 1.7 - 0.39 -1.1 -1 0.1 -0.43 -15 -340 -45 2.6 -0.12 0.96 3.4 Chicago 32 6.5 5.6 5.1 0.1 0.78 4.4 7.6 14 22 1.9 - 2.6 2 6.7 8.3 4.4 97 17000 2100 70 17 23 110 Total Mass Flux SBD 15 -8.6 0.03 0.31 -0.66 0.3 0.06 0.69 5.4 18 2.1 - 0.43 -1 -0.95 0.2 -0.37 -13 -330 -33 24 5.8 12 42 Chicago 35 11 5.7 6.6 0.56 1.2 5.7 12 17 23 3.2 - 2.7 2.2 7 8.7 4.8 110 18000 2800 800 360 430 1600 * Mass fluxes have been calculated directly from measurements at the overland sites at SBD and Chicago. Volatilisation estimates are based on average water concentrations in Lake Michigan; they differ due to the use of meteorological data specific to each site. IADN Results to 1996 Page 14 ------- chlordane in wet deposition though Chicago values for that compound and process demonstrated atypically large variability. All substances that show net volatilisation at the regional background site show net absorption near Chicago. The reversal in gas exchange is driven by the elevated gas-phase concentrations in Chicago air which overcome the increased volatilisation there due to higher wind speeds relative to SBD. Although it seems logical that polluted atmospheres on the shores of the lakes will induce enhanced deposit!onal fluxes to waters adjacent to overland sources, a further step must be taken to determine if those enhanced fluxes are significant on a lake-wide basis. Evaluating the latter issue requires that the mass fluxes measured at the overland sites be extended to the entire lake surface beyond the immediate proximity of the shoreline. In their work on gaseous PCB fluxes from Chicago to Lake Michigan, Zhang et al. (1999) estimated that the "urban plume" affects as much as the entire southern quarter of the lake while other studies have used more conservative estimates of 5% or less. (Offenberg and Baker, 1997; Franz et al., 1998) Measurements have shown that air and precipitation concentrations are lower over the lake than they are in Chicago, even when airflow originates in the urban area. (Offenberg and Baker, 1997; Simcik et al., 1997; Paode et al., 1998; Franz et al., 1998) For the IADN estimates, it was desired to keep the calculation simple by assigning a sub-area within the lake over which the elevated concentrations measured in Chicago could be assumed to hold and beyond which they immediately dropped to background levels as measured at SBD. Naturally, this sub-area would be smaller than the estimated plume effect area to compensate for the higher input concentration being used in the mass loading calculation. A rectangular sub- area bounded by 100km of shoreline and 10 km of adjacent water for wet and dry deposition and 20 km for gas exchange was selected. This corresponds to wet and dry particle deposition areas of 1,000 km2 (1.7% of total lake area) and a gas exchange area of 2,000 km2 (3.5% of total lake area). Not only does the lake area need to be divided to assess the effect of Chicago, but a temporal modification needs to be made as well. The IADN loading calculation normally uses the Master Station data as representative of typical conditions over the entire lake regardless of the direction of airflow. This approach does not translate directly to examining a particular source. Instead, a "time of influence" has to be devised so that only those times when the airflow is moving from the city to the water are considered for the urban influence. By examining the hourly meteorological observations made at the Chicago site, it was determined that winds were from the southwest only 32% of the time in 1996. The use of Chicago wind speeds as estimates over the adjacent water is justified by the fact that wind speeds measured from a tower anchored on a drinking water intake crib 15-km off shore from Chicago were comparable to those measured at the permanent air monitoring site on land. (Zhang et al, 1999) IADN Results to 1996 Page 15 ------- Adjusting the fluxes found in Table 2 in accordance with the conditions stated above results in the annual mass loadings presented in Table 3. The percent increases in lakewide loading due to inclusion of the urban input (termed the urban effect) are also included in the table, and negative values indicate that net background lakewide volatilisation is reduced by including high inputs from Chicago. Since lADN's mandate is to determine loadings on a lakewide basis, the network can justifiably ignore an urban influence if it is small compared to the lakewide background estimates normally calculated from Master Station data. Results in Table 3 show that wet deposition of pesticides and banned commercial chemicals over the small lake area near Chicago is not having a large lakewide effect. The one exception to this observation is for endosulphan sulphate whose elevated precipitation concentration at Chicago serves to increase the total lakewide loading by 50%. Dry particle deposition for these substances cannot be assessed because airborne particle concentrations were not measured in 1996. For gas exchange, the urban effect is more pronounced than for wet deposition, with Chicago contributing substantially to lakewide loadings for cis- and ^ram--chlordane,/\p'-DDE andp,p '-DDT, and PCB 52. Combining the influence of all deposition processes leads to large overall lakewide urban effects for cis- chlordane, DDE and PCB 52 originating in Chicago air. The urban plume loadings for PAHs are so much larger than background values that current emissions from Chicago are substantial for all modes of deposition, even with the reduced lake area and time of influence of the city used in the estimates. For wet and dry particle deposition, lakewide loadings are increased by 20% to 40% when accounting for urban inputs. For gas exchange, results are even more dramatic, with net volatilisation of the more volatile PAHs, phenanthrene and pyrene, being reduced by more than 50%. The overall effect of Chicago- generated PAHs is to increase total mass loadings of the less volatile PAHs by 20% to 40%, to cut phenanthrene's net volatilisation in half, and to bring the entire lake close to air-water equilibrium for pyrene. The preceding discussion relies on the assumption that these IADN estimates obtained by measuring urban concentrations and extending them to a small over-lake area are reasonable. Recent studies on Lake Michigan have examined the effect of the Chicago area's urban plume on depositional loadings. (Offenberg and Baker, 1997; Franz et al., 1998; Zhang et al., 1999) The drawback of these studies has typically been the small number of measurements taken over short time periods relative to lADN's regular, long-term measurements. These other studies have also incorporated rough assumptions about the area influenced by the urban plume and they have operated with spatial coverage that is only marginally better than the two sites used by IADN. IADN Results to 1996 Page 16 ------- Table 3: Lakewide Loadings to Lake Michigan: Effect of Adding Loadings from Chicago to Master Station Estimates of Regional Background (BG) Loadings. Species a-HCH dieldrin cis-chlordane trans-chlordane trans-nonachlor p,p'-DDD p,p'-DDE p,p'-DDT g-HCH a-endosulphan b-endosulphan endosulphan sulphate HCB PCB18 PCB44 PCB52 PCB101 Sum-PCB PHEN PYR B(b+k)F B(a)P I(l,2,3-cd)P Sum-PAH (UN ECE) Wet Deposition BG (kg/yr) 15 30 3.9 9.6 0.95 1.8 3.9 9 6.6 14 7.7 7 0.91 1.7 0.97 2.2 1.4 48 220 140 258 84 130 480 Chicago (kg/yr) 0.41 0.52 0.012 0.16 0.064 0.05 0.16 0.53 0.34 0.16 0.15 3.7 0.014 0.029 0.033 0.047 0.056 1.6 46 57 53 29 32 110 Urban Effect 2.7% 1.7% 0.3% 1.7% 6.7% 2.8% 4.1% 5.9% 5.2% 1.1% 1.9% 52.9% 1.5% 1.7% 3.4% 2.1% 4.0% 3.3% 20.9% 40.7% 20.5% 34.5% 24.6% 22.9% Dry Deposition BG (kg/yr) - - - - - - - - - - - - - - - - - - 100 110 197 41 100 340 Chicago (kg/yr) - - - - - - - - - - - - - - - - - - 23 43 42 15 22 79 Urban Effect - - - - - - - - - - - - - - - - - - 23.0% 39.1% 21.3% 36.6% 22.0% 23.2% Net Gas Exchange BG (kg/yr) 300 -220 -3.3 -3 -15 4.7 -2.7 5.6 110 360 36 - 8.3 -24 -22 2.2 -9.1 -320 -7200 -950 55 -2.4 20 72 Chicago (kg/yr) 8 1.6 1.3 1.2 0.023 0.2 1 1.8 3.2 5 0.41 - 0.66 0.45 1.4 1.9 0.98 22 3800 500 18 4.6 6.3 29 Urban Effect 2.7% -0.7% -39.4% -40.0% -0.2% 4.3% -37.0% 32.1% 2.9% 1.4% 1.1% - 8.0% -1.9% -6.4% 86.4% -10.8% -6.9% -52.8% -52.6% 32.7% -191.7% 31.5% 40.3% Total Mass Loading BG (kg/yr) 320 -190 0.6 6.6 -14 6.5 1.2 15 120 370 44 - 9.2 -22 -21 4.4 -7.7 -270 -6900 -700 510 120 250 890 Chicago (kg/yr) 8.4 2.1 1.3 1.4 0.087 0.25 1.2 2.3 3.5 5.2 0.56 - 0.67 0.48 1.4 1.9 1 24 3900 600 110 49 60 220 Urban Effect 2.6% -1.1% 216.7% 21.2% -0.6% 3.8% 100.0% 15.3% 2.9% 1.4% 1.3% - 7.3% -2.2% -6.7% 43.2% -13.0% -8.9% -56.5% -85.7% 21.6% 40.8% 24.0% 24.7% IADN Results to 1996 Page 17 ------- Results from these studies are compared in Table 4, where it can be seen that IADN estimates of urban-source deposition are lower than those reported elsewhere. For dry deposition of PAHs, IADN loadings are 30%-70% those estimated by Franz et al. (1998), who used smaller fluxes measured over water and a relatively larger lake area assumed to be influenced by the plume. lADN's gas exchange estimates for PCBs are only 16% of those estimated by Zhang et al. (1999), who assumed that a large portion of the lake (25%) was affected by the urban plume. For wet deposition of PCBs, it appears that the events sampled during the short study reported (Offenberg and Baker, 1997) were not representative of average values. That study reported a volume-weighted mean concentration of PCBs in Chicago rainwater of 29.3 ng/L compared to the annual IADN average of 3.46 ng/L for 1996, the only Chicago data year available in IADN. Using the summer storm data reported by Offenberg and Baker (1997) may lead to overestimates of the annual average lakewide effect of wet deposition of PCBs originating in Chicago. Table 4: Comparison of Additional Loading to Lake Michigan (kg/yr) due to Air from Chicago as Calculated by IADN and Other Studies Substance PAHs PCBs PCBs Deposition Type Dry particle Gas exchange Wet Urban Loading Estimate (kg/yr) IADN Phenanthrene 23 Pyrene 43 UNECE4 79 22 1.6 Comparison Study Phenanthrene 75 Pyrene 62 UNECE4 114 140 50 Comparison Source and Comments Franz etal., 1998 lake area used is 2.6% vs. 1 .7% in IADN individual PAH loadings estimated by pro-rating published ZPAH fluxes by mass weights presented later in same publication Zhang etal., 1999 limited AEOLOS sampling extended to a full year model set estimated fluxes (35 ug/mVyr IADN at Chicago, 9 ug/m2/yr for AEOLOS over-water) are consistent with observed AEOLOS decrease of 69% in concentration from Chicago to over-water sites lake area used is 25% vs. 3.5% for IADN Offenberg and Baker, 1997 AEOLOS results for small number of precipitation events; IADN long- term concentrations much lower lake area used is 5% vs. 1 .7% for IADN IADN Results to 1996 Page 18 ------- In light of these results and the uncertainty behind loading calculations extrapolated from limited measurements of concentration or mass flux, it appears that the IADN estimates produce results about the urban impact that are low when compared to other reported studies. Nonetheless, the results are reasonable given that they are comparable in terms of order of magnitude and reflect the differences that might be expected for lADN's consideration of Chicago versus the other studies focus on the entire urban area on the southern shores of Lake Michigan. IADN values should be viewed as lower-bound estimates at this time, providing a conservative assessment of the effect of one urban centre's air pollution on the adjacent lake's loadings of toxic substances. Even with the conservative nature of the loadings produced by this exercise, lADN's results show that an urban centre can have a significant impact on atmospheric deposition to an adjacent lake. This is true for certain banned pesticides and PCBs as well as all tested PAHs. The scenario reported here estimated the effect of only one urban centre and, in reality, that effect would likely be increased on lakes with many cities along their shores. Given current resources, further work is needed to determine an effective way for IADN to account for urban sources in its loading estimates without greatly increasing the number of routine measurements made in the network. 4. Conclusions In examining the loadings of toxic substances to the Great Lakes, three fundamental issues are considered: the magnitude of the loadings, the manner in which each loading component contributes to the total, and the variation or trends in the loadings across the basin and over many years. For 1995-96, typical fluxes of banned organochlorine pesticides are on the order of 0.1 to 1 ng/m2/d and only regularly exceed 10 ng/m2/d for the gas exchange of a-HCH and dieldrin. Fluxes of individual PCB congeners are typically between 0.1 and 1 ng/m2/d for each loading component, similar to many of the banned organochlorine pesticides, although seasonal volatilisation fluxes of £PCB are sometimes higher than 50 ng/m2/d. HCB gas exchange fluxes are in the 1 to 10 ng/m2/d range and fluxes of current-use pesticides y-HCH and the endosulphans are on the order of 1 to 5 ng/m2/d. Inputs to the lakes of pesticides and PCBs are dominated by gas exchange and wet deposition. Dry particle concentration measurements ceased after 1995 due to low reported levels, but loading estimates presented here showed that dry particle deposition of dieldrin, p,p '-ODD and PCBs may be significant when compared to the other deposition processes. Dieldrin and £PCB volatilisation rates are greater than gas absorption so the lakes are acting as sources of these substances to the atmosphere. IADN Results to 1996 Page 19 ------- Inputs of PAHs and metals are larger than those of pesticides and PCBs as expected by their continued emission to the environment. PAH fluxes range from 1 to 1000 ng/m2/d depending on species and loading process, and fluxes of trace metals reach values as high as 2000 ng/m2/d. Since metals are non-volatile, they are subject only to wet and dry deposition with the wet fluxes typically being the larger of the two. Available data indicate that PAH volatilisation from the lakes is small compared to the other flux terms, and gas absorption is substantial for phenanthrene and pyrene while the higher molecular weight PAHs are delivered mostly by wet and dry particle deposition. As part of its quality assurance program, IADN has begun a new set of intercomparison studies between its participating agencies. Until results are available, comparisons of depositional behaviour between lakes and over time have been limited to those situations where data were generated by the same operating agency. Wet deposition fluxes are generally decreasing in time for the banned OC pesticides while dry deposition and gas exchange fluxes have been variable. The temporal trend in gas exchange is generally toward air-water equilibrium. For PCBs, wet deposition is steady in time while dry deposition was increasing before measurements ceased in 1995. Gas exchange of PCBs is in the direction of volatilisation on all lakes but generally approaching air-water equilibrium. Wet and dry particle deposition of PAHs show no consistent trends in time. Levels increase from west to east across the basin. Little net gas exchange flux information is presented for PAHs since water concentration data are sparse. Deposition of metals is limited to wet and dry deposition with wet deposition declining in time and dry deposition being variable. Loading estimates produced by IADN have traditionally been based on the assumption that Master Stations located at remote sites on the lakes are characterizing the regional background deposition. However, strong inputs with more limited geographic influence are also likely to exist near cities and industrial areas. Using the case of Chicago on Lake Michigan as an example, data from 1996 were used to assess the impact of air pollution from an urban centre on deposition to the lakes. The IADN calculation was modified to include a small lake sub-area influenced by the high concentrations measured at Chicago and, though results should be viewed as lower-bound estimates when compared to other studies, deposition from Chicago sources is still estimated to be substantial for certain pesticides and PCBs and for all PAHs. Further work is needed to correctly characterize the lake area affected by urban air pollution and deduce effective ways of incorporating significant urban centres in IADN loading estimates. IADN Results to 1996 Page 20 ------- Acknowledgements Special thanks go to the many people whose work supports the production of IADN loadings results. Site operators on Lake Superior - Don Keith and Pat Keith (Eagle Harbor), Ron Perala (Brule River), Kurt Nead (Wolf Ridge), Carl Neilson (Sibley) and Larry Barnett (Turkey Lakes) Site operators on Lake Michigan - Tom van Zoeren and Alice Van Zoeren (Sleeping Bear Dunes), Shelley Thomas (UT-Chicago) Site operators on Lake Huron - Mark Witty, Nancy Witty, Bonnie Bailey, Floyd Orford and Colleen Blackburn (Burnt Island), Terry Romphf (Grand Bend for Ecosystem Health Division of Environment Canada's Ontario Region), Scott Kennedy and Mike Parker (Grand Bend for the Ontario Ministry of the Environment) Site operators on Lake Erie - Lynn Romano (Sturgeon Point), Gary Mouland (Pelee Island), Scott Kennedy (Port Stanley), Tony Bucsis (Rock Point) Site operator on Lake Ontario - Darrel Smith (Point Petre) Nick Alexandrou, Ky Su, Richard Park and Kulbir Banwait at the Organics Analysis Laboratory of Environment Canada's Meteorological Service of Canada Helena Dryfhout-Clark, Chris Green, Brian Martin, Frank MacLean and Jim Woods at the Centre for Atmospheric Research Experiments of Environment Canada's Meteorological Service of Canada Bruce Harrison and MaryLou Archer at the Ecosystem Health Division of Environment Canada's Ontario Region the Organic Analysis Laboratory at Environment Canada's National Laboratory for Environmental Testing Matt O'Dell and Karen Arnold at Indiana University, and Sylvia Cussion, Paul Yang, Dan Toner, Mike Sage, Louis Au and Renee Luniewski at the Ontario Ministry of the Environment Bill Sukloff of Environment Canada's Meteorological Service of Canada for RDMQ support Laura Hanson-Smith of AQTS and Greg Skelton of G.B. Skelton Technical Services for data entry and quality control Marvin Palmer at the US EPA's Great Lakes National Program Office and Serge L'ltalien at Environment Canada's Ontario Region Ecosystem Health Division for generous provision of lake water concentration data used in this report IADN Results to 1996 Page 21 ------- IADN Results to 1996 Page 22 ------- References Bamford, H.A., D.L. Poster and I.E. Baker. (1999) Temperature dependence of the HLC of thirteen PAHs between 4°C and 3l°C. Environ. Toxicol. Chem. 18(9): 1905-1912. Brunner, S., E. Hornung, H. Santl, E. Wolff, O.G. Piringer, J. Altschuh and R. Bruggemann. (1990) Henry's law constants for poly chlorinated biphenyls: experimental determination and structure-property relationships. Environ. Sci. Technol. 24(11): 1751-1754. Caffrey, P.P., A.E. Suarez, J.M. Ondov and M. Han. (1996) Importance of fine particle loading to fluxes of trace elements dry deposition onto Lake Michigan. J. Aerosol Sci. 27(Suppl. 1): S32-S32. Cortes, D.R., I. Basu, C.W. Sweet, K.A. Brice, R.M. Hoff and RA. Kites. (1998) Temporal trends in gas-phase concentrations of chlorinated pesticides measured at the shores of the Great Lakes. Environ. Sci. Technol. 32(13): 1920-1927. Cortes, D.R., R.M. Hoff, K.A. Brice and R.A. Kites. (1999) Evidence of current pesticide use from temporal and Clausius-Clapeyron plots: a case study from the Integrated Atmospheric Deposition Network. Environ. Sci. Technol. 33(13):2145-2150. Cortes, D.R., I. Basu, C.W. Sweet and R.A. Kites. (2000) Temporal trends in and influence of wind on PAH concentrations measured near the Great Lakes. Environ. Sci. Technol. 34(3):356-360. Gotham, W.E., Jr. and T.F. Bidleman. (1991) Estimating the atmospheric deposition of organochlorine contaminants to the Arctic. Chemosphere 22(1-2): 165-188. Eisenreich, S.J. and W.MJ. Strachan. (1992) Estimating atmospheric deposition of toxic substances to the Great Lakes: an update. Report of the Workshop at Burlington, ON, Canada, January 31-February 2, 1992. Franz, T.P., S.J. Eisenreich and T.M. Holsen. (1998) Dry deposition of particulate polychlorinated biphenyls and polycyclic aromatic hydrocarbons to Lake Michigan. Environ. Sci. Technol. 32(23):3681-3688. Hillery, B.R., I. Basu, C.W. Sweet and R.A. Kites. (1997) Temporal and spatial trends in a long-term study of gas-phase PCB concentrations near the Great Lakes. Environ. Sci. Technol. 31(6):1811-1816. IADN Results to 1996 Page 23 ------- Hfflery, B.R., M.F. Simcik, I. Basu, R.M. Hoff, W.MJ. Strachan, D. Burniston, C.H. Chan, K.A. Brice, C.W. Sweet, and R.A. Kites. (1998) Atmospheric deposition of toxic pollutants to the Great Lakes as measured by the Integrated Atmospheric Deposition Network. Environ. Sci. Technol. 32(15):2216-2221. Hoff, R.M. (1994) An error budget for the determination of the atmospheric mass loading of toxic chemicals in the Great Lakes. J. Great Lakes Res. 20(l):229-239. Hoff, R.M., W.MJ. Strachan, C.W. Sweet, C.H. Chan, M. Shackleton, T.F. Bidleman, K.A. Brice, D.A. Burniston, S. Cussion, D.F. Gatz, K. Harlin, and W.H Schroeder. (1996) Atmospheric deposition of toxic chemicals to the Great Lakes: a review of data through 1994. Atmos. Env. 30(20):3505-3527. Hoff, R.M., K.A. Brice and C. J. Halsall. (1998) Nonlinearity in the slopes of Clausius- Clapeyron plots for SVOCs. Environ. Sci. Technol. 32(12): 1793-1798. Holsen, T.M., K.E. Noll, S. Liu and W. Lee. (1991) Dry deposition of polychlorinated biphenyls in urban areas. Environ. Sci. Technol. 25(6): 1075-1081. Hornbuckle, K.C., J.D. Jeremiason, C.W. Sweet and SJ. Eisenreich. (1994) Seasonal variations in air-water exchange of polychlorinated biphenyls in Lake Superior. Environ. Sci. Technol. 28(8):1491-1501. Iwata, H, S. Tanabe, K.Ueda and R. Tatsukawa. (1995) Persistent organochlorine residues in air, water, sediments and soils in the Lake Baikal region, Russia. Environ. Sci. Technol. 29(3):792-801. Jantunen, L.M.M. and T.F. Bidleman. (2000) Temperature dependent Henry's law constant for technical toxaphene. Chemosphere-Global Change Science 2:225-231. Junge, C.E. (1977) Basic considerations about trace constituents in the atmosphere as related to the fate of global pollutants. In Fate of Pollutants in the Air and Water Environments, I.H. Suffet, ed. Part I, pp 7-26. John Wiley, New York. Mackay, D. (1991) Multimedia Environmental Models: The Fugacity Approach. Lewis Publishers, Chelsea, Michigan. Mackay, D., W.Y. Shiu and K.C. Ma. (1992) Illustrated Handbook of Physical-chemical Properties and Environmental Fate for Organic Chemicals. Volume I: Monoaromatic Hydrocarbons, Chlorobenzenes, and PCBs. Lewis Publishers, Boca Raton, Florida. IADN Results to 1996 Page 24 ------- Murphy, T.J., M.D. Mullin and J.A. Meyer. (1987) Equilibration of polychlorinated biphenyls and toxaphene with air and water. Environ. Sci. Technol. 21(2): 155-162 NOAA. (1999) Great Lakes Environmental Research Laboratory Data Library. http://www.glerl.noaa.gov/data/data.html Offenberg, J.H. and I.E. Baker. (1997) Polychlorinated biphenyls in Chicago precipitation: enhanced wet deposition to near-shore Lake Michigan. Environ. Sci. Technol. 31(5): 1534- 1538. Offenberg, J.H. and I.E. Baker. (1999) Aerosol size distributions of polycyclic aromatic hydrocarbons in urban and over-water atmospheres. Environ. Sci. Technol. 33(19):3324- 3331. Paode, R.D., S.C. Sofuoglu, J. Sivadechathep, K.E. Noll, T.M. Holsen and GJ. Keeler. (1998) Dry deposition fluxes and mass size distributions of Pb, Cu, and Zn measured in southern Lake Michigan during AEOLOS. Environ. Sci. Technol. 32(11): 1629-1635. Pankow, J.F. (1987) Review and comparative analysis of the theories on partitioning between the gas and aerosol particulate phases in the atmosphere. Atmos. Env. 21(11):2275-2283. Reid, R.C., J.M. Prausnitz and B.E. Poling. (1987) The Properties of Gases and Liquids. McGraw-Hill, Toronto. Rice, C.P., S.M. Chernyak, C. J. Hapeman and S. Bilboulian. (1997) Air-water distribution of the endosulfan isomers. J. Environ. Qual. 26(4): 1101-1106. Schwarzenbach, R.P., P.M. Gschwend and D. M. Lnboden. (1993) Environmental Organic Chemistry. Wiley Interscience, New York. Simcik, M.F., H. Zhang, SJ. Eisenreich and T.P. Franz. (1997) Urban contamination of the Chicago/coastal Lake Michigan atmosphere by PCBs and PAHs during AEOLOS. Environ. Sci. Technol. 31(7):2141-2147. Simcik, M.F., I. Basu, C.W. Sweet and R.A. Kites. (1999) Temperature dependence and temporal trends of polychlorinated biphenyl congeners in the Great Lakes atmosphere. Environ. Sci. Technol. 33(12): 1991-1995. Simcik, M.F., R.M. Hoff, W.MJ. Strachan, C.W. Sweet, I. Basu and RA. Kites. (2000) Temporal trends of semivolatile organic contaminants in Great Lakes precipitation. Environ. Sci. Technol. 34(3):361-367. IADN Results to 1996 Page 25 ------- Strachan, W.M.J. and S J. Eisenreich. (1988) Mass balancing of toxic chemicals in the Great Lakes: the role of atmospheric deposition. Appendix I from the Workshop on the Estimation of Atmospheric Loadings of Toxic Chemicals to the Great Lakes Basin, Scarborough, ON, Canada, October 29-31, 1986. Sukloff, W.B., S. Allan and K. Ward. (1995) RDMQ User Manual. Environment Canada, Toronto, ON. Suntio, L.R., W.Y. Shiu, D. Mackay, J.N. Sieber and D. Glotfelty. (1987) A critical review of Henry's law constants. Rev. Envir. Contain. Toxicol. 103:1-59. Tateya, S., S. Tanabe and R. Tatsukawa. (1988) PCBs on the globe: possible trend of future levels in the open ocean. In Toxic Contamination in Large Lakes, Volume HI: Sources, Fate and Controls of Toxic Contaminants. N.W. Schmidtke, ed. Lewis Publishers, Chelsea, Michigan. Taylor, J.K. (1990) Statistical techniques for data analysis. Lewis Publishers, Boca Raton, Florida. Ten Hulscher, T.E.M., L.E. Van Der Velde and W. A. Bruggeman. (1992) Temperature dependence of FtLCs for selected chlorobenzenes, PCBs and PAHs. Environ. Toxicol. Chem. 11(11):1595-1603. United Nations Economic Commission for Europe. (1998) 1998 Aarhus Protocol on Persistent Organic Pollutants (POPs). Protocol to the 1979 Convention on Long-range Transboundary Air Pollution. http://www.unece.org/env/lrtap/protocol/98pop_a/annex3 .htm Voldner, E.G. and SJ. Eisenreich. (1987) A plan for assessing atmospheric deposition to the Great Lakes: scientific background. Report of the Atmospheric Deposition Monitoring Task Force to The Surveillance Work Group, Water Quality Board, International Joint Commission. Zhang, H., SJ. Eisenreich, T.R. Franz, I.E. Baker and J.H. Offenberg. (1999) Evidence for increased gaseous PCB fluxes to Lake Michigan from Chicago. Environ. Sci. Technol. 33(13):2129-2137. IADN Results to 1996 Page 26 ------- Appendix A: Derivation of Simplified Mass Transfer Coefficients IADN Results to 1996 Page 27 ------- IADN Results to 1996 Page 28 ------- Starting with the formulations presented in Hornbuckle et al. (1994), the water-side mass transfer coefficient for CO2 can be expressed as (1) where kW:Co2 = water-side mass transfer coefficient of CC>2 (cm/h) UIQ = wind speed measured at 10 m above ground level (m/s). kw, co2 is related to the mass transfer coefficient for another substance, x, by rt \ -0.5 / 0 N -0.5 fy\ Sex } .,.( Sc* } (2) - - = 0.4W'64 - - iccoi/ \SccoiJ where kw>x = water-side mass transfer coefficient of substance x (cm/h) Sc = Schmidt number (-). Schmidt number is the dimensionless ratio of kinematic viscosity to diffusivity. With windspeeds measured directly, one need only determine the ratio of Schmidt numbers for CO2 and the substance of concern to arrive at an estimate of the water-side mass transfer coefficient as in Equation (2). Previous work has sought to determine Schmidt numbers directly (e.g. Hornbuckle et al. , 1994) , but an examination of the desired ratio shows that this is an unnecessary operation since the viscosity term relates only to the solvent and is unaffected by the solute under consideration. As a result, viscosities in numerator and denominator of Equation (3) cancel out and make the ratio of Schmidt numbers equivalent to the ratio of diffusivities. Sc* (n/D)* (Deo 2} (3) Scco2 (nl D)co2 V D: where n = kinematic viscosity, [L2/T], e.g. (cm2/s) D = diffusivity, [L2/T], e.g. (cm2/s) The Wilke-Chang method (see Reid et al., 1987) can be used to determine diffusivities as ~~ nV °-6 fM' m where D = diffusion coefficient of solute x in solvent S (cm2/s) O = association factor of solvent S (-) Ms = molecular weight of solvent S (g/mol) IADN Results to 1996 Page 29 ------- T = temperature (K) ]i = dynamic viscosity of solvent S (cP) Vm = molar volume of solute at its normal boiling temperature (cmVmol). Since the solvent properties and temperature are the same for the solvent S whether diffusion of substance x or the reference substance CC>2 is being considered, several terms cancel out when calculating the ratio of diffusivities needed to solve Equation (3). That ratio reduces to the ratio of molar volumes of the solutes raised to the power 0.6. With the molar volume of CC>2 being 29.6 cffiVmol (Reid et a/., 1987), Sc* Dco^ fF»,*Y'6 (5) Scco2 D* \29.6; and then substituting back into (2) leads to the water-side mass transfer coefficient (cm/h) ,, = 0.45mo - = 0.45mo 0.6 , , . . \Scco \\.29.6J \29.6 Similar simplifications can be made for ka, the air-side mass transfer coefficient. .3 (7) where ka = air-side mass transfer coefficient of water (cm/s) and ( Da,, V-61 (8) where DajX = diffiisivity of compound x in air, [L2/T], e.g. (cm2/s) Da,H2o = diffiisivity of water in air, [L2/T], e.g. (cm2/s) The diffusivities here are typically calculated by the Fuller et al. method (see Reid et a/., 1987) for diffusion of solute x in solvent S as 0.001437'75 (9) where P = pressure (bar) MxS = inverse weighted average mass of solute x and solvent S = 2(Mx-1+Ms-1)-1(g/mol) IADN Results to 1996 Page 3 0 ------- d) = sum of atomic diffusion volumes for compound constituents When taking the ratio necessary to the air-side mass transfer coefficient calculation, many of the terms cancel out so that Da,x \LVd)air I (10) and, substituting values from Reid et al. (1987), air = 19.7 and fcVjmo =13.1 M air = 29 g/mol andMff2o =18 g/mol, leads to Da,* l/29)°5(l3.11/3+19.71/3)2 _ (l/M + 1/29) 85.3 0.5 l/29)05((ZFdy/3+19.71/3)2 19.7173)' (11) which requires knowledge only of the molecular mass and sum of molecular diffusion volumes for the compound of interest in order to estimate its diffusivity in air relative to that of water. The air-side mass transfer coefficient, expressed in cm/s, then reduces to ka,x = ka. H2O Da,x Da,Hit 0.61 = 15(0.2wio 1/29)C ((ZF,V/3+19.71/3)2 0.61 (12) IADN Results to 1996 Page 31 ------- IADN Results to 1996 Page 3 2 ------- Appendix B: Selected Data Used in Calculating IADN Loadings IADN Results to 1996 Page 3 3 ------- IADN Results to 1996 Page 3 4 ------- Table Bl: Summary of Meteorological Data at IADN Master Stations, 1992-1996 Lake 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 281.8 4.78 1993 990 278.4 3.09 1214 280.0 2.94 1110 280.8 3.50 1389 283.6 2.77 1021 281.8 4.98 1994 665 278.4 2.99 866 280.0 2.90 896 280.8 3.38 1073 283.6 2.63 837 281.1 4.66 1995 904 279.2 3.20 1182 282.5 3.04 931 281.8 3.69 933 284.2 2.99 816 282.9 4.71 1996 1148 277.7 2.84 1200 280.8 2.89 908 280.4 3.36 823 283.4 2.78 1000 281.7 4.51 IADN Results to 1996 Page 35 ------- Table B2: Lake Water Concentrations for IADN Loadings Estimates of 1995-96 Substance cc-HCH dieldrin CK-chlordane trans -chlordane p,p'-DDD p,p'-DDE p,p'-DDT y-HCH cc-endosulphan P-endosulphan HCB PCB18 PCB44 PCB52 PCB101 S-PCB phenanthrene pyrene B(b+k)F B(a)P I(l,2,3-cd)P ^PAH(UNECE) Lake Superior Cone. fna/LI 1.8988 0.1184 0.0070 0.0042 0.0079 0.0060 0.0100 0.3277 0.0138 0.0038 0.0071 0.0025 0.0038 0.0048 0.0027 0.0705 0.5481 0.1298 0.0863 0.0355 0.0467 0.1684 n 67 64 64 37 37 37 37 67 64 64 66 3 3 3 3 3 27 27 27 27 27 - COV (%) 17 14 43 136 21 57 176 30 104 187 172 13 33 30 42 24 52 110 40 70 100 - Source 1,2,3,4,5 1,2,3,4,5 2,3,4,5 2,3 2,3 2,3 2,3 1,2,3,4,5 1,2,3,4,5 1,2,3,4,5 1,2,3,4,5 1 1 1 1 1 4,5 4,5 4,5 4,5 4,5 4,5 Lake Michigan Cone. fna/LI 0.2342 - 0.0059 0.0037 _ _ - 0.0686 - _ 0.0074 0.0058 0.0063 0.0011 0.0034 0.0969 _ - - _ - - n 3 - 3 3 _ _ - 3 - _ 3 3 3 3 3 3 _ - - _ - - COV (%1 9 - 22 18 _ _ - 6 - _ 16 25 13 147 13 3 _ - - _ - - Source 1 . 1 1 _ . ; . _ ; ; ; ; ; ; . - Lake Huron Cone. fna/LI 0.5519 - 0.0033 0.0023 _ _ - 0.1158 - _ 0.0095 0.0039 0.0030 0.0019 0.0017 0.0500 _ - - _ - - n 3 - 3 3 _ _ - 3 - _ 3 3 3 3 3 3 _ - - _ - - COV <%) 20 - 18 19 _ _ - 22 - _ 22 15 8 12 5 9 _ - - _ - - Source 1 . 1 1 _ . ; . _ ; ; ; ; ; ; . - Lake Erie Cone. fna/LI 0.5397 0.1531 0.0046 0.0033 _ _ - 0.1747 0.1300 0.0700 0.0107 0.0120 0.0101 0.0093 0.0052 0.1662 4.6821 1.2482 0.6433 0.2660 0.4555 1.3648 n 30 26 3 3 _ _ - 30 21 8 18 3 3 3 3 3 27 25 18 21 13 - COV (%1 33 32 25 21 _ _ - 94 92 86 277 41 31 69 82 64 95 72 161 105 231 - Source 1,6 1,6 1 1 1,6 1,6 1,6 1,6 1 1 1 1 1 6 6 6 6 6 6 Lake Ontario Cone. fna/LI 0.4660 0.2416 0.0054 0.0049 _ _ - 0.1658 0.0260 0.0400 0.0140 0.0072 0.0076 0.0057 0.0032 0.0979 1.4180 0.5584 0.3031 0.1758 - - n 27 24 3 3 _ _ - 27 24 24 26 3 3 3 3 3 24 24 24 24 - - COV <%) 25 27 4 8 _ _ - 41 65 100 81 9 4 24 19 11 64 69 84 30 - - Source 1,7 1,7 1 1 1,7 1,7 1,7 1,7 1 1 1 1 1 7 j j 7 - Data Sources: 7 US R/VLake Guardian cruise of 1996 analysed by US EPA GLNPO; 2 CCGVLimnos cruise of spring 1996 analysed by EC NWRI; 3 CCGVLimnos cruise of summer 1996 analysed by EC NWRI; 4 CCGVLimnos cruise of spring 1996 analysed by EC EHD; 5 CCGVLimnos cruise of summer 1996 analysed by EC EHD; 6 CCGVLimnos cruise of 1995 analysed by EC EHD; 7 CCGV Limnos cruise of 1998 analysed by EC EHD. N.B. Multiple source measurements have been pooled with adjustment for sample sizes and precisions. (Taylor, 1990) IADN Results to 1996 Page 36 ------- Appendix C: IADN Mass Loadings for 1995 and 1996 IADN Results to 1996 Page 3 7 ------- IADN Results to 1996 Page 3 8 ------- Table Cl: Atmospheric Fluxes to Lake Superior for 1995 (a) Banned Organochlorine Pesticides Species Season a-HCH W Sp Su F Annual dieldrin W Sp Su F Annual cis- W chlordane Sp Su F Annual trans- W chlordane Sp Su F Annual trans- W nonachlor Sp Su F Annual p,p'-DDD W Sp Su F Annual p,p'-DDE W Sp Su F Annual p,p'-DDT W Sp Su F Annual Lake Superior 1995 Wet Deposition Mean ng/m2/d 1.5 0.12 0.6 1.6 0.94 0.34 0.76 0.53 2.9 1.1 0.21 0.015 0.031 0.066 0.079 0.1 0.16 0.061 0.31 0.16 0.016 0.017 0.011 0.099 0.036 0.05 0.025 0.016 0.027 0.03 0.2 0.07 0.042 0.31 0.15 0.027 0.055 0.052 0.093 0.057 cov % 120 210 100 100 140 54 18 55 54 68 160 100 54 100 270 150 120 180 170 120 32 240 100 - 390 150 130 140 150 150 130 74 59 96 150 26 230 120 71 150 Dry Deposition Mean ng/m2/d 0.54 0.015 0.0085 0.064 0.16 0.3 0.77 0.66 0.33 0.51 0.083 0.056 0.021 0.025 0.046 0.061 0.04 0.026 0.024 0.038 0.046 0.017 0.02 0.016 0.022 0.0092 0.032 0.016 0.01 0.017 0.063 0.022 0.029 0.013 0.032 0.02 0.036 0.24 0.022 0.079 COV % 100 110 100 140 200 140 100 110 100 110 100 100 120 130 120 160 100 110 110 130 150 120 110 110 130 100 140 120 100 140 100 100 100 120 120 100 140 150 100 210 Gas Exchange Gas Absorption Mean ng/m2/d 29 26 30 32 29 0.33 1.5 4.4 1.3 1.9 0.74 0.51 0.83 0.39 0.62 2.5 0.3 0.54 0.22 0.9 0.13 0.1 0.21 0.064 0.13 0.057 0.13 0.25 0.14 0.14 0.16 0.21 0.4 0.33 0.27 0.32 0.67 0.45 0.17 0.4 COV % 59 64 77 79 72 190 140 91 100 150 130 81 88 83 110 160 96 100 65 170 190 100 92 81 140 93 120 110 140 130 69 100 92 93 110 120 140 100 110 140 Volatilisation Mean ng/m2/d -30 -23 -46 -49 -37 -8.6 -6.6 -11 -13 -9.8 -0.81 -0.62 -0.89 -1.1 -0.86 -0.61 -0.47 -0.6 -0.8 -0.62 -0.41 -0.31 -0.32 -0.46 -0.38 -0.082 -0.063 -0.14 -0.15 -0.11 -0.77 -0.59 -0.82 -1.1 -0.81 -0.26 -0.2 -0.41 -0.45 -0.33 COV % 53 53 53 53 53 52 52 52 52 52 66 66 66 66 66 140 140 140 140 140 140 140 140 140 140 54 54 54 54 54 76 76 76 76 76 180 180 180 180 180 Net Gas Exchange Mean ng/m2/d -0.28 2.7 -16 -17 -7.5 -8.3 -5.1 -6.6 -12 -7.9 -0.077 -0.11 -0.054 -0.74 -0.24 1.9 -0.17 -0.063 -0.58 0.27 -0.27 -0.21 -0.12 -0.4 -0.25 -0.025 0.069 0.11 -0.0067 0.037 -0.61 -0.38 -0.42 -0.73 -0.54 0.063 0.47 0.042 -0.28 0.074 COV % 3800 410 130 140 290 52 67 75 53 70 1200 390 1300 90 390 210 410 1500 200 3300 220 210 400 160 250 200 210 230 2800 310 88 110 140 100 130 920 210 2000 290 820 IADN Results to 1996 Page 39 ------- (b) Current-use Pesticides Species Season g-HCH W (lindane) Sp Su F Annual a- W endosulphan Sp Su F Annual b- W endosulphan Sp Su F Annual endosulphan W sulphate Sp Su F Annual Lake Superior 1995 Wet Deposition Mean ng/m2/d 0.31 0.044 0.58 0.34 0.32 3.4 0.028 0.6 1 1.3 0.41 2.3 1.4 0.072 1 1.7 0.65 0.64 0.11 0.79 cov % 110 35 160 130 180 140 63 150 150 270 78 87 140 110 110 11 60 58 - 84 Dry Deposition Mean ng/m2/d 0.093 0.057 0.031 0.066 0.062 0.53 0.82 1.4 0.56 0.83 0.009 0.075 0.57 0.096 0.19 - - - - - COV % 100 110 130 130 120 150 100 110 120 120 100 150 140 170 200 - - - - - Gas Exchange Gas Absorption Mean ng/ni2/d 2 2 8.6 7.8 4 5.6 0.22 1.6 31 3.3 9.1 0.058 0.16 1.8 0.26 0.57 - - - - - COV % 64 75 75 80 97 120 130 110 120 220 100 120 96 200 190 - - - - - Volatilisation Mean ng/ni2/d -2.9 -2.3 -4.2 -4.5 -3.5 -0.0035 -0.003 -0.0035 -0.004 -0.0035 -3.3E-05 -2.5E-05 -5.9E-05 -6.1E-05 -4.5E-05 - - - - - COV % 58 58 58 58 58 120 120 120 120 120 190 190 190 190 190 - - - - - Net Gas Exchange Mean ng/ni2/d -0.7 6.3 3.6 -0.51 2.2 0.21 1.6 31 3.3 9.1 0.058 0.16 1.8 0.26 0.57 - - - - - COV % 180 92 140 560 250 120 130 110 120 220 100 120 97 200 190 - - - - - (c) Banned Organochlorine Commercial Chemicals Species Season HCB W Sp Su F Annual PCB18 W Sp Su F Annual PCB44 W Sp Su F Annual PCB52 W Sp Su F Annual PCB101 W Sp Su F Annual Sum-PCB W Sp Su F Annual Lake Superior 1995 Wet Deposition Mean ng/m2/d 0.044 0.042 0.021 0.09 0.049 0.045 0.04 0.039 0.14 0.066 0.053 0.055 0.039 0.15 0.075 0.016 0.068 0.037 0.23 0.087 0.081 0.083 0.047 0.2 0.1 2.2 1.7 1 4.4 2.3 COV % 42 56 40 41 68 12 90 47 27 140 35 110 55 45 130 110 60 130 120 320 14 160 27 19 140 54 150 36 44 140 Dry Deposition Mean ng/m2/d 0.024 0.014 0.011 0.0067 0.014 0.061 0.066 0.088 0.034 0.062 0.036 0.084 0.058 0.055 0.058 0.072 0.11 0.089 0.05 0.08 0.054 0.052 0.049 0.032 0.047 1.6 9 1.8 0.93 1.6 COV % 110 110 100 110 120 100 100 110 100 110 110 110 100 130 110 110 100 100 100 110 100 100 100 100 100 100 100 100 100 110 Gas Exchange Gas Absorption Mean ng/m2/d 3.7 3.6 1.9 1.8 2.7 0.16 0.2 0.17 0.14 0.17 0.21 0.79 0.64 0.53 0.54 0.36 0.82 0.77 0.59 0.63 0.19 0.76 0.6 0.36 0.48 6.6 16 12 8.9 11 COV % 59 63 60 70 64 76 74 73 94 85 79 100 98 100 110 90 83 96 94 110 88 97 89 94 110 88 82 88 94 97 Volatilisation Mean ng/m2/d -2.2 -1.7 -1.6 -2.3 -1.9 -0.7 -0.54 -0.52 -0.76 -0.63 -0.89 -0.69 -0.71 -1 -0.82 -1 -0.8 -0.86 -1.2 -0.97 -0.52 -0.4 -0.46 -0.64 -0.51 -24 -19 -16 -24 -21 COV % 180 180 180 180 180 52 52 52 52 52 60 60 60 60 60 58 58 58 58 58 65 65 65 65 65 55 55 55 55 55 Net Gas Exchange Mean ng/m2/d 1.5 1.9 0.28 -0.49 0.8 -0.54 -0.35 -0.35 -0.62 -0.46 -0.68 0.1 -0.066 -0.47 -0.28 -0.66 0.025 -0.09 -0.6 -0.33 -0.33 0.35 0.14 -0.28 -0.031 -18 -2.9 -3.9 -15 -9.9 COV % 260 180 1000 840 490 55 62 59 55 60 69 710 900 130 430 79 2400 760 110 350 92 190 360 150 790 65 390 250 78 67 IADN Results to 1996 Page 40 ------- (d) Currently-Emitted PAHs and Metals Species Season PHEN W Sp Su F Annual PYR W Sp Su F Annual B(b+k)F W Sp Su F Annual B(a)P W Sp Su F Annual I(l,2,3-cd)P W Sp Su F Annual sum-PAH W (UN ECE) Sp Su F Annual Pb W Sp Su F Annual As W Sp Su F Annual Se W Sp Su F Annual Cd W Sp Su F Annual Lake Superior 1995 Wet Deposition Mean ng/m2/d 6.7 3.6 3.5 53 17 5.4 2.3 1.7 51 15 9.4 5.6 2.8 67 21 2.1 1.8 0.78 18 5.6 5.3 2.4 0.97 31 9.9 17 9.7 4.6 120 37 - - - - - - - - - - - - - - - - - - - - cov % 95 43 36 65 190 100 61 35 67 230 54 45 33 - 150 86 79 54 71 170 110 14 61 - 190 48 31 28 - 100 - - - - - - - - - - - - - - - - - - - - Dry Deposition Mean ng/m2/d 3.3 1.3 1.7 1.5 2 2.4 1.2 2.2 1.4 1.8 8.1 1.7 4.6 6.8 5.3 0.38 0.56 0.81 0.47 0.55 1.4 0.73 1.6 1.3 1.3 10 3 7 8.7 7.2 - - - - - - - - - - - - - - - - - - - - COV % 100 100 100 120 110 110 130 110 140 120 110 72 81 140 120 100 100 100 100 110 150 100 110 150 130 110 100 100 140 120 - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/ni2/d 87 95 140 670 250 3.9 3.3 98 260 91 4 4.2 3.5 15 6.7 4.2 1.6 1.3 3.8 2.7 0.97 0.98 0.8 0.98 0.93 9.2 6.7 5.6 20 10 - - - - - - - - - - - - - - - - - - - - COV % 91 110 70 230 280 130 95 240 250 350 61 64 58 150 160 150 66 58 160 150 58 66 58 59 61 76 44 40 120 110 - - - - - - - - - - - - - - - - - - - - Volatilisation Mean ng/ni2/d -56 -44 -61 -75 -59 -5.4 -4.3 -6.6 -7.5 -6 -0.14 -0.11 -0.24 -0.25 -0.18 -0.15 -0.11 -0.26 -0.27 -0.2 -2.5E-05 -1.9E-05 -4.4E-05 -4.5E-05 -3.3E-05 -0.29 -0.22 -0.5 -0.52 -0.38 - - - - - - - - - - - - - - - - - - - - COV % 72 72 72 72 72 120 120 120 120 120 64 64 64 64 64 86 86 86 86 86 110 110 110 110 110 54 54 54 54 54 - - - - - - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/ni2/d 31 50 82 590 190 -1.5 -1 91 250 85 3.9 4.1 3.3 15 6.5 4.1 1.5 1 3.5 2.5 0.97 0.98 0.8 0.98 0.93 8.9 6.5 5.1 19 10 - - - - - - - - - - - - - - - - - - - - COV % 240 190 110 250 360 510 530 260 250 370 62 65 60 160 170 160 69 65 170 160 58 66 58 59 61 78 44 42 120 120 - - - - - - - - - - - - - - - - - - - - IADN Results to 1996 Page 41 ------- Table C2: Atmospheric Fluxes to Lake Superior for 1996 (a) Banned Organochlorine Pesticides Species Season a-HCH W Sp Su F Annual dieldrin W Sp Su F Annual cis- W chlordane Sp Su F Annual trans- W chlordane Sp Su F Annual trans- W nonachlor Sp Su F Annual p,p'-DDD W Sp Su F Annual p,p'-DDE W Sp Su F Annual p,p'-DDT W Sp Su F Annual Lake Superior 1996 Wet Deposition Mean ng/m2/d 3.2 2.3 2.1 1.8 2.4 0.71 0.58 0.63 0.74 0.66 0.082 0.0099 0.062 0.19 0.087 0.072 0.036 0.37 0.87 0.34 0.087 0.018 0.037 0.037 0.045 0.026 0.0059 0.011 0.065 0.027 0.15 0.036 0.04 0.052 0.069 0.1 0.087 0.21 0.032 0.11 cov % 63 69 68 91 78 170 57 42 39 69 330 81 110 90 190 410 110 190 75 180 430 57 81 48 180 320 35 68 120 240 46 90 21 22 82 280 150 130 120 130 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 20 21 25 21 22 0.21 0.29 3.2 2 2 1.5 0.19 0.25 0.61 0.6 0.41 0.31 0.15 0.28 0.36 0.27 0.05 0.067 0.16 0.13 0.1 0.19 0.031 0.26 0.43 0.23 0.089 0.13 0.27 0.29 0.19 0.069 0.2 1.5 0.35 0.52 COV % 76 62 61 67 68 170 110 120 92 130 130 92 94 76 90 160 100 97 69 96 140 110 120 84 96 150 58 120 170 180 140 100 75 72 110 62 180 110 80 150 Volatilisation Mean ng/m2/d -27 -20 -30 -43 -30 -7.9 -5.6 -7.4 -11 -8.1 -0.75 -0.53 -0.62 -0.98 -0.72 -0.57 -0.4 -0.43 -0.69 -0.52 -0.38 -0.26 -0.24 -0.39 -0.32 -0.074 -0.053 -0.088 -0.13 -0.086 -0.71 -0.5 -0.58 -0.91 -0.68 -0.24 -0.17 -0.26 -0.39 -0.26 COV % 53 53 53 53 53 52 52 52 52 52 66 66 66 66 66 140 140 140 140 140 140 140 140 140 140 54 54 54 54 54 76 76 76 76 76 180 180 180 180 180 Net Gas Exchange Mean ng/m2/d -7.1 1.8 -4.8 -22 -8 -7.6 -5.3 -4.3 -9.3 -6.6 -0.56 -0.28 -0.01 -0.38 -0.31 -0.26 -0.24 -0.16 -0.33 -0.25 -0.33 -0.2 -0.083 -0.27 -0.22 0.12 -0.022 0.17 0.3 0.14 -0.62 -0.37 -0.31 -0.62 -0.48 -0.17 0.031 1.2 -0.038 0.26 COV % 180 490 220 75 240 52 52 99 56 58 86 120 5400 150 180 350 230 410 290 270 160 190 430 200 190 230 84 180 240 250 84 97 130 100 92 250 1400 140 1900 480 IADN Results to 1996 Page 42 ------- (b) Current-use Pesticides Species Season g-HCH W (lindane) Sp Su F Annual a- W endosulphan Sp Su F Annual b- W endosulphan Sp Su F Annual endosulphan W sulphate Sp Su F Annual Lake Superior 1996 Wet Deposition Mean ng/ni2/d 1 1.6 2.1 0.3 1.3 0.41 0.65 2.9 0.44 1.1 0.077 0.69 5 0.84 1.6 0.12 0.34 1.9 0.067 0.6 COV % 65 180 68 130 140 250 93 72 93 87 250 100 110 19 120 300 81 81 100 100 Dry Deposition Mean ng/ni2/d - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/ni2/d 1.5 3.6 8.7 3.4 4.3 0.42 0.49 16 5.2 5.5 0.034 0.046 1.1 0.4 0.39 - - - - - COV % 100 71 89 64 98 170 97 140 150 190 70 92 150 170 170 - - - - - Volatilisation Mean ng/ni2/d -2.7 _9 -2.9 -4.1 -2.9 -0.0034 -0.0028 -0.0029 -0.0037 -0.0032 -0.00003 -2.1E-05 -3.7E-05 -5.3E-05 -3.5E-05 - - - - - COV % 58 58 58 58 58 120 120 120 120 120 190 190 190 190 190 - - - - - Net Gas Exchange Mean ng/ni2/d -1.1 1.6 5.9 -0.62 1.4 0.41 0.48 16 5.2 5.5 0.034 0.046 1.1 0.4 0.39 - - - - - COV % 150 130 120 300 500 180 97 140 150 190 70 92 150 170 170 - - - - - (c) Banned Organochlorine Commercial Chemicals Species Season HCB W Sp Su F Annual PCB18 W Sp Su F Annual PCB44 W Sp Su F Annual PCB52 W Sp Su F Annual PCB101 W Sp Su F Annual Sum-PCB W Sp Su F Annual Lake Superior 1996 Wet Deposition Mean ng/m2/d 0.046 0.026 0.044 0.045 0.04 0.1 0.024 0.11 0.22 0.11 0.087 0.016 0.048 0.099 0.063 0.17 0.032 0.051 0.085 0.086 0.17 0.032 0.059 0.089 0.087 4.4 0.68 2.3 4.7 3 COV % 260 63 35 40 57 340 35 130 63 130 410 63 93 44 150 510 76 86 89 200 270 45 82 35 110 240 46 110 31 110 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 2.8 2.6 1.9 2.4 2.4 0.096 0.072 0.096 3.8 1 0.17 0.12 0.11 9.2 2.4 0.2 0.21 0.21 7.3 2 0.15 0.18 0.21 4.1 1.2 4.3 6 4.3 6.1 5.2 COV % 69 61 61 59 63 78 72 68 79 97 120 100 85 93 110 81 78 76 76 90 90 86 83 80 100 82 75 110 72 94 Volatilisation Mean ng/m2/d -2.1 -1.4 -1.2 _9 -1.7 -0.67 -0.46 -0.4 -0.65 -0.54 -0.84 -0.59 -0.53 -0.86 -0.7 -0.96 -0.68 -0.64 -1 -0.83 -0.49 -0.34 -0.34 -0.55 -0.43 -23 -16 -12 -20 -18 COV % 180 180 180 180 180 52 52 52 52 52 60 60 60 60 60 58 58 58 58 58 65 65 65 65 65 55 55 55 55 55 Net Gas Exchange Mean ng/m2/d 0.66 1.1 0.75 0.45 0.74 -0.57 -0.39 -0.3 3.2 0.47 -0.67 -0.47 -0.42 8.3 1.7 -0.77 -0.46 -0.42 6.2 1.1 -0.34 -0.16 -0.13 3.5 0.72 -19 -9.8 -7.9 -14 -13 COV % 580 240 290 770 280 53 53 55 89 61 70 69 68 100 73 65 72 74 83 79 85 130 160 89 130 60 72 80 64 70 IADN Results to 1996 Page 43 ------- (d) Currently-Emitted PAHs and Metals Species Season PHEN W Sp Su F Annual PYR W Sp Su F Annual B(b+k)F W Sp Su F Annual B(a)P W Sp Su F Annual I(l,2,3-cd)P W Sp Su F Annual sum-PAH W (UN ECE) Sp Su F Annual Pb W Sp Su F Annual As W Sp Su F Annual Se W Sp Su F Annual Cd W Sp Su F Annual Lake Superior 1996 Wet Deposition Mean ng/m2/d 14 2.7 3.2 6.2 6.4 7.2 2.2 2.9 3.5 3.9 13 3.5 4.4 7.9 7.3 1.7 1.1 1.5 2.2 1.6 5.6 1.7 2.5 3.7 3.4 21 6.4 8.3 14 12 - - - - - - - - - - - - - - - - - - - - cov % 260 52 44 120 180 210 59 88 120 140 160 57 44 69 140 180 68 53 82 87 220 67 66 93 160 120 39 33 49 88 - - - - - - - - - - - - - - - - - - - - Dry Deposition Mean ng/m2/d 7.2 2.8 1.2 2.8 3.5 3.8 3.3 1.1 3.9 3 5.5 4.5 2.1 7.8 5 0.73 1.2 0.57 2.1 1.2 2.3 2.6 1.1 4.6 2.6 8.6 8.3 3.8 15 8.8 - - - - - - - - - - - - - - - - - - - - COV % 140 130 100 130 140 120 130 110 140 140 93 93 73 100 100 110 130 110 130 140 110 140 100 130 140 100 110 100 110 110 - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 150 55 140 150 120 6.6 5 18 19 12 4.1 3.5 2.9 3.2 3.4 1.5 1.3 1 1.4 1.3 0.93 0.78 0.64 0.88 0.81 6.5 5.5 4.6 5.5 5.5 - - - - - - - - - - - - - - - - - - - - COV % 90 80 89 80 100 120 99 92 72 110 58 58 62 65 61 58 58 65 58 60 58 58 70 58 61 40 40 43 42 41 - - - - - - - - - - - - - - - - - - - - Volatilisation Mean ng/m2/d -52 -38 -44 -66 -50 -5 -3.8 -4.7 -6.7 -5.1 -0.12 -0.089 -0.15 -0.22 -0.15 -0.13 -0.096 -0.16 -0.24 -0.16 -2.2E-05 -1.6E-05 -2.7E-05 -0.00004 -2.6E-05 -0.26 -0.19 -0.31 -0.46 -0.3 - - - - - - - - - - - - - - - - - - - - COV % 72 72 72 72 72 120 120 120 120 120 64 64 64 64 64 86 86 86 86 86 110 110 110 110 110 54 54 54 54 54 - - - - - - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d 94 17 96 82 72 1.5 1.2 13 12 7.1 4 3.4 2.7 3 3.3 1.4 1.2 0.88 1.2 1.1 0.93 0.78 0.64 0.88 0.81 6.3 5.3 4.2 5 5.2 - - - - - - - - - - - - - - - - - - - - COV % 130 240 120 130 160 580 500 120 110 180 59 59 63 67 62 60 60 71 63 63 58 58 70 58 61 41 40 44 44 42 - - - - - - - - - - - - - - - - - - - - IADN Results to 1996 Page 44 ------- Table C3: Atmospheric Fluxes to Lake Michigan for 1995 (a) Banned Organochlorine Pesticides Species Season a-HCH W Sp Su F Annual dieldrin W Sp Su F Annual cis- W chlordane Sp Su F Annual trans- W chlordane Sp Su F Annual trans- W nonachlor Sp Su F Annual p,p'-DDD W Sp Su F Annual p,p'-DDE W Sp Su F Annual p,p'-DDT W Sp Su F Annual .ake Michigan 1995 Wet Deposition Mean ng/m2/d 2 1.6 0.33 6.6 2.6 1.2 3 1.9 2.8 2.2 0.38 0.42 0.12 0.55 0.37 0.99 0.27 0.29 0.12 0.42 0.034 0.042 0.025 0.068 0.042 0.086 0.023 0.12 0.072 0.074 0.18 0.76 0.11 0.36 0.35 0.19 0.77 0.16 0.72 0.46 cov % 130 270 250 52 210 21 21 77 62 110 27 290 110 27 300 140 50 89 73 120 12 30 100 60 71 45 110 280 40 220 28 75 59 49 140 110 120 180 78 150 Dry Deposition Mean ng/m2/d 0.29 0.068 0.46 0.042 0.21 1.3 1.2 0.65 0.71 0.97 0.25 0.069 0.091 0.058 0.12 0.15 0.053 0.012 0.034 0.061 0.07 0.029 0.05 0.022 0.046 0.026 0.043 0.21 0.074 0.089 0.079 0.075 0.067 0.039 0.065 0.029 0.019 0.028 0.051 0.032 COV % 150 190 200 140 210 110 110 130 110 110 120 100 140 160 130 100 110 110 160 140 100 120 120 120 120 140 140 130 120 160 110 110 150 100 120 100 100 100 130 130 Gas Exchange Gas Absorption Mean ng/m2/d 28 28 13 20 22 0.3 11 3 1.7 4 0.54 1.4 0.47 0.54 0.74 0.31 0.96 0.3 0.34 0.48 0.078 0.35 0.087 0.099 0.15 0.072 0.096 0.087 0.093 0.087 0.3 1.3 0.67 0.71 0.74 0.56 0.74 0.54 0.28 0.53 COV % 61 65 88 70 69 130 180 140 120 220 78 130 110 90 130 130 140 110 99 130 100 140 120 83 58 120 93 81 110 160 86 120 74 87 120 100 100 100 85 120 Volatilisation Mean ng/m2/d -3.6 -3.2 -8.5 -7.6 -5.7 - - - - - -0.65 -0.58 -0.71 -1 -0.74 -0.51 -0.46 -0.48 -0.75 -0.55 -0.9 -0.8 -0.62 -1.1 -0.85 - - - - - - - - - - - - - - - COV % 51 51 51 51 51 - - - - - 55 55 55 55 55 53 53 53 53 53 68 68 68 68 68 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d 24 25 4.7 13 17 - - - - - -0.11 0.83 -0.24 -0.49 -0.0051 -0.21 0.51 -0.18 -0.41 -0.072 -0.82 -0.45 -0.53 -0.99 -0.7 - - - - - - - - - - - - - - - COV % 64 68 210 93 81 - - - - - 330 200 220 110 3600 190 260 190 92 1600 72 140 76 72 110 - - - - - - - - - - - - - - - IADN Results to 1996 Page 45 ------- (b) Current-use Pesticides Species Season g-HCH W (lindane) Sp Su F Annual a- W endosulphan Sp Su F Annual b- W endosulphan Sp Su F Annual endosulphan W sulphate Sp Su F Annual Wet Deposition Mean ng/m2/d 0.43 1.2 0.81 2.5 1.2 0.84 0.59 0.7 1 0.8 0.35 1 0.9 1.4 0.91 4.6 0.69 0.76 0.72 1.7 cov % 120 120 310 20 130 18 87 230 53 130 66 96 250 30 120 59 81 140 65 97 Dry Deposition Mean ng/m2/d 0.062 0.2 0.11 0.045 0.1 1.1 1.6 1.2 0.83 1.2 0.046 1.5 2.9 0.26 1.2 - - - - - COV % 110 120 140 130 130 100 110 130 150 120 140 160 190 130 230 - - - - - jake Michigan 1995 Gas Exchange Gas Absorption Mean ng/ni2/d 2 2 19 15 3.9 9.9 0.27 23 74 3.5 25 0.11 1.2 4.3 0.21 1.5 - - - - - COV % 65 140 88 72 160 96 190 130 120 240 91 170 130 120 230 - - - - - Volatilisation Mean ng/ni2/d -0.6 -0.54 -1.3 -1.2 -0.9 - - - - - - - - - - - - - - - COV % 50 50 50 50 50 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/ni2/d 1.6 18 14 2.7 9 - - - - - - - - - - - - - - - COV % 76 150 93 90 170 - - - - - - - - - - - - - - - (c) Banned Organochlorine Commercial Chemicals Species Season HCB W Sp Su F Annual PCB18 W Sp Su F Annual PCB44 W Sp Su F Annual PCB52 W Sp Su F Annual PCB101 W Sp Su F Annual Sum-PCB W Sp Su F Annual .ake Michigan 1995 Wet Deposition Mean ng/m2/d 0.064 0.072 0.049 0.076 0.065 0.13 0.11 0.16 0.088 0.12 0.12 0.084 0.066 0.076 0.086 0.22 0.12 0.11 0.12 0.14 0.14 0.098 0.066 0.088 0.098 4.7 4.1 3.6 2.5 3.7 COV % 27 22 35 44 72 19 46 45 92 100 23 68 76 49 130 13 55 47 64 180 35 42 70 65 120 18 27 44 80 87 Dry Deposition Mean ng/m2/d 0.0097 0.018 0.03 0.009 0.017 0.082 0.041 0.049 0.042 0.053 0.088 0.018 0.03 0.065 0.05 0.13 0.08 0.11 0.061 0.093 0.2 0.038 0.04 0.025 0.075 3.8 1.8 1.2 0.95 1.9 COV % 140 110 150 120 140 100 100 110 100 110 150 130 100 140 150 130 100 120 100 120 170 100 110 100 210 140 110 100 100 140 Gas Exchange Gas Absorption Mean ng/m2/d 3.4 3.7 0.69 1.2 2.3 0.16 0.33 0.072 0.2 0.19 0.16 0.64 0.26 0.42 0.37 0.27 0.56 0.16 0.43 0.36 0.15 0.32 0.079 0.2 0.19 3.2 8.6 1.8 5 4.7 COV % 59 65 76 65 72 68 110 69 96 100 100 84 150 150 140 66 100 67 98 98 71 110 63 110 100 87 110 80 120 110 Volatilisation Mean ng/m2/d -2.1 -1.9 -1.3 -2.3 -1.9 -1.5 -1.3 -0.93 -1.7 -1.3 -1.4 -1.2 -0.96 -1.7 -1.3 -0.22 -0.2 -0.17 -0.28 -0.22 -0.63 -0.56 -0.5 -0.83 -0.63 -22 -19 -15 -26 -20 COV % 53 53 53 53 53 56 56 56 56 56 52 52 52 52 52 150 150 150 150 150 52 52 52 52 52 50 50 50 50 50 Net Gas Exchange Mean ng/m2/d 1.3 1.9 -0.58 -1.1 0.39 -1.3 -0.97 -0.86 -1.5 -1.2 -1.2 -0.58 -0.7 -1.2 -0.93 0.047 0.37 -0.0047 0.16 0.14 -0.48 -0.23 -0.42 -0.63 -0.44 -18 -11 -13 -21 -16 COV % 99 97 92 78 1500 58 70 57 59 59 53 94 76 71 70 740 170 5400 350 360 55 160 53 62 64 52 96 51 57 57 IADN Results to 1996 Page 46 ------- (d) Currently-Emitted PAHs and Metals Species Season PHEN W Sp Su F Annual PYR W Sp Su F Annual B(b+k)F W Sp Su F Annual B(a)P W Sp Su F Annual I(l,2,3-cd)P W Sp Su F Annual sum-PAH W (UN ECE) Sp Su F Annual Pb W Sp Su F Annual As W Sp Su F Annual Se W Sp Su F Annual Cd W Sp Su F Annual .ake Michigan 1995 Wet Deposition Mean ng/m2/d 22 14 7.3 25 17 20 17 4.3 24 16 32 24 7.8 27 22 9.1 7 2.4 12 7.7 16 9.8 3.1 19 12 58 41 13 58 42 - - - - - - - - - - - - - - - - - - - - cov % 83 66 37 74 190 98 32 99 57 150 70 36 62 45 120 76 36 84 35 140 83 55 110 26 110 48 27 48 26 73 - - - - - - - - - - - - - - - - - - - - Dry Deposition Mean ng/m2/d 5.6 3 3.1 3.8 3.9 6.2 4.5 3.1 4.2 4.5 15 7.7 7.3 7.7 9.4 1.9 2.4 1.2 1.6 1.8 6.7 2.4 1.8 3.6 3.6 24 12 10 13 15 - - - - - - - - - - - - - - - - - - - - COV % 110 110 110 130 110 100 120 100 120 110 84 83 75 110 95 100 130 100 120 120 100 110 110 130 120 100 100 100 110 110 - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 250 130 70 110 140 13 9.5 7.1 11 10 3.7 3.3 3.6 3.6 3.5 1.4 1.3 1.2 1.3 1.3 0.85 0.81 0.83 0.87 0.84 5.9 5.4 5.6 5.8 5.7 - - - - - - - - - - - - - - - - - - - - COV % 70 130 81 80 93 120 190 95 77 120 59 61 66 61 69 59 60 72 61 66 59 60 72 59 64 40 41 46 41 47 - - - - - - - - - - - - - - - - - - - - Volatilisation Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - IADN Results to 1996 Page 47 ------- Table C4: Atmospheric Fluxes to Lake Michigan for 1996 (a) Banned Organochlorine Pesticides Species Season a-HCH W Sp Su F Annual dieldrin W Sp Su F Annual cis- W chlordane Sp Su F Annual trans- W chlordane Sp Su F Annual trans- W nonachlor Sp Su F Annual p,p'-DDD W Sp Su F Annual p,p'-DDE W Sp Su F Annual p,p'-DDT W Sp Su F Annual .ake Michigan 1996 Wet Deposition Mean ng/m2/d 1.7 0.0082 0.82 0.37 0.71 3.1 0.41 1.6 0.48 1.4 0.3 0.0082 0.096 0.33 0.18 0.18 0.49 0.95 0.19 0.45 0.016 0.03 0.11 0.025 0.045 0.098 0.0055 0.1 0.13 0.084 0.15 0.13 0.16 0.31 0.19 0.089 0.19 0.65 0.78 0.43 cov % 120 150 180 120 260 87 62 38 180 120 97 120 150 110 190 190 140 88 140 130 31 - 130 58 130 100 110 110 50 110 100 79 58 32 79 56 190 330 88 220 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 23 22 18 13 19 0.48 0.75 3.7 2.8 1.9 0.31 0.5 0.65 0.63 0.52 0.26 0.31 0.4 0.49 0.36 0.074 0.14 0.13 0.12 0.11 0.46 0.035 0.22 0.65 0.34 0.17 0.73 0.7 0.9 0.62 0.11 0.17 1.5 0.71 0.61 COV % 66 61 72 68 72 110 160 89 120 150 87 88 87 100 120 180 87 89 110 130 96 74 99 110 120 120 58 110 130 180 98 120 82 130 130 81 110 88 130 160 Volatilisation Mean ng/m2/d -3.3 -2.9 -6.3 -6.9 -4.9 - - - - - -0.64 -0.56 -0.62 -0.9 -0.68 -0.51 -0.45 -0.43 -0.64 -0.51 -0.96 -0.82 -0.57 -0.92 -0.82 - - - - - - - - - - - - - - - COV % 51 51 51 51 51 - - - - - 55 55 55 55 55 53 53 53 53 53 68 68 68 68 68 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d 20 19 11 5.8 14 - - - - - -0.33 -0.055 0.031 -0.27 -0.15 -0.25 -0.14 -0.034 -0.15 -0.14 -0.88 -0.69 -0.44 -0.81 -0.7 - - - - - - - - - - - - - - - COV % 71 64 95 110 86 - - - - - 94 710 1500 220 2200 190 170 880 350 840 71 76 82 74 410 - - - - - - - - - - - - - - - IADN Results to 1996 Page 48 ------- (b) Current-use Pesticides Species Season g-HCH W (lindane) Sp Su F Annual a- W endosulphan Sp Su F Annual b- W endosulphan Sp Su F Annual endosulphan W sulphate Sp Su F Annual Wet Deposition Mean ng/m2/d 0.69 0.03 0.5 0.036 0.31 0.35 0.085 1.9 0.28 0.65 0.33 0.011 1.1 0.033 0.37 0.24 0.016 0.89 0.18 0.33 cov % 71 190 310 110 290 110 150 190 280 230 77 230 390 90 460 70 - 280 270 300 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - jake Michigan 1996 Gas Exchange Gas Absorption Mean ng/ni2/d 2 2 5.8 12 3.3 5.9 0.84 1.3 54 12 17 0.068 0.26 2.7 3.9 1.7 - - - - - COV % 72 88 100 85 140 120 170 110 200 230 100 140 160 260 300 - - - - - Volatilisation Mean ng/ni2/d -0.56 -0.5 -0.98 -1.1 -0.78 - - - - - - - - - - - - - - - COV % 50 50 50 50 50 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/ni2/d 1.7 5.3 11 2.2 5.1 - - - - - - - - - - - - - - - COV % 86 93 110 110 160 - - - - - - - - - - - - - - - (c) Banned Organochlorine Commercial Chemicals Species Season HCB W Sp Su F Annual PCB18 W Sp Su F Annual PCB44 W Sp Su F Annual PCB52 W Sp Su F Annual PCB101 W Sp Su F Annual Sum-PCB W Sp Su F Annual .ake Michigan 1996 Wet Deposition Mean ng/m2/d 0.058 0.014 0.057 0.044 0.043 0.14 0.016 0.087 0.073 0.08 0.075 0.014 0.031 0.065 0.046 0.19 0.033 0.092 0.1 0.1 0.12 0.014 0.048 0.076 0.064 3 0.48 3 2.6 2.3 COV % 69 61 55 35 48 100 73 46 15 65 160 120 72 46 75 140 96 54 24 55 81 81 83 58 93 110 80 54 37 44 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 2.8 3.4 1.4 1.5 2 2 0.15 0.17 0.21 0.17 0.18 0.11 0.13 0.2 0.4 0.21 0.24 0.31 0.39 0.29 0.31 0.11 0.17 0.2 0.16 0.16 3 4.2 5.7 4.6 4.4 COV % 71 61 75 62 74 89 79 120 100 150 80 100 110 190 190 80 74 90 110 120 79 80 84 110 130 83 83 100 110 140 Volatilisation Mean ng/m2/d -2.3 -2 -1.2 _9 -1.9 -1.6 -1.4 -0.87 -1.4 -1.3 -1.5 -1.3 -0.89 -1.4 -1.3 -0.23 -0.2 -0.15 -0.24 -0.21 -0.65 -0.56 -0.45 -0.71 -0.59 -23 -20 -14 -22 -20 COV % 53 53 53 53 53 56 56 56 56 56 52 52 52 52 52 150 150 150 150 150 52 52 52 52 52 50 50 50 50 50 Net Gas Exchange Mean ng/m2/d 0.5 1.4 0.16 -0.48 0.39 -1.4 -1.2 -0.66 -1.3 -1.1 -1.4 -1.1 -0.68 -1 -1 0.011 0.1 0.24 0.058 0.1 -0.54 -0.39 -0.25 -0.55 -0.43 -20 -16 -8 -17 -15 COV % 300 100 490 140 340 58 58 69 59 66 52 53 60 92 80 3400 330 160 770 280 54 60 78 61 89 51 53 80 57 75 IADN Results to 1996 Page 49 ------- (d) Currently-Emitted PAHs and Metals Species Season PHEN W Sp Su F Annual PYR W Sp Su F Annual B(b+k)F W Sp Su F Annual B(a)P W Sp Su F Annual I(l,2,3-cd)P W Sp Su F Annual sum-PAH W (UN ECE) Sp Su F Annual Pb W Sp Su F Annual As W Sp Su F Annual Se W Sp Su F Annual Cd W Sp Su F Annual jake Michigan 1996 Wet Deposition Mean ng/m2/d 36 1.7 3.4 1.1 10 23 1.4 2 0.85 6.8 30 4.4 11 3.7 12 10 1.5 3.4 0.82 4 15 2.5 5.8 1.7 6.3 55 8.4 20 6.2 23 - - - - - - - - - - - - - - - - - - - - cov % 55 140 230 92 340 65 110 150 130 340 47 - 31 180 140 84 73 63 220 160 38 - 66 250 160 33 - 29 130 89 - - - - - - - - - - - - - - - - - - - - Dry Deposition Mean ng/m2/d 10 5 1.7 2.9 5 9.7 6 1.5 3.3 5.1 19 8.9 2.6 6.5 9.2 2.7 2.5 0.65 1.9 1.9 7.7 6.4 1.4 3.5 4.8 29 18 4.5 12 16 - - - - - - - - - - - - - - - - - - - - COV % 110 120 110 110 130 110 130 110 130 140 95 95 73 85 110 130 120 100 120 130 120 140 100 110 130 110 110 100 100 110 - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/ni2/d 240 80 160 94 140 14 5.7 22 8.7 12 6.9 3.9 2.6 3.1 4.1 2 1.7 1 1.5 1.5 0.94 1.3 0.65 0.98 0.96 9.8 6.9 4.3 5.6 6.7 - - - - - - - - - - - - - - - - - - - - COV % 87 76 160 90 150 100 91 120 100 150 77 58 61 70 68 66 74 61 71 68 58 100 61 69 82 56 42 41 45 45 - - - - - - - - - - - - - - - - - - - - Volatilisation Mean ng/ni2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/ni2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - IADN Results to 1996 Page 50 ------- Table C5: Atmospheric Fluxes to Lake Huron for 1995 (a) Banned Organochlorine Pesticides Species Season a-HCH W Sp Su F Annual dieldrin W Sp Su F Annual cis- W chlordane Sp Su F Annual trans- W chlordane Sp Su F Annual trans- W nonachlor Sp Su F Annual p,p'-DDD W Sp Su F Annual p,p'-DDE W Sp Su F Annual p,p'-DDT W Sp Su F Annual Lake Huron 1995 Wet Deposition Mean ng/m2/d 7.8 11 6.9 15 10 0.17 1.8 0.62 0.93 0.88 - - - - - - - - - - - - - - - 0.15 0.17 0.13 0.25 0.18 0 0.76 0.58 0.21 0.44 0 0.21 1.2 0.29 0.47 cov % 160 140 120 88 140 220 88 87 160 200 - - - - - - - - - - - - - - - 310 400 60 550 400 0 140 220 410 190 0 380 240 550 1200 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 13 13 12 12 13 0.87 0.8 1.9 1.9 1.4 0.28 0.2 0.28 0.43 0.3 0.24 0.16 0.16 0.26 0.21 0.098 0.093 0.084 0.14 0.1 0.024 0.037 0.082 0.044 0.047 0 0.41 0.26 0.45 0.4 0 0.098 0.34 0.23 0.2 COV % 58 63 67 62 67 78 77 95 130 130 - 64 94 120 120 72 67 90 120 110 80 66 99 120 130 - 100 - 64 87 0 61 71 81 78 0 68 76 100 110 Volatilisation Mean ng/m2/d -9.9 -7.9 -21 -21 -15 - - - - - -0.49 -0.35 -0.49 -0.85 -0.55 -0.45 -0.32 -0.38 -0.72 -0.47 -0.69 -0.45 -0.39 -0.9 -0.61 - - - - - - - - - - - - - - - COV % 54 54 54 54 54 - - - - - 53 53 53 53 53 54 54 54 54 54 52 52 52 52 52 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d 3.1 4.7 -8.6 -8.4 -2.3 - - - - - -0.21 -0.15 -0.21 -0.42 -0.25 -0.2 -0.16 -0.22 -0.46 -0.26 -0.59 -0.36 -0.31 -0.77 -0.51 - - - - - - - - - - - - - - - COV % 290 160 180 180 1100 - - - - - - 170 190 180 330 190 150 130 130 180 93 94 97 91 100 - - - - - - - - - - - - - - - IADN Results to 1996 Page 51 ------- (b) Current-use Pesticides Species Season g-HCH W (lindane) Sp Su F Annual a- W endosulphan Sp Su F Annual b- W endosulphan Sp Su F Annual endosulphan W sulphate Sp Su F Annual Lake Huron 1995 Wet Deposition Mean ng/ni2/d 0.93 9.8 3.1 5.8 4.9 0.27 5.1 3 0.61 2.2 1.3 4.8 4.6 1.7 3.1 - - - - - COV % 110 68 82 130 100 180 170 65 260 170 100 98 74 120 97 - - - - - Dry Deposition Mean ng/ni2/d - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/ni2/d 2 3 4.9 2.6 3.1 1.3 1.5 12 2.8 4.3 - 0.14 1.6 0.32 - - - - - - COV % 58 81 82 72 98 59 84 110 92 170 - 100 130 120 - - - - - - Volatilisation Mean ng/ni2/d -1.2 -0.95 -2.3 -2.3 -1.7 - - - - - - - - - - - - - - - COV % 55 55 55 55 55 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/ni2/d 0.83 2 2.6 0.38 1.5 - - - - - - - - - - - - - - - COV % 140 110 140 540 170 - - - - - - - - - - - - - - - (c) Banned Organochlorine Commercial Chemicals Species Season HCB W Sp Su F Annual PCB18 W Sp Su F Annual PCB44 W Sp Su F Annual PCB52 W Sp Su F Annual PCB101 W Sp Su F Annual Sum-PCB W Sp Su F Annual Lake Huron 1995 Wet Deposition Mean ng/m2/d 0.13 0.17 0.3 0.05 0.16 - - - - - - - - - - - - - - - - - - - - - - - - - COV % 160 99 210 130 210 - - - - - - - - - - - - - - - - - - - - - - - - - Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 3.6 2.3 0.33 1.8 2 0 0.9 0.26 0.71 0.69 0.18 0.083 0.061 0.15 0.12 0 0.19 0.11 0.24 0.18 0 0.073 0.052 0.1 0.08 6.2 4.8 1.8 4.4 4.3 COV % 59 61 64 61 66 0 59 61 75 67 63 63 71 93 83 0 63 68 97 81 0 61 76 110 97 65 63 63 77 68 Volatilisation Mean ng/m2/d -4.4 -2.9 -2.2 -5.1 -3.6 -1.6 -1 -0.83 -1.9 -1.3 -1 -0.67 -0.6 -1.3 -0.89 -0.56 -0.39 -0.37 -0.76 -0.52 -0.45 -0.31 -0.32 -0.65 -0.43 -17 -12 -10 -22 -15 COV % 55 55 55 55 55 52 52 52 52 52 51 51 51 51 51 51 51 51 51 51 50 50 50 50 50 51 51 51 51 51 Net Gas Exchange Mean ng/m2/d -0.72 -0.52 -1.9 -3.3 -1.6 -0.66 -0.13 -0.57 -1.2 -0.63 -0.82 -0.59 -0.53 -1.1 -0.77 -0.37 -0.2 -0.26 -0.52 -0.34 -0.36 -0.24 -0.26 -0.55 -0.35 -11 -6.9 -8.3 -17 -11 COV % 530 420 95 120 130 200 540 100 120 140 89 78 77 78 79 120 130 99 110 110 89 81 77 78 82 120 110 84 86 91 IADN Results to 1996 Page 52 ------- (d) Currently-Emitted PAHs and Metals Species Season PHEN W Sp Su F Annual PYR W Sp Su F Annual B(b+k)F W Sp Su F Annual B(a)P W Sp Su F Annual I(l,2,3-cd)P W Sp Su F Annual sum-PAH W (UN ECE) Sp Su F Annual Pb W Sp Su F Annual As W Sp Su F Annual Se W Sp Su F Annual Cd W Sp Su F Annual Lake Huron 1995 Wet Deposition Mean ng/m2/d 14 12 3.6 15 11 11 10 2.5 16 10 21 23 18 51 28 13 16 11 23 16 27 33 23 44 32 60 73 53 120 76 840 730 290 910 690 140 110 51 97 100 130 130 58 190 130 90 50 41 78 65 cov % 79 140 53 360 380 88 110 79 190 400 220 290 43 300 240 310 380 60 520 380 310 380 60 580 390 170 210 34 270 200 56 68 57 71 180 85 61 54 17 210 58 64 80 34 190 75 44 43 14 180 Dry Deposition Mean ng/m2/d 3.3 4.6 1.6 9 2.9 2.6 4 1.9 2.8 2.8 - - - - - - - - - - 3.8 3.1 3.3 3.6 3.5 - - - - - 590 430 160 210 350 18 44 21 47 33 - - 5.5 16 5.3 6.2 16 3.5 5.4 7.7 COV % 120 130 110 110 130 140 140 120 140 140 - - - - - - - - - - 130 130 130 130 130 - - - - - 110 160 160 190 150 170 150 180 200 190 - - 170 250 360 160 170 260 200 210 Gas Exchange Gas Absorption Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Volatilisation Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - IADN Results to 1996 Page 53 ------- Table C6: Atmospheric Fluxes to Lake Huron for 1996 (a) Banned Organochlorine Pesticides Species Season a-HCH W Sp Su F Annual dieldrin W Sp Su F Annual cis- W chlordane Sp Su F Annual trans- W chlordane Sp Su F Annual trans- W nonachlor Sp Su F Annual p,p'-DDD W Sp Su F Annual p,p'-DDE W Sp Su F Annual p,p'-DDT W Sp Su F Annual Lake Huron 1996 Wet Deposition Mean ng/m2/d 13 12 2.7 2.5 7.4 1.2 1 3.2 2.1 1.9 - - - - - - - - - - - - - - - 0.29 0.23 0.22 0.49 0.31 0 0.14 0.13 0.35 0.36 0 0.45 0.26 0.18 0.82 cov % 94 190 63 100 240 410 210 140 92 160 - - - - - - - - - - - - - - - 280 530 2500 260 960 0 170 2600 92 1900 0 210 2500 36 2500 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 9.2 12 7.9 8.9 9.5 0.73 0.87 1.5 1.9 1.2 0.14 0.26 0.25 0.36 0.25 0.14 0.18 0.14 0.32 0.2 0.057 0.12 0.076 0.12 0.094 0.036 0.039 0.034 0.047 0.039 0 0.33 0.17 0.33 0.29 0 0.15 0.16 0.21 0.14 COV % 68 62 62 61 66 110 100 84 74 100 96 84 79 83 97 110 84 97 74 110 88 88 81 75 100 70 74 89 77 84 0 89 100 84 96 0 100 97 81 100 Volatilisation Mean ng/m2/d -9.5 -7.1 -15 -18 -12 - - - - - -0.48 -0.32 -0.42 -0.59 -0.45 -0.44 -0.29 -0.33 -0.49 -0.39 -0.71 -0.42 -0.35 -0.56 -0.51 - - - - - - - - - - - - - - - COV % 54 54 54 54 54 - - - - - 53 53 53 53 53 54 54 54 54 54 52 52 52 52 52 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d -0.25 4.8 -7.6 -8.6 -2.9 - - - - - -0.34 -0.059 -0.17 -0.23 -0.2 -0.3 -0.11 -0.19 -0.17 -0.19 -0.65 -0.31 -0.28 -0.43 -0.42 - - - - - - - - - - - - - - - COV % 3500 140 150 150 360 - - - - - 120 460 190 200 310 130 220 140 230 200 86 100 96 96 100 - - - - - - - - - - - - - - - IADN Results to 1996 Page 54 ------- (b) Current-use Pesticides Species Season g-HCH W (lindane) Sp Su F Annual a- W endosulphan Sp Su F Annual b- W endosulphan Sp Su F Annual endosulphan W sulphate Sp Su F Annual Lake Huron 1996 Wet Deposition Mean ng/ni2/d 1.9 8.8 3.8 2.5 4.3 0.92 0.92 2.6 0.99 1.4 0.77 2.4 4.6 2.2 2.5 - - - - - COV % 94 110 140 63 160 94 82 220 68 230 130 140 110 60 140 - - - - - Dry Deposition Mean ng/ni2/d - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/ni2/d 1.3 3.2 4.4 2 2.7 0.99 1.2 5.2 3.2 2.7 0.025 0.13 0.53 0.24 0.23 - - - - - COV % 66 93 86 66 110 68 96 96 130 140 - 96 89 130 120 - - - - - Volatilisation Mean ng/ni2/d -1.1 -0.85 -1.7 -1.9 -1.4 - - - - - - - - - - - - - - - COV % 55 55 55 55 55 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/ni2/d 0.18 2.4 2.7 0.098 1.3 - - - - - - - - - - - - - - - COV % 600 120 130 1600 190 - - - - - - - - - - - - - - - (c) Banned Organochlorine Commercial Chemicals Species Season HCB W Sp Su F Annual PCB18 W Sp Su F Annual PCB44 W Sp Su F Annual PCB52 W Sp Su F Annual PCB101 W Sp Su F Annual Sum-PCB W Sp Su F Annual Lake Huron 1996 Wet Deposition Mean ng/m2/d 0.23 0.0077 0.0072 0.0049 0.062 - - - - - - - - - - - - - - - - - - - - - - - - - COV % 180 350 2800 51 490 - - - - - - - - - - - - - - - - - - - - - - - - - Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 3.3 2.5 0.49 0.94 1.8 0 0.51 0.14 0.31 0.46 0.11 0.093 0.046 0.1 0.088 0 0.22 0.11 0.24 0.19 0 0.1 0.057 0.081 0.079 4.1 2.7 1.1 2.7 2.6 COV % 61 61 67 64 65 0 77 62 97 77 64 74 64 90 86 0 77 67 76 82 0 78 63 70 80 61 71 65 90 81 Volatilisation Mean ng/m2/d -4.6 -2.7 -2 -3.2 -3.1 -1.6 -0.99 -0.75 -1.2 -1.1 -1 -0.64 -0.53 -0.83 -0.76 -0.58 -0.37 -0.33 -0.5 -0.44 -0.45 -0.29 -0.28 -0.43 -0.36 -18 -11 -9 -14 -13 COV % 55 55 55 55 55 52 52 52 52 52 51 51 51 51 51 51 51 51 51 51 50 50 50 50 50 51 51 51 51 51 Net Gas Exchange Mean ng/m2/d -1.3 -0.23 -1.5 -2.2 -1.3 -0.77 -0.47 -0.6 -0.88 -0.68 -0.92 -0.54 -0.49 -0.73 -0.67 -0.39 -0.15 -0.22 -0.26 -0.25 -0.38 -0.19 -0.22 -0.34 -0.28 -14 -8.4 -7.8 -11 -10 COV % 310 910 110 110 140 170 150 92 100 110 81 80 76 79 78 110 180 110 140 130 84 95 79 79 84 96 90 80 86 86 IADN Results to 1996 Page 55 ------- (d) Currently-Emitted PAHs and Metals Species Season PHEN W Sp Su F Annual PYR W Sp Su F Annual B(b+k)F W Sp Su F Annual B(a)P W Sp Su F Annual I(l,2,3-cd)P W Sp Su F Annual sum-PAH W (UN ECE) Sp Su F Annual Pb W Sp Su F Annual As W Sp Su F Annual Se W Sp Su F Annual Cd W Sp Su F Annual Lake Huron 1996 Wet Deposition Mean ng/m2/d 31 13 14 14 18 36 13 6.3 8.4 16 - - - - - - - - - - 44 35 38 28 36 - - - - - 1400 1400 320 250 840 240 79 100 66 120 280 79 100 120 140 100 160 65 39 91 cov % 190 160 520 77 290 190 160 1100 90 290 - - - - - - - - - - 320 390 2600 37 1500 - - - - - 160 1100 210 82 1600 97 74 200 46 140 210 2700 150 14 90 120 1600 150 27 1900 Dry Deposition Mean ng/m2/d 9 2.9 2.8 6.2 5.2 7.4 4.1 4.9 7.4 5.9 15 8.7 8.1 16 12 6.1 3.3 3.8 5.7 4.7 13 5.4 5.7 13 9.3 34 17 18 35 26 650 660 230 790 580 160 280 16 78 130 14 80 1.9 100 49 14 14 2.8 26 14 COV % 110 120 130 130 130 110 110 120 130 120 83 85 93 110 99 120 120 120 140 130 100 110 130 140 130 100 100 110 110 110 170 150 130 130 150 210 240 130 140 240 210 260 310 160 230 240 210 180 170 190 Gas Exchange Gas Absorption Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Volatilisation Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - IADN Results to 1996 Page 56 ------- Table C7: Atmospheric Fluxes to Lake Erie for 1995 (a) Banned Organochlorine Pesticides Species Season a-HCH W Sp Su F Annual dieldrin W Sp Su F Annual cis- W chlordane Sp Su F Annual trans- W chlordane Sp Su F Annual trans- W nonachlor Sp Su F Annual p,p'-DDD W Sp Su F Annual p,p'-DDE W Sp Su F Annual p,p'-DDT W Sp Su F Annual Lake Erie 1995 Wet Deposition Mean ng/m2/d 9.5 1 0.46 1.3 3.1 2 0.81 0.87 1.6 1.3 2.6 0.34 0.51 0.93 1.1 5.6 0.64 1 0.38 1.9 0.11 0.035 0.074 0.068 0.072 0.43 0.065 0.097 0.12 0.18 2.1 0.31 0.28 0.59 0.83 1.5 0.2 0.52 4 1.5 cov % 190 93 110 220 280 41 22 23 86 180 11 130 68 93 110 95 140 82 100 470 180 130 60 19 110 31 140 89 170 1100 74 130 56 120 140 19 31 83 310 280 Dry Deposition Mean ng/m2/d 0.23 0.031 0.1 0.025 0.096 1.4 2.1 0.58 0.72 1.2 1 0.15 0.023 0.22 0.35 0.25 0.14 0.049 0.072 0.13 0.19 0.078 1.3 0.18 0.43 0.18 0.073 0.21 0.065 0.13 0.21 0.12 0.12 0.064 0.13 0.023 0.45 0.11 0.046 0.16 COV % 160 150 180 130 190 120 130 140 100 130 160 110 150 140 200 130 100 170 110 130 120 100 180 170 250 110 120 120 130 130 120 110 110 100 120 140 190 160 140 240 Gas Exchange Gas Absorption Mean ng/m2/d 28 28 22 34 28 1.1 3.9 3.3 4 3.1 1.7 1.4 0.83 1.2 1.3 0.94 1.1 0.47 0.85 0.84 0.21 0.3 0.11 0.25 0.22 0.42 0.19 0.19 0.16 0.24 1.2 1.9 1.2 1.9 1.6 0.68 1 1.3 1.6 1.1 COV % 68 62 66 65 67 83 110 110 100 140 78 84 84 83 100 81 93 80 90 100 96 96 85 90 130 68 100 91 120 180 120 91 92 79 120 160 99 72 83 100 Volatilisation Mean ng/m2/d -8.6 -8.3 -22 -21 -15 -11 -10 -15 -22 -15 -0.54 -0.48 -0.52 -0.84 -0.6 -0.5 -0.43 -0.4 -0.69 -0.5 -0.47 -0.38 -0.26 -0.5 -0.4 - - - - - - - - - - - - - - - COV % 60 60 60 60 60 59 59 59 59 59 56 56 56 56 56 54 54 54 54 54 52 52 52 52 52 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d 19 20 -0.13 13 13 -10 -6.5 -12 -18 -12 1.2 0.96 0.31 0.37 0.7 0.45 0.69 0.069 0.16 0.34 -0.26 -0.074 -0.16 -0.25 -0.19 - - - - - - - - - - - - - - - COV % 77 78 14000 170 130 96 140 110 110 120 96 120 220 280 170 160 140 580 490 230 150 470 130 150 160 - - - - - - - - - - - - - - - IADN Results to 1996 Page 57 ------- (b) Current-use Pesticides Species Season g-HCH W (lindane) Sp Su F Annual a- W endosulphan Sp Su F Annual b- W endosulphan Sp Su F Annual endosulphan W sulphate Sp Su F Annual Lake Erie 1995 Wet Deposition Mean ng/m2/d 2.6 2.2 0.38 0.37 1.4 1.5 0.85 1.3 0.24 0.98 1.9 1.3 0.64 0.15 0.99 7.8 0.7 1.3 0.25 2.5 cov % 190 96 77 230 200 170 110 200 280 190 75 66 73 330 140 220 81 110 55 300 Dry Deposition Mean ng/m2/d 0.054 0.12 0.044 0.04 0.064 1.5 1.8 3.4 0.88 1.9 0.61 0.82 4.6 0.45 1.6 - - - - - COV % 140 140 180 130 140 110 130 150 120 150 160 120 160 130 220 - - - - - Gas Exchange Gas Absorption Mean ng/ni2/d 3.1 11 9.3 6.1 7.4 1.5 9.8 110 10 32 0.64 2.4 9 0.83 3.2 - - - - - COV % 80 120 70 67 110 79 130 90 120 200 77 170 98 130 180 - - - - - Volatilisation Mean ng/ni2/d -1.6 -1.5 -3.8 -3.5 -2.6 -0.033 -0.03 -0.035 -0.041 -0.035 -0.00064 -0.00063 -0.0026 -0.0019 -0.0014 - - - - - COV % 110 110 110 110 110 100 100 100 100 100 99 99 99 99 99 - - - - - Net Gas Exchange Mean ng/ni2/d 1.5 9.6 5.5 2.6 4.8 1.5 9.8 110 10 32 0.64 2.4 9 0.83 3.2 - - - - - COV % 160 140 120 180 160 62 130 90 120 200 58 170 98 130 180 - - - - - (c) Banned Organochlorine Commercial Chemicals Species Season HCB W Sp Su F Annual PCB18 W Sp Su F Annual PCB44 W Sp Su F Annual PCB52 W Sp Su F Annual PCB101 W Sp Su F Annual Sum-PCB W Sp Su F Annual Lake Erie 1995 Wet Deposition Mean ng/m2/d 0.18 0.033 0.037 0.057 0.078 0.29 0.057 0.17 0.075 0.15 0.22 0.069 0.083 0.039 0.1 0.37 0.092 0.16 0.11 0.18 0.34 0.065 0.095 0.078 0.14 15 2.6 4.7 2.2 6.2 COV % 12 51 27 88 91 120 32 34 100 79 56 27 40 38 97 61 27 23 72 91 64 30 29 96 94 36 28 28 97 80 Dry Deposition Mean ng/m2/d 0.044 0.019 0.016 0.014 0.023 0.11 0.047 0.063 0.037 0.064 0.22 0.055 0.099 0.12 0.12 0.3 0.096 0.1 0.064 0.14 0.43 0.05 0.051 0.049 0.14 8.2 9 1.7 1.5 3.4 COV % 100 110 100 100 110 100 100 100 100 110 180 100 110 160 160 160 100 100 110 170 180 100 100 110 250 150 100 100 100 180 Gas Exchange Gas Absorption Mean ng/m2/d 4.6 3.3 0.79 1.6 2.6 0.48 0.49 0.24 0.31 0.38 0.85 1 0.84 0.93 0.91 0.76 0.96 0.91 0.82 0.86 0.38 0.47 0.39 0.37 0.41 12 12 9 9.3 11 COV % 65 62 61 61 64 86 72 68 79 94 120 76 72 110 120 82 69 81 80 120 88 71 84 82 130 86 70 72 78 110 Volatilisation Mean ng/m2/d -3.3 -2.6 -1.6 -3.2 -2.7 -3.4 -2.6 -1.7 -3.3 -2.8 -2.4 -1.9 -1.4 -2.6 -2.1 -2 -1.6 -1.2 -2.3 -1.8 -1 -0.87 -0.69 -1.3 -0.97 -40 -32 -23 -42 -34 COV % 280 280 280 280 280 65 65 65 65 65 59 59 59 59 59 85 85 85 85 85 96 96 96 96 96 82 82 82 82 82 Net Gas Exchange Mean ng/m2/d 1.2 0.77 -0.83 -1.6 -0.11 -2.9 -2.2 -1.5 -3 -2.4 -1.5 -0.91 -0.53 -1.6 -1.2 -1.2 -0.67 -0.33 -1.4 -0.92 -0.66 -0.39 -0.3 -0.89 -0.56 -29 -20 -14 -33 -24 COV % 340 460 260 260 630 110 110 110 100 110 150 180 210 140 180 160 240 380 160 320 160 220 240 150 280 140 160 160 130 160 IADN Results to 1996 Page 58 ------- (d) Currently-Emitted PAHs and Metals Species Season PHEN W Sp Su F Annual PYR W Sp Su F Annual B(b+k)F W Sp Su F Annual B(a)P W Sp Su F Annual I(l,2,3-cd)P W Sp Su F Annual sum-PAH W (UN ECE) Sp Su F Annual Pb W Sp Su F Annual As W Sp Su F Annual Se W Sp Su F Annual Cd W Sp Su F Annual Lake Erie 1995 Wet Deposition Mean ng/m2/d 170 6.9 14 35 57 100 8 12 31 39 160 16 25 41 60 52 4.8 8.5 15 20 100 6.8 8.6 21 35 310 27 42 78 120 - - - - - - - - - - - - - - - - - - - - cov % 59 65 93 190 170 59 68 140 180 130 50 52 85 84 99 59 73 110 110 110 59 58 110 110 150 34 36 62 60 70 - - - - - - - - - - - - - - - - - - - - Dry Deposition Mean ng/m2/d 32 13 8.1 16 17 36 21 13 23 23 110 47 42 50 62 15 10 8 11 11 41 13 13 27 23 160 70 63 88 96 - - - - - - - - - - - - - - - - - - - - COV % 110 120 130 110 120 120 110 120 100 120 99 80 120 92 97 120 100 130 100 110 130 110 140 110 130 110 100 120 100 110 - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 1000 570 730 590 720 120 52 120 99 98 11 11 3.7 5.5 7.8 2.6 3.5 1.4 2 2.4 2 2 1.2 0.94 1.3 1.4 16 16 5.9 8.7 12 - - - - - - - - - - - - - - - - - - - - COV % 68 82 69 90 95 120 100 69 140 110 100 88 64 64 93 71 84 68 68 82 100 69 68 68 84 72 65 44 44 65 - - - - - - - - - - - - - - - - - - - - Volatilisation Mean ng/m2/d -480 -430 -520 -740 -550 -53 -49 -78 -91 -68 -1.1 -1 -4.1 -3.2 -2.3 -1.1 -1.1 -4.2 -3.4 -2.4 -0.00025 -0.00024 -0.00099 -0.00075 -0.00056 -2.2 -2.2 -8.2 -6.5 -4.8 - - - - - - - - - - - - - - - - - - - - COV % 110 110 110 110 110 88 0 0 oo 0 0 oo o O OO 88 170 170 170 170 170 120 120 120 120 120 240 240 240 240 240 100 100 100 100 100 - - - - - - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d 520 140 210 -160 180 67 3.4 44 7.8 31 9.9 10 -0.43 2.3 5.5 1.5 2.4 -2.8 -1.4 -0.08 2.2 1.2 0.93 1.3 1.4 14 14 -2.3 2.2 6.8 - - - - - - - - - - - - - - - - - - - - COV % 130 410 300 540 380 210 1900 220 2000 350 110 95 1500 240 130 120 120 160 260 1100 100 69 68 68 84 82 74 350 310 110 - - - - - - - - - - - - - - - - - - - - IADN Results to 1996 Page 59 ------- Table C8: Atmospheric Fluxes to Lake Erie for 1996 (a) Banned Organochlorine Pesticides Species Season a-HCH W Sp Su F Annual dieldrin W Sp Su F Annual cis- W chlordane Sp Su F Annual trans- W chlordane Sp Su F Annual trans- W nonachlor Sp Su F Annual p,p'-DDD W Sp Su F Annual p,p'-DDE W Sp Su F Annual p,p'-DDT W Sp Su F Annual Lake Erie 1996 Wet Deposition Mean ng/m2/d 1 0.9 0.4 0.38 0.67 1.2 2 0.67 0.12 1 0.39 0.18 0.022 0.057 0.16 2 2.1 1.2 0.033 1.4 0.016 0.1 0.02 0.0063 0.036 0.78 0.041 0.0028 0.011 0.21 0.18 0.76 0.13 0.032 0.28 0.26 1.3 0.5 0.063 0.52 cov % 190 100 140 120 130 500 75 77 350 120 180 63 63 61 130 830 110 24 69 120 260 45 86 57 93 840 430 100 140 330 140 94 20 30 160 11 110 120 110 150 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 25 21 16 12 19 0.74 3.7 2.3 2 2 2 0.63 0.92 0.57 0.7 0.7 0.4 0.74 0.33 0.44 0.48 0.15 0.32 0.11 0.12 0.17 1.4 0.033 0.19 0.59 0.55 0.61 2.4 1.1 1.2 1.3 0.58 1.5 5.5 0.84 2.1 COV % 72 63 70 67 74 140 160 63 87 120 97 100 62 85 92 130 130 66 95 100 120 120 69 90 85 120 58 150 140 160 110 120 74 85 110 170 100 84 110 160 Volatilisation Mean ng/m2/d -7.8 -7.6 -21 -20 -14 -11 -9.7 -16 -20 -14 -0.55 -0.45 -0.54 -0.8 -0.59 -0.53 -0.4 -0.42 -0.65 -0.5 -0.57 -0.37 -0.28 -0.47 -0.42 - - - - - - - - - - - - - - - COV % 60 60 60 60 60 59 59 59 59 59 56 56 56 56 56 54 54 54 54 54 52 52 52 52 52 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d 17 14 -4.3 -7.8 4.7 -10 -6 -13 -18 -12 0.074 0.47 0.026 -0.098 0.12 -0.13 0.33 -0.089 -0.21 -0.024 -0.42 -0.045 -0.17 -0.35 -0.25 - - - - - - - - - - - - - - - COV % 86 89 410 210 280 93 160 100 97 110 940 200 1700 760 310 510 270 360 270 900 110 940 120 100 99 - - - - - - - - - - - - - - - IADN Results to 1996 Page 60 ------- (b) Current-use Pesticides Species Season g-HCH W (lindane) Sp Su F Annual a- W endosulphan Sp Su F Annual b- W endosulphan Sp Su F Annual endosulphan W sulphate Sp Su F Annual Lake Erie 1996 Wet Deposition Mean ng/ni2/d 0.4 0.28 0.025 0.0078 0.18 0.25 1.3 0.3 0.45 0.57 0.16 2.1 0.1 0.017 0.59 0.37 0.062 0.17 0.023 0.16 COV % 350 54 130 350 140 440 100 110 150 180 440 130 210 430 300 620 90 120 300 170 Dry Deposition Mean ng/ni2/d - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/ni2/d 2 2 7.1 17 3.4 7.4 0.62 7.6 56 7.4 18 0.18 0.71 3.8 1.1 1.4 - - - - - COV % 69 95 110 71 160 120 170 66 120 150 120 130 84 130 150 - - - - - Volatilisation Mean ng/ni2/d -1.4 -1.4 -3.6 -3.4 -2.4 -0.033 -0.029 -0.035 -0.04 -0.034 -0.00056 -0.00057 -0.0023 -0.0018 -0.0013 - - - - - COV % 110 110 110 110 110 100 100 100 100 100 99 99 99 99 99 - - - - - Net Gas Exchange Mean ng/ni2/d 0.8 5.8 13 0.027 5 0.58 7.6 56 7.4 18 0.18 0.71 3.8 1.1 1.4 - - - - - COV % 220 110 130 14000 220 120 170 66 120 150 110 130 84 130 150 - - - - - (c) Banned Organochlorine Commercial Chemicals Species Season HCB W Sp Su F Annual PCB18 W Sp Su F Annual PCB44 W Sp Su F Annual PCB52 W Sp Su F Annual PCB101 W Sp Su F Annual Sum-PCB W Sp Su F Annual Lake Erie 1996 Wet Deposition Mean ng/m2/d 0.033 0.086 0.017 0.0085 0.036 0.044 0.092 0.036 0.012 0.046 0.022 0.072 0.025 0.017 0.034 0.084 0.12 0.053 0.024 0.069 0.055 0.079 0.062 0.02 0.054 1.4 2.8 2.8 0.71 1.9 COV % 270 120 84 84 150 230 140 93 120 130 32 190 90 180 190 400 180 85 150 150 350 210 140 130 140 300 130 110 190 140 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 4.3 2.7 0.77 1.1 2 2 0.28 0.26 0.057 0.18 0.19 0.64 0.37 0.084 0.61 0.43 0.57 0.46 0.11 0.46 0.4 0.3 0.48 0.087 0.23 0.27 7.3 0.35 0.081 5.7 3.3 COV % 60 63 60 61 64 79 75 75 70 86 190 75 75 110 110 81 75 75 88 100 86 75 75 110 110 80 75 75 80 94 Volatilisation Mean ng/m2/d -4.1 -2.5 -1.7 -3 -2.8 -4.1 -2.6 -1.8 -3.1 -2.9 -2.8 -1.9 -1.5 -2.4 -2.1 -2.3 -1.6 -1.3 -2.1 -1.8 -1.2 -0.83 -0.73 -1.2 -0.98 -48 -31 -24 -40 -36 COV % 280 280 280 280 280 65 65 65 65 65 59 59 59 59 59 85 85 85 85 85 96 96 96 96 96 82 82 82 82 82 Net Gas Exchange Mean ng/m2/d 0.19 0.21 -0.96 -1.9 -0.61 -3.8 -2.3 -1.8 -3 -2.7 -2.2 -1.5 -1.4 -1.8 -1.7 -1.7 -1.1 -1.2 -1.7 -1.4 -0.87 -0.35 -0.64 -0.96 -0.71 -41 -31 -24 -34 -33 COV % 2600 1600 240 210 390 96 100 97 99 100 120 110 93 120 110 130 140 110 130 160 130 240 120 130 160 110 100 100 120 120 IADN Results to 1996 Page 61 ------- (d) Currently-Emitted PAHs and Metals Species Season PHEN W Sp Su F Annual PYR W Sp Su F Annual B(b+k)F W Sp Su F Annual B(a)P W Sp Su F Annual I(l,2,3-cd)P W Sp Su F Annual sum-PAH W (UN ECE) Sp Su F Annual Pb W Sp Su F Annual As W Sp Su F Annual Se W Sp Su F Annual Cd W Sp Su F Annual Lake Erie 1996 Wet Deposition Mean ng/m2/d 25 11 3.1 0.45 9.7 16 6.9 1.5 0.35 6.2 27 30 7.4 1.8 17 8.2 11 2.3 0.38 5.3 11 16 3.7 0.65 8 47 57 13 2.9 30 - - - - - - - - - - - - - - - - - - - - cov % 15 58 110 230 210 28 55 73 210 210 130 43 30 360 120 210 63 51 400 110 320 71 50 420 120 120 34 25 260 76 - - - - - - - - - - - - - - - - - - - - Dry Deposition Mean ng/m2/d 39 29 7.1 6.7 20 48 44 11 8.9 28 66 70 22 24 46 13 25 6.3 5.8 13 29 51 11 12 26 110 150 39 42 84 - - - - - - - - - - - - - - - - - - - - COV % 100 150 100 100 140 100 150 110 100 140 91 110 79 84 110 100 160 110 100 150 110 150 110 110 150 100 120 100 100 110 - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 780 400 350 270 450 93 40 44 51 57 4.5 3.7 2.6 4 3.7 1.8 1.3 0.93 1.4 1.4 1.1 0.84 0.61 0.93 0.88 7.5 5.9 4.1 6.4 6 - - - - - - - - - - - - - - - - - - - - COV % 89 78 65 92 84 100 100 65 97 100 70 58 61 66 66 69 58 64 71 67 69 58 70 70 69 46 40 42 45 45 - - - - - - - - - - - - - - - - - - - - Volatilisation Mean ng/m2/d -480 -410 -530 -710 -530 -51 -46 -77 -87 -65 -0.92 -0.94 -3.7 -3 -2.1 -1 -1 -3.8 -3.2 -2.2 -0.00022 -0.00022 -0.00089 -0.00071 -0.00051 -1.9 -2 -7.5 -6.2 -4.4 - - - - - - - - - - - - - - - - - - - - COV % 110 110 110 110 110 88 0 0 oo 0 0 oo o O OO 88 170 170 170 170 170 120 120 120 120 120 240 240 240 240 240 100 100 100 100 100 - - - - - - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d 300 -12 -180 -440 -82 42 -6.2 -33 -37 -8.6 3.6 2.8 -1.1 1 1.6 0.85 0.33 -2.9 -1.7 -0.85 1.1 0.84 0.61 0.93 0.88 5.6 3.9 -3.3 0.22 1.6 - - - - - - - - - - - - - - - - - - - - COV % 250 3800 310 170 1100 220 880 230 250 18000 89 84 550 500 180 160 340 140 200 390 69 58 70 70 69 64 67 220 2800 180 - - - - - - - - - - - - - - - - - - - - IADN Results to 1996 Page 62 ------- Table C9: Atmospheric Fluxes to Lake Ontario for 1995 (a) Banned Organochlorine Pesticides Species Season a-HCH W Sp Su F Annual dieldrin W Sp Su F Annual cis- W chlordane Sp Su F Annual trans- W chlordane Sp Su F Annual trans- W nonachlor Sp Su F Annual p,p'-DDD W Sp Su F Annual p,p'-DDE W Sp Su F Annual p,p'-DDT W Sp Su F Annual Lake Ontario 1995 Wet Deposition Mean ng/m2/d 3.3 1.9 0.96 6.1 3.1 0.3 0.98 0.35 0.64 0.57 0.055 0.038 0.017 0.021 0.033 0.025 0.089 0.017 0.033 0.041 0.045 0.016 0.03 0.012 0.026 0.045 0.11 0.041 0.045 0.06 0.45 2.1 0.27 0.23 0.77 4.9 2.4 0.47 0.14 2 cov % 30 60 29 47 55 120 31 25 59 93 150 47 76 81 160 110 56 35 76 140 56 450 72 230 330 65 35 50 92 140 180 52 42 160 160 87 87 84 57 250 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 19 13 12 19 16 1.8 3.2 3.1 3.7 2.9 0.7 0.77 0.48 0.98 0.73 0.7 0.65 0.29 0.81 0.61 0.38 0.41 0.15 0.38 0.33 0.083 0.043 0.13 0.16 0.1 2.1 2 2 1.4 3.2 2.2 0.77 0.61 1.1 1.1 0.9 COV % 69 60 62 65 64 110 98 93 91 120 110 84 93 97 110 120 87 97 95 110 110 82 94 95 110 110 98 81 110 110 140 87 110 98 120 150 88 110 100 130 Volatilisation Mean ng/m2/d -11 -8.3 -23 -23 -16 -30 -21 -37 -58 -37 -1.1 -0.81 -1 _9 -1.2 -1.4 -0.95 -1 -2.2 -1.4 -1.5 -1 -0.7 -1.9 -1.3 - - - - - - - - - - - - - - - COV % 56 56 56 56 56 57 57 57 57 57 50 50 50 50 50 51 51 51 51 51 54 54 54 54 54 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d 7.5 4.9 -11 -4.7 -0.83 -28 -18 -34 -54 -34 -0.44 -0.04 -0.55 -1 -0.51 -0.67 -0.31 -0.71 -1.4 -0.77 -1.1 -0.6 -0.55 -1.6 -0.96 - - - - - - - - - - - - - - - COV % 170 160 160 390 4400 91 100 93 92 95 66 1600 120 130 230 190 230 96 110 130 110 130 100 99 110 - - - - - - - - - - - - - - - IADN Results to 1996 Page 63 ------- (b) Current-use Pesticides Species Season g-HCH W (lindane) Sp Su F Annual a- W endosulphan Sp Su F Annual b- W endosulphan Sp Su F Annual endosulphan W sulphate Sp Su F Annual Lake Ontario 1995 Wet Deposition Mean ng/ni2/d 1.4 4.3 1.4 0.64 1.9 0.33 7 2.2 0.86 2.6 0.5 6.6 5.6 0.62 3.3 - - - - - COV % 48 64 15 59 110 77 83 61 53 140 42 75 120 74 140 - - - - - Dry Deposition Mean ng/ni2/d - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/ni2/d 2.7 6.4 5.7 4.4 4.8 2.7 39 40 6.6 22 0.68 4.9 12 2.5 5 - - - - - COV % 74 89 70 70 90 95 230 120 110 220 190 220 150 120 230 - - - - - Volatilisation Mean ng/ni2/d -2.2 -1.7 -4.2 -4.3 -3.1 -0.0095 -0.0075 -0.0086 -0.011 -0.0092 -0.00054 -0.0004 -0.0015 -0.0013 -0.00093 - - - - - COV % 64 64 64 64 64 82 82 82 82 82 110 110 110 110 110 - - - - - Net Gas Exchange Mean ng/ni2/d 0.47 4.7 1.5 0.19 1.7 2.7 38 40 6.6 22 0.68 4.9 12 2.5 5 - - - - - COV % 520 110 290 2100 210 81 230 120 110 220 180 220 150 120 230 - - - - - (c) Banned Organochlorine Commercial Chemicals Species Season HCB W Sp Su F Annual PCB18 W Sp Su F Annual PCB44 W Sp Su F Annual PCB52 W Sp Su F Annual PCB101 W Sp Su F Annual Sum-PCB W Sp Su F Annual Lake Ontario 1995 Wet Deposition Mean ng/m2/d 0.2 0.075 0.078 0.066 0.11 0.23 0.095 0.056 0.087 0.12 0.41 0.36 0.13 0.24 0.28 0.65 0.36 0.18 0.27 0.37 0.46 0.27 0.15 0.16 0.26 8.9 6.5 2.3 4.5 5.6 COV % 100 64 57 82 160 93 200 63 82 180 140 57 28 130 120 130 200 14 110 210 140 140 42 110 170 110 78 31 88 150 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 6 4.1 0.33 2.4 3.2 1.5 1.1 0.31 1.1 0.99 0.42 0.45 0.14 0.35 0.34 0.69 0.82 0.33 0.77 0.65 0.34 0.36 0.12 0.31 0.28 10 12 3.6 11 9.1 COV % 59 61 66 65 69 68 64 67 64 67 81 63 73 81 81 81 65 72 82 83 98 65 79 88 91 71 61 70 79 76 Volatilisation Mean ng/m2/d -10 -6.5 -3.9 -11 -7.9 -4.5 -3 -1.9 -5.2 -3.6 -3.8 -2.6 -1.9 -4.8 -3.3 -2.5 -1.7 -1.3 -3.3 -2.2 -1.3 -0.87 -0.74 -1.8 -1.2 -51 -34 -24 -63 -43 COV % 96 96 96 96 96 51 51 51 51 51 50 50 50 50 50 55 55 55 55 55 53 53 53 53 53 51 51 51 51 51 Net Gas Exchange Mean ng/m2/d -4 -2.4 -3.6 -8.7 -4.7 -3 -1.9 -1.6 -4.1 -2.6 -3.4 -2.1 -1.7 -4.4 -2.9 -1.8 -0.87 -1 -2.5 -1.5 -0.93 -0.51 -0.62 -1.5 -0.89 -41 -23 -20 -52 -34 COV % 250 260 120 130 150 110 100 83 87 92 75 73 69 69 70 120 150 110 110 120 110 130 94 95 100 96 100 85 87 91 IADN Results to 1996 Page 64 ------- (d) Currently-Emitted PAHs and Metals Species Season PHEN W Sp Su F Annual PYR W Sp Su F Annual B(b+k)F W Sp Su F Annual B(a)P W Sp Su F Annual I(l,2,3-cd)P W Sp Su F Annual sum-PAH W (UN ECE) Sp Su F Annual Pb W Sp Su F Annual As W Sp Su F Annual Se W Sp Su F Annual Cd W Sp Su F Annual Lake Ontario 1995 Wet Deposition Mean ng/m2/d 20 12 11 22 16 28 13 11 21 18 38 19 14 29 25 10 8.2 6.8 11 9.1 15 8 8 11 10 64 35 29 51 45 1400 800 780 1400 1100 150 120 73 210 140 190 150 96 300 190 110 47 79 66 76 cov % 75 92 29 450 160 66 100 45 340 160 38 91 22 240 120 58 99 44 400 160 57 120 34 450 190 30 60 20 190 89 410 76 700 140 600 240 110 910 150 400 190 160 570 160 590 170 70 690 88 660 Dry Deposition Mean ng/m2/d 7 3.7 1.9 3.4 4 13 6.4 2.8 4.6 6.7 31 13 6.6 9 15 6.2 4.3 2.9 3.6 4.2 17 11 5.1 7.7 10 55 28 15 20 30 630 630 360 260 470 34 34 22 31 30 27 5.2 32 23 22 14 10 3.6 - 7.1 COV % 120 140 100 120 140 150 180 140 120 160 140 110 100 85 140 140 160 140 110 140 140 140 120 110 140 120 110 110 100 120 140 120 130 110 130 160 120 150 120 170 240 170 190 190 220 180 150 180 - 200 Gas Exchange Gas Absorption Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Volatilisation Mean ng/m2/d -240 -180 -240 -390 -260 -36 -27 -46 -59 -42 -0.74 -0.55 _9 -1.7 -1.3 -1.1 -0.83 -3 -2.6 -1.9 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % 81 81 81 81 81 86 86 86 86 86 98 98 98 98 98 59 59 59 59 59 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - IADN Results to 1996 Page 65 ------- Table CIO: Atmospheric Fluxes to Lake Ontario for 1996 (a) Banned Organochlorine Pesticides Species Season a-HCH W Sp Su F Annual dieldrin W Sp Su F Annual cis- W chlordane Sp Su F Annual trans- W chlordane Sp Su F Annual trans- W nonachlor Sp Su F Annual p,p'-DDD W Sp Su F Annual p,p'-DDE W Sp Su F Annual p,p'-DDT W Sp Su F Annual Lake Ontario 1996 Wet Deposition Mean ng/m2/d 5 5.2 9 5.7 4.5 0.34 0.83 0.34 1.1 0.65 0.046 0.085 0.033 0.091 0.063 0.057 0.07 0.026 0.07 0.056 0.098 0.55 0.089 0.36 0.27 0.096 0.11 0.035 0.1 0.086 0.34 0.46 0.17 0.18 0.29 0.45 0.98 0.28 0.63 0.59 cov % 27 25 47 42 55 260 26 39 91 74 230 31 31 100 64 120 97 120 32 72 270 110 93 130 160 210 22 17 70 53 43 58 44 14 67 150 100 85 53 91 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 17 12 11 11 13 1.4 2.7 2.9 2 2.3 0.41 0.82 0.71 0.66 0.65 0.41 0.71 0.43 0.4 0.49 0.24 0.38 0.19 0.17 0.25 0.04 0.17 0.17 0.097 0.12 1.1 2.3 2 2 1.1 1.7 0.3 1.2 2.6 0.99 1.3 COV % 61 61 59 60 62 88 100 70 91 99 79 100 69 77 97 87 110 70 76 96 83 110 71 84 100 60 74 71 78 93 86 110 80 78 120 94 130 77 79 130 Volatilisation Mean ng/m2/d -10 -7.9 -19 -20 -14 -27 -21 -36 -48 -33 -1.1 -0.8 -1 -1.6 -1.1 -1.3 -0.95 -1 -1.7 -1.3 -1.5 -1.1 -0.76 -1.5 -1.2 - - - - - - - - - - - - - - - COV % 56 56 56 56 56 57 57 57 57 57 50 50 50 50 50 51 51 51 51 51 54 54 54 54 54 - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d 6.6 4.4 -8.4 -8.7 -1.5 -26 -18 -33 -46 -31 -0.67 0.022 -0.33 -0.95 -0.48 -0.89 -0.25 -0.62 -1.3 -0.77 -1.3 -0.69 -0.57 -1.3 -0.96 - - - - - - - - - - - - - - - COV % 160 170 170 180 620 90 98 93 90 94 66 3600 180 98 260 110 350 110 87 130 98 130 100 91 110 - - - - - - - - - - - - - - - IADN Results to 1996 Page 66 ------- (b) Current-use Pesticides Species Season g-HCH W (lindane) Sp Su F Annual a- W endosulphan Sp Su F Annual b- W endosulphan Sp Su F Annual endosulphan W sulphate Sp Su F Annual Lake Ontario 1996 Wet Deposition Mean ng/ni2/d 1.9 6.7 2.3 4 3.7 0.55 1.7 5.9 0.85 2.3 0.64 2.2 1.6 1.1 1.4 - - - - - COV % 21 41 95 30 63 230 45 180 49 220 49 66 250 55 150 - - - - - Dry Deposition Mean ng/ni2/d - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/ni2/d 2.3 4.7 11 2.6 5.2 1.7 11 51 6.1 18 0.077 1.9 9.2 1 3 - - - - - COV % 63 97 100 69 150 64 170 85 180 170 88 130 82 170 160 - - - - - Volatilisation Mean ng/ni2/d -2.1 -1.6 -3.5 -3.7 -2.7 -0.0095 -0.0077 -0.0084 -0.0099 -0.0089 -0.00049 -0.00037 -0.0012 -0.0011 -0.00079 - - - - - COV % 64 64 64 64 64 82 82 82 82 82 110 110 110 110 110 - - - - - Net Gas Exchange Mean ng/ni2/d 0.27 3.1 7.5 -1.1 2.5 1.6 11 51 6.1 17 0.076 1.9 9.2 1 3 - - - - - COV % 750 140 150 290 270 40 170 85 180 170 73 130 82 170 160 - - - - - (c) Banned Organochlorine Commercial Chemicals Species Season HCB W Sp Su F Annual PCB18 W Sp Su F Annual PCB44 W Sp Su F Annual PCB52 W Sp Su F Annual PCB101 W Sp Su F Annual Sum-PCB W Sp Su F Annual Lake Ontario 1996 Wet Deposition Mean ng/m2/d 0.16 0.12 0.16 0.066 0.13 0.12 0.082 0.13 0.077 0.1 0.27 0.21 0.15 0.16 0.2 0.51 0.32 0.31 0.29 0.36 0.26 0.21 0.12 0.19 0.19 5.1 3.7 3 3.3 3.8 COV % 210 300 89 24 130 180 300 80 56 110 190 280 56 44 130 200 300 62 41 110 230 270 41 33 130 230 270 52 29 120 Dry Deposition Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gas Exchange Gas Absorption Mean ng/m2/d 6.9 4.8 0.59 1.5 3.4 1.9 1.2 0.45 0.72 1.1 0.34 0.36 0.21 0.24 0.29 0.69 0.94 0.51 0.58 0.68 0.25 0.46 0.23 0.27 0.3 9.9 7.6 4.2 5.5 6.8 COV % 59 61 67 64 67 61 79 69 110 83 74 84 71 97 91 74 81 69 86 88 75 93 69 72 91 69 82 71 110 90 Volatilisation Mean ng/m2/d -10 -7.1 -4.3 -8.3 -7.5 -4.6 -3.2 -2.1 -3.9 -3.4 -3.8 -2.7 _9 -3.7 -3 -2.4 -1.8 -1.4 -2.5 _9 -1.2 -0.89 -0.79 -1.4 -1.1 -51 -36 -26 -48 -40 COV % 96 96 96 96 96 51 51 51 51 51 50 50 50 50 50 55 55 55 55 55 53 53 53 53 53 51 51 51 51 51 Net Gas Exchange Mean ng/m2/d -3.4 -2.3 -3.7 -6.8 -4.1 -2.7 -2 -1.6 -3.2 -2.4 -3.5 -2.4 -1.8 -3.4 -2.8 -1.8 -0.82 -0.93 _9 -1.4 -0.98 -0.43 -0.56 -1.1 -0.78 -41 -29 -22 -43 -34 COV % 300 310 120 130 150 130 110 88 87 94 73 72 70 69 70 120 170 120 110 130 100 170 110 96 120 95 90 86 83 87 IADN Results to 1996 Page 67 ------- (d) Currently-Emitted PAHs and Metals Species Season PHEN W Sp Su F Annual PYR W Sp Su F Annual B(b+k)F W Sp Su F Annual B(a)P W Sp Su F Annual I(l,2,3-cd)P W Sp Su F Annual sum-PAH W (UN ECE) Sp Su F Annual Pb W Sp Su F Annual As W Sp Su F Annual Se W Sp Su F Annual Cd W Sp Su F Annual Lake Ontario 1996 Wet Deposition Mean ng/m2/d 39 64 7.8 35 37 28 75 7.8 40 38 42 79 11 46 44 18 27 2.7 14 15 26 51 3.2 15 24 85 160 16 76 84 1000 680 700 460 720 110 82 59 84 84 360 82 82 120 160 62 51 49 63 56 cov % 130 110 77 170 140 210 140 160 89 170 160 210 28 64 200 180 240 100 36 230 200 150 110 48 260 110 120 34 42 150 810 310 190 68 210 430 250 41 39 150 710 200 75 51 84 390 190 72 25 110 Dry Deposition Mean ng/m2/d 19 5.1 3.5 8.5 9.1 26 4.8 4.4 13 12 56 10 12 63 36 14 3.4 3.8 13 8.6 29 6.7 4.6 37 19 99 21 20 110 63 790 500 800 880 740 150 46 82 77 88 32 14 79 74 50 14 8.6 10 26 15 COV % 120 170 130 130 150 120 150 130 140 150 100 110 130 170 170 110 140 140 170 160 110 120 210 160 170 110 110 130 140 140 120 110 110 120 120 120 140 110 130 130 270 180 110 140 150 140 130 130 150 150 Gas Exchange Gas Absorption Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Volatilisation Mean ng/m2/d -230 -180 -240 -320 -240 -34 -27 -43 -51 -39 -0.67 -0.51 -1.6 -1.5 -1.1 -1 -0.78 -2.4 -2.3 -1.6 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % 81 81 81 81 81 86 86 86 86 86 98 98 98 98 98 59 59 59 59 59 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Net Gas Exchange Mean ng/m2/d - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - COV % - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - IADN Results to 1996 Page 68 ------- Appendix D: Relative Loadings of IADN Substances IADN Results to 1996 Page 69 ------- IADN Results to 1996 Page 70 ------- Figure Dl: Loadings as a Proportion of Total Deposition to Lake Superior in 1995. Lake Superior 1995 100 50 -50 -100 - -150 -- -200 - - -250 - - -300 D Volatilisation D Gas Absorption D Wet Deposition D Dry Deposition N.B. Positive values denote deposition from atmosphere to lake. Negative values denote volatilisation from lake to atmosphere. IADN Results to 1996 Page 71 ------- Figure D2: Loadings as a Proportion of Total Deposition to Lake Superior in 1996. Lake Superior 1996 -400 D Volatilisation Q Gas Absorption D Wet Deposition D Dry Deposition N.B. Positive values denote deposition from atmosphere to lake. Negative values denote volatilisation from lake to atmosphere. IADN Results to 1996 Page 72 ------- Figure D3: Loadings as a Proportion of Total Deposition to Lake Michigan in 1995. Lake Michigan 1995 -400 D Volatilisation Q Gas Absorption D Wet Deposition D Dry Deposition N.B. Positive values denote deposition from atmosphere to lake. Negative values denote volatilisation from lake to atmosphere. * indicates substances for which no volatilisation estimate could be made due to lack of water concentration data IADN Results to 1996 Page 73 ------- Figure D4: Loadings as a Proportion of Total Deposition to Lake Michigan in 1996. Lake Michigan 1996 100 50 0 -50 - -100 - -150 - -200 - - -250 - - |l M I I M, Ml I ir~i| ^M 1 1 1 -350 0 3 -519%- -484% ] Volatilisation Q Gas Absorption D Wet Deposition Q Dry Deposition N.B. Positive values denote deposition from atmosphere to lake. Negative values denote volatilisation from lake to atmosphere. * indicates substances for which no volatilisation estimate could be made due to lack of water concentration data IADN Results to 1996 Page 74 ------- Figure D5: Loadings as a Proportion of Total Deposition to Lake Huron in 1995. Lake Huron 1995 -50 -100 - -150 - -200 1 1 11 + 'I' + 'I1 + 'I H 1 1 1 1 1 1 1 1 o 3 Q w Q Q Q Q "i, la a i a 1 D Volatilisation Q Gas Absorption D Wet Deposition Q Dry Deposition N.B. Positive values denote deposition from atmosphere to lake. Negative values denote volatilisation from lake to atmosphere. * indicates substances for which no volatilisation estimate could be made due to lack of water concentration data IADN Results to 1996 Page 75 ------- Figure D6: Loadings as a Proportion of Total Deposition to Lake Huron in 1996. Lake Huron 1996 100 50 - -50 - -100 -- -150 - -200 -I 1' Ml M -I 1- 0 3 ] Volatilisation D Gas Absorption D Wet Deposition D Dry Deposition N.B. Positive values denote deposition from atmosphere to lake. Negative values denote volatilisation from lake to atmosphere. * indicates substances for which no volatilisation estimate could be made due to lack of water concentration data IADN Results to 1996 Page 76 ------- Figure D7: Loadings as a Proportion of Total Deposition to Lake Erie in 1995. Lake Erie 1995 50 -50 -100 - -150 - -200 - - -250 -300 * * * 0 3 -464% ] Volatilisation D Gas Absorption D Wet Deposition D Dry Deposition N.B. Positive values denote deposition from atmosphere to lake. Negative values denote volatilisation from lake to atmosphere. * indicates substances for which no volatilisation estimate could be made due to lack of water concentration data IADN Results to 1996 Page 77 ------- Figure D8: Loadings as a Proportion of Total Deposition to Lake Erie in 1996. Lake Erie 1996 D Volatilisation Q Gas Absorption D Wet Deposition D Dry Deposition N.B. Positive values denote deposition from atmosphere to lake. Negative values denote volatilisation from lake to atmosphere. * indicates substances for which no volatilisation estimate could be made due to lack of water concentration data IADN Results to 1996 Page 78 ------- Figure D9: Loadings as a Proportion of Total Deposition to Lake Ontario in 1995. -400 Lake Ontario 1995 ] Volatilisation Q Gas Absorption D Wet Deposition Q Dry Deposition N.B. Positive values denote deposition from atmosphere to lake. Negative values denote volatilisation from lake to atmosphere. * indicates substances for which no volatilisation estimate could be made due to lack of water concentration data IADN Results to 1996 Page 79 ------- Figure DIG: Loadings as a Proportion of Total Deposition to Lake Ontario in 1996. Lake Ontario 1996 100 50 0 -50 -100 -- -150 - -200 - - -250 -300 - - -350 - -400 -1122% R -618%- R ffl D Volatilisation D Gas Absorption D Wet Deposition D Dry Deposition N.B. Positive values denote deposition from atmosphere to lake. Negative values denote volatilisation from lake to atmosphere. * indicates substances for which no volatilisation estimates could be made due to lack of water concentration data IADN Results to 1996 Page 80 ------- Appendix E: Variation in Precipitation and Air Concentration within Lake Basins for 1996 IADN Results to 1996 Page 81 ------- IADN Results to 1996 Page 82 ------- Table El: 1996 Annual Volume-Weighted Mean Pesticide Concentrations in Precipitation (ng/L) Lake Superior Michigan rluron irie Ontario Station Eagle Harbor Brule River Wolf Ridge Siblev Turkey Lakes Mean Master-Mean Sleeoine Bear Dun IIT (Chicago) Mean Master-Mean Burnt Island Grand Bend Grand Bend Mean Master-Mean Sturgeon Point Pelee Island Port Stanley Rock Point Mean Master-Mean Point Petre Point Petre Burlington Metro Zoo (Toront Mean Master-Mean Agency EPA/IU EPA/IU OME ECEHD ECEHD all all EPA/IU EPA/IU all all ECEHD ECEHD OME all all EPA/IU ECEHD OME ECEHD all all ECEHD ECNWRI ECEHD ECEHD all all 0-HCH 0.76 0.77 1.2 1.6 1 8 1.2 0.62 0.18 0.88 0.53 0.34 2.4 1.9 1.2 1.9 1.3 0.31 2.4 1.3 23 1.6 0.2 2.1 1.5 3.3 2.3 2.3 0.92 dieldrin 0.22 0.2 1.5 0.49 03 0.54 0.41 0.32 1.3 0.82 0.39 0.92 0.92 0.083 0.64 1.4 0.31 1.2 1.2 052 0.82 0.38 0.56 0.22 0.78 0.59 0.54 1 os-chlordane 0.024 0.043 0.018 0.073 0081 0.048 0.5 0.047 0.14 0.095 0.49 0.081 0.083 0.02 0.06; 1.3 0.054 0.092 0.026 006 0.0 58 0.93 0.69 0.022 0.059 0.067 0.21 3.3 ra»s-chlordan 0.11 0.034 0.018 0.066 0044 0.054 2 0.15 0.55 0.35 0.43 0.086 0.068 0.02 0.058 1.5 0.33 0.076 0.026 0057 0.12 2.7 0.073 0.019 0.051 0.061 0.051 1.4 p,p' -ODD 0.0068 0.0052 0.018 0.076 0089 0.039 0.17 0.024 0.11 0.065 0.37 0.13 0.13 0.02 0.092 1.4 0.0091 0.21 0.13 008 0.11 0.084 0.085 0.029 0.14 0.2 0.11 0.76 p,p' -DDE 0.016 0.024 0.1 0.19 0 12 0.091 0.18 0.052 0.4 0.23 0.23 0.13 0.28 0.032 0.15 0.88 0.097 2.2 0.85 036 0.87 0.11 0.37 0.1 0.69 4.5 1.4 0.26 p,p' -DDT 0.041 0.02 0.018 0.13 0087 0.059 0.69 0.14 1 0.59 0.24 0.18 0.77 0.12 0.36 0.51 0.2 2.7 0.026 0 18 0.77 0.26 0.23 0.21 1.7 1.1 0.83 0.28 THCH 0.52 0.91 0.055 1.8 15 0.94 0.55 0.086 0.89 0.49 0.18 1.8 3.3 0.073 1.7 1.1 0.039 2.6 0.073 14 ; 0.038 1.3 1.5 2.7 2.4 2 0.66 tt-endosulphar 0.49 0.43 - 0.48 045 0.46 1.1 0.25 0.46 0.35 0.7 0.6 0.91 _ 0.75 0.79 0.33 0.91 _ 07 0.65 0.5; 1 1.6 2.4 1.2 ;.5 0.66 P-endosulphar 0.77 0.54 - 0.74 1 1 0.78 0.98 0.13 0.39 0.26 0.52 1.1 1.7 _ 1.4 0.77 0.19 1.6 _ 13 ; 0.18 2.1 0.72 4.4 2 2.3 0.91 IADN Results to 1996 Page 83 ------- Table E2: 1996 Annual Volume-Weighted Mean HCB, PCS and PAH Concentrations in Precipitation (ng/L) Lake Superior Michigan Huron Erie Ontario Station Eagle Harbor Brule River Wolf Ridge Sibley Turkey Lakes Mean Master-Mean Sleeping Bear Duns IIT (Chicago) Mean Master: Mean Burnt Island Grand Bend Grand Bend Mean Master-Mean Sturgeon Point Pelee Island Port Stanley Rock Point Mean Master-Mean Point Petre Point Petre Burlington Metro Zoo (Toront( Mean Master-Mean Agency EPA/IU EPA/IU OME ECEHD ECEHD all all EPA/IU EPA/IU all all ECEHD ECEHD OME all all EPA/IU ECEHD OME ECEHD all all ECEHD EC NWRI ECEHD ECEHD all all HCB 0.013 0.014 0.024 0.004 0.012 0.013 0.96 0.012 0.034 0.023 0.51 0.018 0.002 0.02 0.013 1.4 0.013 0.15 0.096 0.073 0.083 0.16 0.076 0.043 0.002 0.05 0.043 1.8 PCB18 0.033 0.028 - - - 0.031 1.1 0.019 0.079 0.049 0.4 - - - - - 0.018 _ - - 0.018 1 - 0.036 - - 0.036 - PCB44 0.016 0.0099 - - - 0.013 1.2 0.011 0.095 0.053 0.2 - - - - - 0.017 _ - - o.o;/ ; - 0.06 - - 0.06 - PCB52 0.018 0.032 - - - 0.025 0.72 0.023 0.13 0.075 0.31 - - - - - 0.028 _ - - 0.028 1 - 0.11 - - 0.11 - PCB101 0.021 0.018 - - - 0.019 1.1 0.015 0.13 0.074 0.2 - - - - - 0.023 _ - - 0.023 ; - 0.055 - - 0.055 - PHEN 1.4 1.4 10 14 7.2 6.8 0.21 1.6 87 44 0.036 6.1 7.2 8 7.1 0.86 2.5 15 18 9.7 ;; 0.22 7.8 11 16 14 12 0.64 PYR 1 0.81 2.5 3.3 8.4 3.2 0.32 1 99 50 0.02 7.2 10 3 6.7 1.1 1.5 12 8.4 7.1 7.4 0.21 5.7 11 19 13 12 0.47 B(k)F 0.63 0.63 3.6 4.7 4.1 2.7 0.23 0.84 38 19 0.043 5.4 5.1 4.1 4.9 1.1 1.6 8 5.9 4.8 5.1 0.32 5.6 3.7 12 5.8 6.7 0.84 B(a)P 0.51 0.49 0.71 6.7 5.1 2.7 0.19 0.79 60 30 0.026 8 5.6 0.82 4.8 1.7 1.5 7.7 2.3 5.3 4.2 0.36 6.2 4 9.5 7.4 6.8 0.92 IADN Results to 1996 Page 84 ------- Table E3: 1996 Annual Pesticide Concentrations in Air (pg/m3) Lake Basin Superior Michigan Huron H.rie Ontario Station Eaale Harbor Rmle River Mean Master:Mean Sleeoina Bear Dunes IIT (Chicaso"! Mean Master:Mean Burnt Island Stiiroeon Point Point Petre Asencv EPA/IU F.PA/TTI all all EPA/IU EPA/IU all all AES F.PA/TTI AES Medium XAD XAD XAD XAD PUF YAD PUF 0-HCH 78 86 82 0.95 64 99 82 0.79 30 67 32 dieldrin 9.8 7 9 8.5 1.2 15 140 78 0.2 7.7 IS 11 cifi -chlordane 3.4 3 1 3.3 1 5 3 45 25 0.21 2.1 8 4 runs -chlordan 2.4 9 2.2 1.1 4.5 47 26 0.18 1.8 6 8 3.4 P.p'-DDD 0.86 1 9 1 0.84 1.1 2 9 2 0.57 0.13 1 9 0.38 V,v' -DDE 1.6 1 1.3 1.2 6.7 36 21 0.31 1.9 15 11 P.p'-DDT 2.8 064 1.7 1.6 3 3 36 19 0.17 0.6 14 5 TFHCH 16 19 14 1.2 21 52 36 0.58 93 30 15 Gtendosulohan 24 15 20 1.2 65 83 74 0.88 10 77 58 P-endosulohan 1.7 1 4 7.5 1.1 6.8 6.7 6.8 1 1.2 6 12 Table E4: 1996 Annual HCB and PCB Concentrations in Air (pg/m3) T.nkp Rnsin Superior Michigan Huron Erie Ontario STATION Eagle Harbor Brule River Mean Master:Mean Sleeping Bear Dunes IIT (Chicago) Mean Master:Mean Burnt Island Sturgeon Point Point Petre A Qpnrv EPA/IU EPA/IU all all EPA/IU EPA/IU all all AES EPA/IU AES Medium XAD XAD _ - XAD XAD _ - PUF XAD PUF HCR 63 70 66 0.95 65 100 84 0.78 31 62 35 PCR18 2.8 3.4 3.1 0.91 5.5 61 33 0.16 6.6 6.1 11 PCR44 2.3 3 2.6 0.86 5 110 59 0.085 1.1 8.5 2.7 PCRS2 3.2 3.9 3.5 0.89 5.3 80 43 0.12 1 10 5.4 prRim 2.3 2.1 2.2 1 3.1 52 27 0.11 0.92 5.5 2.7 IADN Results to 1996 Page 85 ------- Table E5: 1996 Annual PAH Concentrations in Air (pg/m3) Lake Rnsin Superior Michigan Huron Erie Ontario STATION Eagle Harbor Brule River Mean Master.Mean Sleeping Bear Dunes IIT (Chicago) Mean Master.Mean Burnt Island Sturgeon Point PtPetre A Qpnrv EPA/IU EPA/IU all all EPA/IU EPA/IU all all AES EPA/IU AES Medium GEE GEE _ - GEE GEE _ - GEE GEE GEE PHFN 18 84 51 0.35 23 1000 520 0.045 26 100 52 PVR 18 68 43 0.42 24 2000 7000 0.02J 32 140 72 RfkW 9.4 24 17 0.56 12 620 J20 0.038 19 76 58 Rfa'lP 8.2 18 13 0.63 11 780 400 0.027 26 65 57 IADN Results to 1996 Page 86 ------- Appendix F: Annual Mass Fluxes to the Great Lakes from 1992 to 1996 IADN Results to 1996 Page 87 ------- IADN Results to 1996 Page 8 8 ------- Figure Fl: Annual Average Wet Deposition Flux (ng/m2/d) of Organochlorine Pesticides Lake Superior Lake Michigan S 6 a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT D1»2 g 1993 D1994 D 1995 g 1996 I a a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT IB 1992 B1993 Q1994 Q1995 g1996 I 16 I 5 f-^ rfl a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT |B1992 B 1993 n 1994 g 1995 J19 a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT I E n n. a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT IADN Results to 1996 Page 89 ------- Figure F2: Annual Average Dry Deposition Flux (ng/m2/d) of Organochlorine Pesticides Lake Superior n a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT J1992 H1993 Q 1994 Q 1995 11996 Lake Michigan e SI 1 o ! a rli ,rTHl , , n , n .PI rn a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT 1^1992 H1 1993 Q 1994 Q 1995 H19 Data not available for Lake Huron s S I.Jlh n.. n.ll n a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT |g1992 J1993 Q1994 Q1995 Data not available for Lake Ontario IADN Results to 1996 Page 90 ------- Figure F3: Annual Average Net Gas Exchange Flux (ng/m2/d) of Organochlorine Pesticides (Positive values denote net gas absorption, negative values denote net volatilisation) Lake Superior Lake Michigan a -1= tj a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT 1992 H1993 Q 1994 D 1995 Q 1996 I e si E 5 E -5 & -<5 n a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT 1^1992 B1993 Q 1994 Q 1995 g1996 I j a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT |B 1992 H1993 Q 1994 n 1995 1996 | 5 -15 i -25 .n n a-HCH g-HCH dieldrin p,p'-DDD p,p'-DDE p,p'-DDT £ 5 £ -1 ,-rm . . ._ r. IIK^ if -48 a-HCH g-HCH dield -U n p,p'-DDD p,p'-DDE p,p'-DDT JQ1992 Q1993Q1994Q1995 >1996 | IADN Results to 1996 Page 91 ------- Figure F4: Annual Average Wet Deposition Flux (ng/m2/d) of PCBs Lake Superior Lake Michigan i-l l-m r-rTTTI. rrr-Th PCB52 PCB101 Sum- PCB'0.1 31992 1993D1994D1995 H19! 1 3 0.! r-*Tb.ra "L .n-lTh.nJTb PCB52 PCB101 1992 1993 01994 D1995 D1996 I PCB101 Sum- PCB'0.1 ID1992 D1993 O1994 Q1995 Lake Erie Lake Ontario I1 I O.i rffh,. HT n.i-rTfL PCB101 Sum- PCB'0.1 31992 D1993 a1994 Q1995 Q19 IADN Results to 1996 Page 92 ------- Figure F5: Annual Average Dry Deposition Flux (ng/m2/d) of PCBs I Lake Superior PCB101 Sum- PCB'0.1 1992 B1993 O1994 D1995 Bigg6 I Lake Michigan 31992 01993 O1994 O1995 19961 Data not available for Lake Huron I Lake Erie [1992 1993 D1994 O1995 O19 Data not available for Lake Ontario IADN Results to 1996 Page 93 ------- Figure F6: Annual Average Net Gas Exchange Flux (ng/m2/d) of PCBs (Positive values denote net gas absorption, negative values denote net volatilisation) Lake Superior Lake Michigan -oo PCB18 PCB44 PCB52 PCB101 SumPCB'0.1 PCB18 PCB44 PCB52 PCB101 SumPCB'0.1 If 1992 g 1993 Q 1994 []1995 g1996 \ |n1992 1993Q19&4 Q1995 g1996 I 1 . e SI | ! 1 -5. i -9. l|||||'LrLL|'LrLL|l^rLLLjl|L|||| il|J ^1 ^ [U{|| e SI 1 "1' _£_ ^ -3 I i h 1 III ^^ L 1 1 PCB18 PCB44 PCB52 PCB101 SumPCB'0.1 PCB18 PCB44 PCB52 PCB101 SumPCB'0.1 IADN Results to 1996 Page 94 ------- Figure F7: Annual Average Wet Deposition Flux (ng/m2/d) of PAHs * 7992 -1994: B(b)F; 1995 - 1996: B(b+k)F t Lake Superior 11992 1993 Q1994 Q 1995 11 Lake Michigan Sv^t rrvrh PHEN PYR B(k)For B(a)P B(b+k)F* 11992 11993 Q 1994 Q1995 |19! I 20 PYR B(k)For B(a)P B(b+k)F' Q1992 B1993 Q1994 Q1995 11996 8- Q £ HHE B(k)For B(a)P B(b+k)F* 11992 B1993 Q1994 n 1995 B 1996 IADN Results to 1996 Page 95 ------- Figure F8: Annual Average Dry Deposition Flux (ng/m2/d) of PAHs * 7992 -1994: B(b)F; 1995 - 1996: B(b+k)F Lake Superior Lake Michigan s S n PHEN PYR rtn-n B(k)For B(a)P B(b+k)F* 11992 1993 Q 1994 Q 1995 11 1992 g 1993 Q 1994 Q1995 |1996 I a. PHEN PYR B(k)For B(a)P B(b+k)F' H 1992 1993 Q1994 Q1995 >1996 PYR B(k)For B(a)P B(b+k)F* PHEN PYR B(k)For B(b+k)F' 11992 B1993 Q1994 n 1995 B 1996 IADN Results to 1996 Page 96 ------- Figure F9: Annual Average Net Gas Exchange Flux (ng/m2/d) of PAHs (Positive values denote net gas absorption, negative values denote net volatilisation) * 1992 -1994: B(b)F; 1995 - 1996: B(b+k)F -50 -100 -150 -200 -250 Lake Superior ,n_ ft B(k)For B(b+k)P |1992 1993 Q1994 Q1995 11996 I £ B) ^ IL. & O -150 -200 -250 Data not available for Lake Michigan Data not available for Lake Huron B(k)For B(b+k)F* 1992 11993 Q 1994 FJ1995 ^1996 I Data not available for Lake Ontario IADN Results to 1996 Page 97 ------- Figure F10: Annual Average Wet Deposition Flux (ng/m2/d) of Metals Lake Superior .n 31992 D1993 D1994 D1995 D19 Data not available for Lake Michigan n-i-L. 1992 B1993 O1994 D1995 B19! Data not available for Lake Erie Lake Ontario 1992 199301994 D1995 119961 IADN Results to 1996 Page 98 ------- Figure Fll: Annual Average Dry Deposition Flux (ng/m2/d) of Metals Lake Superior Lake Michigan n h ,r-d~i .nTI II £ C g 1 Q O - - - rh-i-ri rn~L« 1994 Q1995 a 1996 I n1992 B1993 O1994 O1995 1996 Lake Erie Lake Ontario * 800 u. c I 600 S 400. _ fcE [1992 J1993 g1994 g1995 g1996 | 1992 H1993 Q1994 Q1995 ^1996 I IADN Results to 1996 Page 99 ------- IADN Results to 1996 Page 100 ------- |