Resources Dioxin Conceptual Model (Winters)

							Conceptual Model for Dioxin in the Environment

Dwain Winters Director Dioxin Policy Project Office of Pollution Prevention and Toxics 202 260 8558 Winters.dwain@epa.gov

April 22-24, 2002

PBT Monitoring Strategy Workshop

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Dioxin-Like Compounds
O Cl Cl Cl

Cl
Cl

Cl Cl

Cl
Cl O Cl Cl O Cl

Cl

Cl

2,3,7,8-Tetrachlorodibenzo-p-dioxin

2,3,7,8-Tetrachlorodibenzofuran

3,3',4,4',5,5'-Hexachlorobiphenyl

Dioxins 75 congeners 7 toxic
2,3,7,8-TCDD 1,2,3,7,8-PeCDD 1,2,3,4,7,8-HxCDD 1,2,3,6,7,8-HxCDD 1,2,3,7,8,9-HxCDD 1,2,3,4,6,7,8-HpCDD 1,2,3,4,6,7,8,9-OCDD

Furans 135 congeners 10 toxic
2,3,7,8-TCDF 1,2,3,7,8-PeCDF 2,3,4,7,8-PeCDF 1,2,3,4,7,8-HxCDF 1,2,3,6,7,8-HxCDF 1,2,3,7,8,9-HxCDF 2,3,4,6,7,8-HxCDF 1,2,3,4,6,7,8-HpCDF 1,2,3,4,7,8,9-HpCDF 1,2,3,4,6,7,8,9-OCDF
PBT Monitoring Strategy Workshop

PCBs 209 congeners 12 toxic
3,3',4,4'-TeCB 3,3',4,4',5-PeCB 3,3',4,4',5,5'-HxCB

April 22-24, 2002

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Dioxin-Like Compounds
• • • • • • Semivolatile Lipophilic Hydrophobic Persistent Bioaccumulating Toxics

April 22-24, 2002

PBT Monitoring Strategy Workshop

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Trace Levels --- Highly Toxic
• Soil, Food --- PPT
• Water --- PPQ • Air --- fg/m3 • Human Serum ---PPT • Intake --- 1pg/kg/d TEQ • Upper Bound Cancer Risk 1x10-3

• Non-Cancer MOE < 10

April 22-24, 2002

PBT Monitoring Strategy Workshop

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95% of Background Exposure From Commercial Food Supply
Vegetable fat Soil ingestion Soil dermal contact Other meats Poultry Pork Freshwater fish and shellfish

6% 5%

19%
Marine fish and shellfish

Beef

14%

7%
1%

Inhalation

4%
Eggs

16% 21%
Milk

Dairy
April 22-24, 2002 PBT Monitoring Strategy Workshop

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20th Century Trend
Sediment Levels, Beaver Lake, Olympic Peninsula, WA Non-detects = zero 200 180

Residue Levels (pg/g, dw)

160 140 120 100 80 60 40 20 0 1884 1897 1909 1921 1932 Year Total CDD/Fs 1946 1955 1964 1974.4

April 22-24, 2002

PBT Monitoring Strategy Workshop

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Inventory of Sources of Dioxin in the United States- Sept, 2000 draft
Municipal Solid Waste Incineration, air Backyard Barrel Burnning, air Medical Waste Incineration, air Secondary Copper Smelting, air Cement Kilns (haz waste), air Sewage Sludge/land applied, land Residential Wood Burning, air Coal-fired Utilities, air Diesel Trucks, air Secondary Aluminum Smelting, air 2,4-D, land Iron Ore Sintering, air Industrial Wood Burning, air Bleached Pulp and Paper Mills, water Cement Kilns (non-haz waste), air Sewage Sludge Incineration, air EDC/Vinyl chloride, air Oil-fired Utilities, air Crematoria, air Unleaded Gasoline, air Hazardous Waste Incineration, air Lightweight ag kilns, haz waste,air Kraft Black Liquor Boilers, air Petrol Refine Catalyst Reg., air Leaded Gasoline, air Secondary Lead Smelting, air Paper Mill Sludge, land Cigarette Smoke, air EDC/Vinyl chloride, land Primary Copper, air EDC/Vinyl chloride, water Boilers/industrial furnaces Tire Combustion, air Drum Reclamation, air TOTALS Percent Reduction from 1987

1987 Emissions (g TEQdfWHO98/yr)

1995 Emissions (g TEQdfWHO98/yr)

% Total 1995

8877.0 604.0 2590.0 983.0 117.8 76.6 89.6 50.8 27.8 16.3 33.4 32.7 26.4 356.0 13.7 6.1 NA 17.8 5.5 3.6 5.0 2.4 2.0 2.2 37.5 1.2 14.1 1.0 NA 0.5 NA 0.8 0.1 0.1 13,995

1250.0 628.0 488.0 271.0 156.1 76.6 62.8 60.1 35.5 29.1 28.9 28.0 27.6 19.5 17.8 14.8 11.2 10.7 9.1 5.9 5.8 3.3 2.3 2.2 2.0 1.7 1.4 0.8 0.7 0.5 0.4 0.4 0.1 0.1 3,252 77%

38% 19% 15% 8% 5% 2% 2% 2% 1% 1% 1% 1% 1% 1% 1% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

April 22-24, 2002

PBT Monitoring Strategy Workshop

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Inventory of Sources of Dioxin in the United States-May, 2000
Municipal Solid Waste Incineration, air Backyard Barrel Burnning, air Medical Waste Incineration, air Secondary Copper Smelting, air Cement Kilns (haz waste), air Sewage Sludge/land applied, land Residential Wood Burning, air Coal-fired Utilities, air Diesel Trucks, air Secondary Aluminum Smelting, air 2,4-D, land Iron Ore Sintering, air Industrial Wood Burning, air Bleached Pulp and Paper Mills, water Cement Kilns (non-haz waste), air Sewage Sludge Incineration, air EDC/Vinyl chloride, air Oil-fired Utilities, air Crematoria, air Unleaded Gasoline, air Hazardous Waste Incineration, air Lightweight ag kilns, haz waste,air Kraft Black Liquor Boilers, air Petrol Refine Catalyst Reg., air Leaded Gasoline, air Secondary Lead Smelting, air Paper Mill Sludge, land Cigarette Smoke, air EDC/Vinyl chloride, land EDC/Vinyl chloride, water Boilers/industrial furnaces, air Tire Combustion , air Drum Reclamation, air TOTALS Percent Reduction from 1987

1987 Emissions (g TEQdfWHO98/yr)

1995 2002/4 Emissions Emissions (g TEQdf- (g TEQdfWHO98/yr) WHO98/yr)

8877.0 604.0 2590.0 983.0 117.8 76.6 89.6 50.8 27.8 16.3 33.4 32.7 26.4 356.0 13.7 6.1 NA 17.8 5.5 3.6 5.0 2.4 2.0 2.2 37.5 1.2 14.1 1.0 NA NA 0.8 0.1 0.1 13,995

1250.0 628.0 488.0 271.0 156.1 76.6 62.8 60.1 35.5 29.1 28.9 28.0 27.6 19.5 17.8 14.8 11.2 10.7 9.1 5.9 5.8 3.3 2.3 2.2 2.0 1.7 1.4 0.8 0.7 0.4 0.4 0.1 0.1 3,252 77%

12.0 628.0 7.0 5.0 7.7 76.6 62.8 60.1 35.5 29.1 28.9 28.0 27.6 12.0 17.8 14.8 11.2 10.7 9.1 5.9 3.5 0.4 2.3 2.2 2.0 1.7 1.4 0.8 0.7 0.4 0.4 0.1 0.1 1,106 92%

April 22-24, 2002

PBT Monitoring Strategy Workshop

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1987 1995 2004
O fi r ed ED Ut ili Se C/ ti e Vi w ag s, ny e ai lc Sl r Ce hl ud m or en ge id Bl tK e, In ea ai iln ci ch r ne s ed ra (n ti o on Pu n, -h lp az ai an r w d as Pa In te pe du ), rM ai st r ri a ill lW s, w oo at d er I ro Bu n rn O in re Se g, Si co ai nt r nd er in ar g, y Al ai um r 2, in 4D, um la Sm nd el ti n Di g, es ai el r Co Tr Re al uc -fi si ks re de ,a d Se nt ir Ut w ia ili ag lW ti e e oo Sl s, ud d ai r Bu ge rn /la Ce in nd m g, en ap tK ai Se pl r iln co ie d, s nd (h la ar az nd y Co w M as ed pp te ic er ), al ai Sm W r as el Ba M ti n te ck un In g, ya ic ci rd ai ip ne r al Ba ra So rre ti o lB lid n, ur ai W nn r as in te g, In ci ai ne r ra ti o n, ai r il-

Major US Dioxin Sources

0.0

1000.0

2000.0

3000.0

4000.0

5000.0

6000.0

7000.0

8000.0

9000.0

Reservoir Sources
• Old releases of dioxins that are temporarily stored in environmental compartments to later be reintroduced into the circulating environment • Contribute as much as 50% of general population
• Dioxin-like PCBs more than a third of total risk • Fish likely to be dominated by sediment reservoirs.

April 22-24, 2002

PBT Monitoring Strategy Workshop

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Sources and Pathways to Human Exposures
SOURCES TRANSPORT DEPOSITION FOOD SUPPLY

Reentrainment Runoff Erosion

Average Annual Dioxin Air Concentration
National Dioxin Ambient Monitoring Network year 2000

Dioxin Environmental Mobility
• Dioxins are less mobile than Hg or the more volatile PCBs.
• Dioxins do not appear to exhibit global retort, or strong “grasshopper” effect. • Dioxins are continually exchanged among media and should be viewed as a complex system of stocks and flows

April 22-24, 2002

PBT Monitoring Strategy Workshop

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Fluxes among dioxin reservoirs

Monitoring Activities
• Air monitoring (NDAMN) provides direct near term measure of source reduction in air emissions. (EPA) • Food provides the most direct measure of current exposure. (FDA, USDA, and EPA) • Blood serum best long term measure of reducing risk. (CDC) • Baseline monitoring needs include: National soil survey National sediment survey.

April 22-24, 2002

PBT Monitoring Strategy Workshop

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Monitoring and Modeling
A Major Opportunity for Analytical Tool Development • 2000 Release Inventory • 2000 NDAMN Data • Air transport Models

April 22-24, 2002

PBT Monitoring Strategy Workshop

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