Mark Mahoney – EPA New EnglandMark Mahoney – EPA New England

Dioxin and Dioxin and Backyard Backyard BurningBurning

Vermont Forum on Open BurningVermont Forum on Open BurningMay 17, 2004May 17, 2004

22

TopicsTopics

What is dioxin?What is dioxin? Why is dioxin a unique pollutant?Why is dioxin a unique pollutant? Health EffectsHealth Effects Exposure PathwaysExposure Pathways Environmental SourcesEnvironmental Sources Importance of Barrell BurningImportance of Barrell Burning

33

Some consider this an issue of the past.

44

55

66

77

88

State-of-the-Art Burn BoxState-of-the-Art Burn Box

99

Why are we Concerned?Why are we Concerned?

Backyard burning causes accidental fires.Backyard burning causes accidental fires.

Backyard burning releases toxic chemicals Backyard burning releases toxic chemicals into environment that can cause adverse into environment that can cause adverse health impacts.health impacts.

Backyard burning is illegal in Backyard burning is illegal in many states and counties.many states and counties.

1010

Release of Toxic ChemicalsRelease of Toxic Chemicals

Particulate MatterParticulate Matter Sulfur DioxideSulfur Dioxide Carbon MonoxideCarbon Monoxide PAHsPAHs Metals Metals HexacholorobenzeneHexacholorobenzene DioxinDioxin

Direct Exposure

Indirect Exposure

1111

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

Cl

Cl

Cl

Cl

O

O

PCBs209 congeners

12 toxic

3,3',4,4'-TeCB3,3',4,4',5-PeCB3,3',4,4',5,5'-HxCBPlus 8 others

Cl

Cl

Cl

Cl

Cl

Cl

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

Dioxin-like CompoundsDioxin-like Compounds

Dioxins75 congeners

7 toxic

2,3,7,8-TCDD1,2,3,7,8-PeCDD1,2,3,4,7,8-HxCDD1,2,3,6,7,8-HxCDD1,2,3,7,8,9-HxCDD1,2,3,4,6,7,8-HpCDD1,2,3,4,6,7,8,9-OCDD

Furans135 congeners

10 toxic

2,3,7,8-TCDF1,2,3,7,8-PeCDF2,3,4,7,8-PeCDF1,2,3,4,7,8-HxCDF1,2,3,6,7,8-HxCDF1,2,3,7,8,9-HxCDF2,3,4,6,7,8-HxCDF1,2,3,4,6,7,8-HpCDF1,2,3,4,7,8,9-HpCDF1,2,3,4,6,7,8,9-OCDF

Cl

Cl

Cl

Cl

2,3,7,8-Tetrachlorodibenzofuran

O

1212

What is Dioxin?What is Dioxin?

A group of chlorinated organic compounds A group of chlorinated organic compounds including dioxins, furans, and some PCBs.including dioxins, furans, and some PCBs.

Produced when materials containing Produced when materials containing chlorine are burnedchlorine are burned

Occur naturally and from combustion of Occur naturally and from combustion of fuels & waste, paper making, and other fuels & waste, paper making, and other chemical and industrial processes.chemical and industrial processes.

1313

USEPA’s Dioxin ReassessmentUSEPA’s Dioxin Reassessment

The Good News:The Good News:The average bioaccumulation level in humans has dropped The average bioaccumulation level in humans has dropped

from 55 ppt (in the 1980’s) to 25 ppt (1990’s)from 55 ppt (in the 1980’s) to 25 ppt (1990’s) The Bad News:The Bad News:

The level at which health effects are detectable in humans is The level at which health effects are detectable in humans is considerably lower than previously estimated. considerably lower than previously estimated. Consequently, current exposures are still of concern.Consequently, current exposures are still of concern.

The Bottom Line:The Bottom Line:We need to take more steps to further reduce dioxin We need to take more steps to further reduce dioxin

exposure.exposure.

Key Findings of the Reassessment:Key Findings of the Reassessment:

• 95% of General Population Exposure is from animal fats in the 95% of General Population Exposure is from animal fats in the commercial food supplycommercial food supply Local sources make little contribution to most peoples’ exposureLocal sources make little contribution to most peoples’ exposure Environmental levels in meat and dairy production areas major contributorEnvironmental levels in meat and dairy production areas major contributor

• Air deposition onto plants consumed by domestic meat and dairy animals Air deposition onto plants consumed by domestic meat and dairy animals is the principal route for contamination of commercial food supplyis the principal route for contamination of commercial food supply

• Reservoir sources are a significant component of current exposure and Reservoir sources are a significant component of current exposure and may dominate future exposuremay dominate future exposure

8

DRE TATA

Altered gene expression

TCDD, ...

Co-activatorsCo-repressors

Arn

t

AhR

hsp90

mRNA

Changes in protein levels(e.g., CYPIA1, IL-1, ...)

Differentiationand

Proliferation

hsp90

RB, ... HIF, Sim,...

chromatin

phosphorylation/dephosphorylation

ClClCl ClO

O

ClClCl ClO

O

ClClCl ClO

O

ClClCl ClO

OArn

t

Ah

R

BT

Fs BT

Fs

hsp90 AIP,..

Tran

spor

t

Mec

hani

sm

Other Proteins

AIP,..hsp90

Modes of Action of Dioxin

1616

Toxic Effects of DioxinsToxic Effects of Dioxins

LethalityLethality WastingWasting Gonadal/Lymphoid Gonadal/Lymphoid

AtrophyAtrophy HyperplasiaHyperplasia MetaplasiaMetaplasia Endocrine disruptionEndocrine disruption CarcinogenicityCarcinogenicity

Reproductive/ Reproductive/ Developmental Developmental toxicitytoxicity

Dermal toxicityDermal toxicity ImmunotoxicityImmunotoxicity NeurotoxicityNeurotoxicity Hepatic toxicityHepatic toxicity Cardiovascular Cardiovascular

toxicitytoxicity

Multiple effects in multiple tissues of both sexes of multiple species throughout the

vertebrate kingdom

Key Findings of the Reassessment Key Findings of the Reassessment

• Adverse non-cancer effects have been Adverse non-cancer effects have been observed in animal and humans within 10 observed in animal and humans within 10 times background exposure. It is likely that times background exposure. It is likely that part of the general population is at, or near, part of the general population is at, or near, exposure levels where adverse effects can be exposure levels where adverse effects can be anticipated.anticipated.

9

• Cancer slope factor is based primarily on published analyses Cancer slope factor is based primarily on published analyses of human studies and is revised upward by a factor of ~6 over of human studies and is revised upward by a factor of ~6 over the 1985 EPA value. Uncertainty in the value but MOEs for the 1985 EPA value. Uncertainty in the value but MOEs for cancer are low.cancer are low.

Based on epidemiologic data, probability of cancer risk to the Based on epidemiologic data, probability of cancer risk to the general population may exceed 10general population may exceed 10-3-3 (1 in 1,000) from (1 in 1,000) from background (dietary) exposure. “True” risks are likely to be background (dietary) exposure. “True” risks are likely to be less but we can’t say how much less but may approach zero less but we can’t say how much less but may approach zero for some individuals (very low exposure/very low for some individuals (very low exposure/very low susceptibility).susceptibility).

Key Findings of the Reassessment: Key Findings of the Reassessment: Risk CharacterizationRisk Characterization

10

• Current US regulatory efforts have addressed most of the Current US regulatory efforts have addressed most of the known large industrial sources (~80% reduction between ’87 known large industrial sources (~80% reduction between ’87 and ’95; further reductions (>90%) anticipated).and ’95; further reductions (>90%) anticipated).

• Open burning of household wastes is the biggest unaddressed Open burning of household wastes is the biggest unaddressed contemporary source identified so far.contemporary source identified so far.

• There remain There remain many uncharacterized sourcesmany uncharacterized sources that could be that could be significant (agricultural burning, ceramics, forest fires, significant (agricultural burning, ceramics, forest fires, secondary steel, reservoir sources). secondary steel, reservoir sources).

Key Findings of the Reassessment:

7

2020

Reentrainment

SOURCES

TRANSPORT

DEPOSITION FOODSUPPLY

RunoffErosion

Sources and Pathways to Human Exposures

Fluxes Fluxes amongamongdioxin dioxin reservoirsreservoirs

2222

Pathways:Pathways: Ingestion of soil, meats, dairy products, fish Ingestion of soil, meats, dairy products, fish Inhalation of vapors and particulatesInhalation of vapors and particulates Dermal contact with soilDermal contact with soil

Sources:Sources: CombustionCombustion Metal Smelting, Refining, ProcessingMetal Smelting, Refining, Processing Chemical manufacturingChemical manufacturing Biological and Photochemical ProcessesBiological and Photochemical Processes Reservoir sourcesReservoir sources

Pathways and Sources of Human Exposures

2323

Environmental levels: Peaked in late 60s/early 70s; declined since

based on sediment data Decline also supported by Emissions Inventory which shows significant decrease from 1987 to 1995 (~80%)

Human tissue data suggest current levels are about half of 1980 levels (55 to 25 pg TEQDFP/g lipid)

Steady state PK modeling of current intake levels project tissue levels of about 11 pg TEQDFP/g lipid.

Dioxin Exposure Trends

2424

Data for Archived Food SamplesData for Archived Food Samples

Description PCDD/FTEQ, pg/g

lipid

PCB TEQ,pg/g lipid

Percentdifference

from currentPCDD/F

levels

Percentdifference

from currentPCB levels

1908 beef ration 0.34 (0.15) 0.07 (0.07) 38 (42) 15 (15)

1945 beef and pork 0.98 (0.75) 0.36 (0.36) 89 (197) 140 (146)

1957 dried cream 2.05 (0.81) 3.56 (3.54) 244 (96) 827 (824)

1968 bacon bar 3.01 (2.94) 1.05 (1.05) 231 (638) 1747 (2620)

1968 deviled ham 3.73 (3.71) 0.61 (0.61) 287 (805) 1019 (1529)

1971 beef 1.36 (0.02) 2.48 (1.98) 153 (7) 540 (540)

1971 bacon wafer 1.75 (1.62) 1.98 (1.98) 135 (352) 3301 (4952)

1977 raw chicken 1.29 (1.18) 2.72 (2.72) 202 (287) 970 (970)

1977 cooked chicken 1.33 (1.20) 2.83 (2.83) 209 (292) 1009 (1009)

1979 pork slices 1.46 (1.20) 0.04 (0.04) 112 (262) 72 (105)

1980 beef steak 0.94 (0.73) 0.93 (0.93) 106 (207) 203 (203)

1982 ham slice 1.36 (1.04) 0.07 (0.07) 105 (227) 119 (178)

1983 beef in bbq 0.50 (0.03) 0.79 (0.79) 56 (8) 171 (171)

1983 turkey with gravy 0.55 (0.23) 0.32 (0.31) 85 (57) 113 (113)

Description

lipidpg/g lipid

levelsPCB levels

1908 beef ration 0.34 (0.15) 0.07 (0.07) 38 (42) 15 (15)

1945 beef and pork 0.98 (0.75) 0.36 (0.36) 89 (197) 140 (146)

1957 dried cream 2.05 (0.81) 3.56 (3.54) 244 (96) 827 (824)

1968 bacon bar 3.01 (2.94) 1.05 (1.05) 231 (638) 1747 (2620)

1968 deviled ham 3.73 (3.71) 0.61 (0.61) 287 (805) 1019 (1529)

1971 beef 1.36 (0.02) 2.48 (1.98) 153 (7) 540 (540)

1971 bacon wafer 1.75 (1.62) 1.98 (1.98) 135 (352) 3301 (4952)

1977 raw chicken 1.29 (1.18) 2.72 (2.72) 202 (287) 970 (970)

1977 cooked chicken 1.33 (1.20) 2.83 (2.83) 209 (292) 1009 (1009)

1979 pork slices 1.46 (1.20) 0.04 (0.04) 112 (262) 72 (105)

1980 beef steak 0.94 (0.73) 0.93 (0.93) 106 (207) 203 (203)

1982 ham slice 1.36 (1.04) 0.07 (0.07) 105 (227) 119 (178)

1983 beef in bbq 0.50 (0.03) 0.79 (0.79) 56 (8) 171 (171)

1983 turkey with gravy 0.55 (0.23) 0.32 (0.31) 85 (57) 113 (113)

(results assume ND = ½ LOD; results calculated at ND = 0 shown in parenthesis).

2525

2000 Draft Estimate: ~ 65 pg TEQDFP-WHO98/day

21%16%

19%

14%

5%

4%

7%

6%

1%

Soil ingestionSoil dermal contact

Freshwater fish andshellfish

Marine fish and shellfish

Inhalation

Milk

Dairy

Eggs

Beef

Pork

Poultry

Other meats Vegetable fat

Adult Average Daily Intake of Adult Average Daily Intake of CDDs/CDFs/Dioxin-like PCBsCDDs/CDFs/Dioxin-like PCBs

2626

Location of Lakes for Sediment Location of Lakes for Sediment Core SamplingCore Sampling

SE-4

RM-7RM-11

RM-12

A-4

NE-4

NE-11

SE-2

NE-5W-15

W-14

SE-4

RM-7RM-11

RM-12

A-4

NE-4

NE-11

SE-2

NE-5W-15

W-14

2727

Non-detects = zero

0

20

40

60

80

100

120

140

160

180

200

197419641955194619321921190918971884Year

Re

sid

ue

Lev

els

(pg/

g, d

w)

Total CDD/Fs

Sediment Levels, Beaver Lake, Olympic PeninsulaSediment Levels, Beaver Lake, Olympic Peninsula

2828

Inventory of Sources of Dioxin in the United States- Sept, 2000 draft

1987 Emissions (g TEQdf-

WHO98/yr)

1995 Emissions (g TEQdf-

WHO98/yr) % Total

1995

Municipal Solid Waste Incineration, air 8877.0 1250.0 38%Backyard Barrel Burnning, air 604.0 628.0 19%Medical Waste Incineration, air 2590.0 488.0 15%Secondary Copper Smelting, air 983.0 271.0 8%Cement Kilns (haz waste), air 117.8 156.1 5%Sewage Sludge/land applied, land 76.6 76.6 2%Residential Wood Burning, air 89.6 62.8 2%Coal-fired Utilities, air 50.8 60.1 2%Diesel Trucks, air 27.8 35.5 1%Secondary Aluminum Smelting, air 16.3 29.1 1%2,4-D, land 33.4 28.9 1%Iron Ore Sintering, air 32.7 28.0 1%Industrial Wood Burning, air 26.4 27.6 1%Bleached Pulp and Paper Mills, water 356.0 19.5 1%Cement Kilns (non-haz waste), air 13.7 17.8 1%Sewage Sludge Incineration, air 6.1 14.8 0%EDC/Vinyl chloride, air NA 11.2 0%Oil-fired Utilities, air 17.8 10.7 0%Crematoria, air 5.5 9.1 0%Unleaded Gasoline, air 3.6 5.9 0%Hazardous Waste Incineration, air 5.0 5.8 0%Lightweight ag kilns, haz waste,air 2.4 3.3 0%Kraft Black Liquor Boilers, air 2.0 2.3 0%Petrol Refine Catalyst Reg., air 2.2 2.2 0%Leaded Gasoline, air 37.5 2.0 0%Secondary Lead Smelting, air 1.2 1.7 0%Paper Mill Sludge, land 14.1 1.4 0%Cigarette Smoke, air 1.0 0.8 0%EDC/Vinyl chloride, land NA 0.7 0%Primary Copper, air 0.5 0.5 0%EDC/Vinyl chloride, water NA 0.4 0%Boilers/industrial furnaces 0.8 0.4 0%Tire Combustion, air 0.1 0.1 0%Drum Reclamation, air 0.1 0.1 0%TOTALS 13,995 3,252 Percent Reduction from 1987 77%

2929

Inventory of Sources of Dioxin in the United States-May, 2000

1987 Emissions (g TEQdf-

WHO98/yr)

1995 Emissions (g TEQdf-

WHO98/yr)

2002/4 Emissions (g TEQdf-

WHO98/yr)

Municipal Solid Waste Incineration, air 8877.0 1250.0 12.0Backyard Barrel Burnning, air 604.0 628.0 628.0Medical Waste Incineration, air 2590.0 488.0 7.0Secondary Copper Smelting, air 983.0 271.0 5.0Cement Kilns (haz waste), air 117.8 156.1 7.7Sewage Sludge/land applied, land 76.6 76.6 76.6Residential Wood Burning, air 89.6 62.8 62.8Coal-fired Utilities, air 50.8 60.1 60.1Diesel Trucks, air 27.8 35.5 35.5Secondary Aluminum Smelting, air 16.3 29.1 29.12,4-D, land 33.4 28.9 28.9Iron Ore Sintering, air 32.7 28.0 28.0Industrial Wood Burning, air 26.4 27.6 27.6Bleached Pulp and Paper Mills, water 356.0 19.5 12.0Cement Kilns (non-haz waste), air 13.7 17.8 17.8Sewage Sludge Incineration, air 6.1 14.8 14.8EDC/Vinyl chloride, air NA 11.2 11.2Oil-fired Utilities, air 17.8 10.7 10.7Crematoria, air 5.5 9.1 9.1Unleaded Gasoline, air 3.6 5.9 5.9Hazardous Waste Incineration, air 5.0 5.8 3.5Lightweight ag kilns, haz waste,air 2.4 3.3 0.4Kraft Black Liquor Boilers, air 2.0 2.3 2.3Petrol Refine Catalyst Reg., air 2.2 2.2 2.2Leaded Gasoline, air 37.5 2.0 2.0Secondary Lead Smelting, air 1.2 1.7 1.7Paper Mill Sludge, land 14.1 1.4 1.4Cigarette Smoke, air 1.0 0.8 0.8EDC/Vinyl chloride, land NA 0.7 0.7EDC/Vinyl chloride, water NA 0.4 0.4Boilers/industrial furnaces, air 0.8 0.4 0.4Tire Combustion , air 0.1 0.1 0.1Drum Reclamation, air 0.1 0.1 0.1TOTALS 13,995 3,252 1,106 Percent Reduction from 1987 77% 92%

3030

Known Sources of DioxinKnown Sources of Dioxin

0

200

400

600

800

1000

1200

1400

Dio

xin

Em

issi

on

s (g

TE

Qd

f-W

HO

98/y

r)

1995

2002/04

3131

BYB Emissions are Greater Than All BYB Emissions are Greater Than All Other Quantified Sources CombinedOther Quantified Sources Combined

BYB

All othersources

3232

OPEN BURNING TEST FACILITY

3333

Open Burn Test FacilityOpen Burn Test Facility

3434

Results: TEQ ValuesResults: TEQ Values

Ba

se

lin

e

Ba

se

lin

e

Ba

se

lin

e

Ba

se

lin

e

Ba

se

lin

e

Ba

se

lin

e

Ba

se

lin

e

PV

C=

0%

PV

C=

0%

PV

C=

1%

PV

C=

1%

Co

mp

res

se

d

Co

mp

res

se

d

Do

ub

le

Do

ub

le

Do

ub

le

We

tte

d

We

tte

d

Op

en

PV

C=

7.5

%

PV

C=

7.5

%

Ca

Cl2

Ca

Cl2

Hig

h C

u

Hig

h C

u1

10

100

1000

10000

I-T

EQ

(n

g/k

g w

as

te b

urn

ed

)

3535

Statistical Analysis ResultsStatistical Analysis Results

Waste Chlorine Effect Statistically Significant Waste Chlorine Effect Statistically Significant Only at High Cl LevelsOnly at High Cl Levels

At Normal Cl Levels (< 1 % Cl), Other At Normal Cl Levels (< 1 % Cl), Other Parameters DominateParameters Dominate

Gas-Phase Conditions Important (HCl, T, Cu, Gas-Phase Conditions Important (HCl, T, Cu, burning rate)burning rate)

Majority of PCDD/F Emissions During Majority of PCDD/F Emissions During Smoldering Phase of BurnSmoldering Phase of Burn

3636

-In 2000, 51.8 Million People Lived in Nonmetropolitan Areas (U.S. DOC, 2000).

-Of the Rural Population in the United States, 40 Percent Are Assumed to Burn Their Household Waste in a Barrel (Two Rivers Region Council of Public Officials 1994).

-On Average, Each U.S. Citizen Generates 4.5 Pounds of Solid Waste (Excluding Yard Waste) Per Day (or 616 kg/person-yr) (U.S. EPA, 2001).

-On Average, in Households that Dispose of Household Waste by Burning, Approximately 63 Percent of Waste Generated Is Burned (I.E., 63 Percent of 616 Kg/person-yr = 388 Kg/person-year) (Two Rivers Region Council of Public Officials 1994).

Activity LevelActivity Level

3737

Dioxin Uptake Into Meat And Dioxin Uptake Into Meat And DairyDairy

3838

Emissions from Known Sources Unlikely to Correlate Proportionally With General Population Exposures.

•A Majority of the Combustion Sources Are Limited to a Few States

•The Production of Animal Fats Is Also Concentrated in a Few States

•Most Major Food Production States Are Are Upwind of Major Emission Production States

•Open Burning Likely to be a Significant Source of Exposure

•Reservoir Sources Could Be Significant Source of Exposure

3939

UncontrolledUncontrolled ControlledControlled

4040

Dioxin-like Compounds are Highly Potent Carcinogens and exhibit a wide range on non-cancer health effects.

Dioxin-like Compounds Background exposure levels result in significant risk.

Exposure is from consumption of animal fats in the commercial food supply.

Environmental levels have declined since the '70s but may level off as major industrial emission sources are controlled.

Uncontrolled combustion is likely to be the largest unaddressed contemporary sources.

Backyard burning of household waste is the best understood and

likely the most amenable to reduction of all uncontrolled combustion sources.

Summary and Conclusions

4141

What Can YOU Do?What Can YOU Do?

Share the messageShare the message Identify other waste disposal methods in your Identify other waste disposal methods in your

communitycommunity Reuse (more use means less waste)Reuse (more use means less waste) Recycle (paper, plastics, metallic items) Recycle (paper, plastics, metallic items) Compost (leaves, yard waste, vegetable wastes)Compost (leaves, yard waste, vegetable wastes) Identify local landfills which accept wasteIdentify local landfills which accept waste

Together we can :Together we can :“Ban the Barrel”“Ban the Barrel”

Thank youThank you