Waste-to-Energy Facilities: MSW and Wood-waste
Waste-to-Energy Facilities: MSW and Wood-waste Health Risk Assessments Laura Green, Ph.D., D.A.B.T. Stephen Zemba, Ph.D., P.E. Michael Ames, Sc. D. July 21, 2010
Cambridge Environmental Inc
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Columbus, Ohio
Harrisburg, PA
Cambridge Environmental Inc
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Why were emissions from W-to-E facilities of concern?
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Primarily because of one family of pollutants . . .
Cambridge Environmental Inc
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Cambridge Environmental Inc
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Why are/were PCDD/F’s emitted from W-to-E facilities?
Cambridge Environmental Inc
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Because of the Law of Unintended Consequences . . .
Cambridge Environmental Inc
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Cambridge Environmental Inc
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How have things changed . . . ?
Cambridge Environmental Inc
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Annual Emissions to Atmosphere (g,yr, TEQ
DF -WHO 98 )
PCDD/PCDF Emissions in the U.S. 16000 14000 12000 10000 8000 6000
4000 2000
0 1987
Municipal waste combustors
1995 Medical waste incinerators
Cambridge Environmental Inc
2000 Backyard barrel burning
www.CambridgeEnvironmental.com
Other sources # 10
Likewise, our daily intakes of ―dioxins‖ have fallen dramatically over the decades . . .
Cambridge Environmental Inc
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Cambridge Environmental Inc
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PCDD/F, max. impacts, ambient air Columbus, OH W-to-E
Haverhill and North Andover, MA W-to-E’s
1,700 fg/m3
2 fg/m3
(MA DEP) Harrisburg, PA W-to-E
Typical Background
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0.2 fg/m3
15 fg/m3
www.CambridgeEnvironmental.com
Fate and transport of emitted dioxins (& other pollutants) ...
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Pollutant Emissions Air Dispersion and Deposition Source, Fate, and Transport Modeling
Soil and Vegetation
Surface Water and Sediment
Meat and Dairy
Fish
Exposure and Toxicity Assessment
Cambridge Environmental Inc
People and Wildlife
www.CambridgeEnvironmental.com
# 15
How do we estimate concentrations in these media?
Use a series of models: deposition, mixing, partitioning, uptake, bioaccumulation . . .
Cambridge Environmental Inc
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Calculate soil concentrations of emitted COCs:
CstD
Ds 1 exp ks tD ks
where: Cs Ds ks tD T1 CstD
Average soil concentration over exposure duration (mg COC/kg soil); Deposition term (mg COC/kg soil/yr); COC soil loss constant due to all processes (yr–1); Time period over which deposition occurs (time period of combustion) (yr); Time period at the beginning of combustion (yr); Soil concentration at time tD (mg/kg).
Cambridge Environmental Inc
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How to we estimate risks to health there from?
We extrapolate far below range of observable health-effects Let’s look at some dose-response data . . .
Cambridge Environmental Inc
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Liver tumors in laboratory rats exposed to 2,3,7,8-TCDD 0.7 NTP 521 Kociba
Probability of tumor .
0.6 0.5 0.4 0.3 0.2 0.1 0 0
20,000
40,000
60,000
80,000
100,000
Dose rate pg/kg-day
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
120,000
Liver tumors in laboratory rats exposed to 2,3,7,8-TCDD . . . Low-dose range 0.35 NTP 521 Kociba
Probability of tumor .
0.3 0.25 0.2 0.15 0.1 0.05 0 0
5,000
10,000
15,000
Dose rate pg/kg-day
Cambridge Environmental Inc
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20,000
For whom do we estimate health-risks?
Residents (adults, children, nursing infants) Farmers Subsistence Fishers
Cambridge Environmental Inc
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Harrisburg, PA W-to-E Receptor
Exposure Pathways
Resident
Inhalation Max. offsite Ingestion of home-grown produce, impact drinking water, breast milk, soil
Farmer
Ibid. + Home-raised meats and eggs
Fisher
Ibid. + Ingestion of locally-derived fish Max. at water body
Cambridge Environmental Inc
Location
Max. at hypothetical farm
www.CambridgeEnvironmental.com
Harrisburg, PA W-to-E results Incremental cancer risk estimate Resident
1 in 10,000,000
Farmer
7 in 100,000,000
Fisher
1 in 10,000,000
Principal risk drivers: Dioxins/furans, As, PCBs, Cr VI Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Hazard Index Receptor (health effects other than cancer)
Principal Risk Drivers
Resident
0.01
Hg++, PCBs, Mn, Ni
Farmer
0.03
Hg++, Mn, Ni
Fisher
0.01
PCBs, Mn, CH3Hg
Cambridge Environmental Inc
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Proposed C&D/wood-to-Energy facility
Plainfield, CT
Plainfield, CT Renewable Energy Health Risk Assessment
Stephen Zemba, Ph.D., P.E. May 2008
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Scope of Assessment
78 emitted chemicals 29 metals/inorganic compounds 49 organic compounds Compared facility impacts both to background and to Hazard Limiting Values (HLVs)
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
3
Lead Concentrations (µg/m ) in Connecticut Air 1.2
1.1
1 0.8 Impacts Due to Plainfield Renewable Energy at Maximum Permit Levels
0.6 0.4 0.18
0.2
0.012
0.0022
0.00044
Current background level
Worst-case point
Plainfield Center
0 1970's level
1980's level
Cambridge Environmental Inc
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3
Arsenic Concentrations (µg/m ) in Connecticut Air 0.0018
0.0015
0.0012
0.0009
Impacts Due to Plainfield Renewable Energy at Maximum Permit Levels
0.0006
0.0003
0 Bridgeport
Groton
Hartford
Cambridge Environmental Inc
Manchester Voluntown Wallingford Waterbury Worst-case Point
www.CambridgeEnvironmental.com
Plainfield Center
Results of Health Risk Assessment
Max. impact Incremental 1 in Cancer Risk 1,000,000 Hazard Index
0.3
Cambridge Environmental Inc
Populated Risk drivers area 2 in 10,000,000
As, Cr VI, benzene
0.06
H2SO4, acrolein, Cl2, Mn
www.CambridgeEnvironmental.com
So, there was a time and a place — Columbus OH, early 1980’s — when Waste-to-Energy Facilities posed unacceptable risks to the environment and to public health . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
That time has passed . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Other states – PA, CT, ME, etc.–
have long since recognized this . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Massachusetts?
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Not yet . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Columbus, Ohio
Harrisburg, PA
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Why were emissions from W-to-E facilities of concern?
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Primarily because of one family of pollutants . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Why are/were PCDD/F’s emitted from W-to-E facilities?
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Because of the Law of Unintended Consequences . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
How have things changed . . . ?
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Annual Emissions to Atmosphere (g,yr, TEQ
DF -WHO 98 )
PCDD/PCDF Emissions in the U.S. 16000 14000 12000 10000 8000 6000
4000 2000
0 1987
Municipal waste combustors
1995 Medical waste incinerators
Cambridge Environmental Inc
2000 Backyard barrel burning
www.CambridgeEnvironmental.com
Other sources # 10
Likewise, our daily intakes of ―dioxins‖ have fallen dramatically over the decades . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
PCDD/F, max. impacts, ambient air Columbus, OH W-to-E
Haverhill and North Andover, MA W-to-E’s
1,700 fg/m3
2 fg/m3
(MA DEP) Harrisburg, PA W-to-E
Typical Background
Cambridge Environmental Inc
0.2 fg/m3
15 fg/m3
www.CambridgeEnvironmental.com
Fate and transport of emitted dioxins (& other pollutants) ...
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Pollutant Emissions Air Dispersion and Deposition Source, Fate, and Transport Modeling
Soil and Vegetation
Surface Water and Sediment
Meat and Dairy
Fish
Exposure and Toxicity Assessment
Cambridge Environmental Inc
People and Wildlife
www.CambridgeEnvironmental.com
# 15
How do we estimate concentrations in these media?
Use a series of models: deposition, mixing, partitioning, uptake, bioaccumulation . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Calculate soil concentrations of emitted COCs:
CstD
Ds 1 exp ks tD ks
where: Cs Ds ks tD T1 CstD
Average soil concentration over exposure duration (mg COC/kg soil); Deposition term (mg COC/kg soil/yr); COC soil loss constant due to all processes (yr–1); Time period over which deposition occurs (time period of combustion) (yr); Time period at the beginning of combustion (yr); Soil concentration at time tD (mg/kg).
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
How to we estimate risks to health there from?
We extrapolate far below range of observable health-effects Let’s look at some dose-response data . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Liver tumors in laboratory rats exposed to 2,3,7,8-TCDD 0.7 NTP 521 Kociba
Probability of tumor .
0.6 0.5 0.4 0.3 0.2 0.1 0 0
20,000
40,000
60,000
80,000
100,000
Dose rate pg/kg-day
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
120,000
Liver tumors in laboratory rats exposed to 2,3,7,8-TCDD . . . Low-dose range 0.35 NTP 521 Kociba
Probability of tumor .
0.3 0.25 0.2 0.15 0.1 0.05 0 0
5,000
10,000
15,000
Dose rate pg/kg-day
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
20,000
For whom do we estimate health-risks?
Residents (adults, children, nursing infants) Farmers Subsistence Fishers
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Harrisburg, PA W-to-E Receptor
Exposure Pathways
Resident
Inhalation Max. offsite Ingestion of home-grown produce, impact drinking water, breast milk, soil
Farmer
Ibid. + Home-raised meats and eggs
Fisher
Ibid. + Ingestion of locally-derived fish Max. at water body
Cambridge Environmental Inc
Location
Max. at hypothetical farm
www.CambridgeEnvironmental.com
Harrisburg, PA W-to-E results Incremental cancer risk estimate Resident
1 in 10,000,000
Farmer
7 in 100,000,000
Fisher
1 in 10,000,000
Principal risk drivers: Dioxins/furans, As, PCBs, Cr VI Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Hazard Index Receptor (health effects other than cancer)
Principal Risk Drivers
Resident
0.01
Hg++, PCBs, Mn, Ni
Farmer
0.03
Hg++, Mn, Ni
Fisher
0.01
PCBs, Mn, CH3Hg
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Proposed C&D/wood-to-Energy facility
Plainfield, CT
Plainfield, CT Renewable Energy Health Risk Assessment
Stephen Zemba, Ph.D., P.E. May 2008
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Scope of Assessment
78 emitted chemicals 29 metals/inorganic compounds 49 organic compounds Compared facility impacts both to background and to Hazard Limiting Values (HLVs)
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
3
Lead Concentrations (µg/m ) in Connecticut Air 1.2
1.1
1 0.8 Impacts Due to Plainfield Renewable Energy at Maximum Permit Levels
0.6 0.4 0.18
0.2
0.012
0.0022
0.00044
Current background level
Worst-case point
Plainfield Center
0 1970's level
1980's level
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
3
Arsenic Concentrations (µg/m ) in Connecticut Air 0.0018
0.0015
0.0012
0.0009
Impacts Due to Plainfield Renewable Energy at Maximum Permit Levels
0.0006
0.0003
0 Bridgeport
Groton
Hartford
Cambridge Environmental Inc
Manchester Voluntown Wallingford Waterbury Worst-case Point
www.CambridgeEnvironmental.com
Plainfield Center
Results of Health Risk Assessment
Max. impact Incremental 1 in Cancer Risk 1,000,000 Hazard Index
0.3
Cambridge Environmental Inc
Populated Risk drivers area 2 in 10,000,000
As, Cr VI, benzene
0.06
H2SO4, acrolein, Cl2, Mn
www.CambridgeEnvironmental.com
So, there was a time and a place — Columbus OH, early 1980’s — when Waste-to-Energy Facilities posed unacceptable risks to the environment and to public health . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
That time has passed . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Other states – PA, CT, ME, etc.–
have long since recognized this . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Massachusetts?
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
Not yet . . .
Cambridge Environmental Inc
www.CambridgeEnvironmental.com
