3. What Are PCBs?
Polychlorinated biphenyls Structure of Polychlorinated Biphenyl
22 11 1’
1’ 2’
2’
A group of man-made chemicals
209 combinations (congeners)
Different degradability 33 3’
3’
Toxicity varies
Different abundances
Very stable 44 55 5’
5’ 4’
4’
No known natural sources
Nearly everybody has traces in body
Commonly known to be used in electrical equipment, industrial
processes, and manufacturing
Banned from production in 1976
Nonpolar/hydrophobic
Do not easily dissolve in water
Binds strongly to sediment particles
Fat soluble and stored in an organism's fatty tissue
3
dep.state.ct.us/wst/pcb/pcbindex.htm www.trwnews.net/isdioxindangerous.htm www.epa.gov/pcb/
4. Synthesis
Commercial products mixtures
Aroclors most common in US
Various methods
Chlorinate biphenyl
Modified Suzuki coupling reaction
Bromo- or Iodobenzene Boronic Acid
4
Kania-Korwel I, Parkin S, Robertson LW, Lehmler HJ. “Synthesis of polychlorinated biphenyls and their metabolites with a modified Suzuki-
coupling.” Chemosphere. 2004 Aug;56(8):735-44
6. Brief History
1881: First Synthesis
1914: Measurable amount in bird feathers
1927: PCBs first manufactured in Alabama (Swann)
1930’s: First worker health problems & studies
1935: Monsanto bought Swann
1947: GE began using PCBs in electrical equipment
1950’s: Toxicity of PCBs of concern but not fully acted on
1960’s: Increasing awareness of PCB hazards
1968: 1300 Japanese residents ate rice contaminated with PCBs
1970’s: Increased study into PCBs toxicity
1970’s: Government gets involved
1979: EPA issues final regulations banning manufacture of PCBs
Late 1980’s: Companies cleanup and stop using PCBs
Early 90’s: EPA declares PCB carcinogens, endocrine disruptors, and
reproductive toxins
2000: United Nations Environment Program committee ban on PCBs
Adapted from: “Lake Michigan Mass Balance Study - PCB Modeling Report” Ronald Rossmann, Editor, EPA-600/R-04/167 December 2006
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8. Health Concerns
PCBs cause a variety of adverse health effects
Cancer
Animals
Immune system
Reproductive system www.trwnews.net/isdioxindangerous.htm
Nervous system
Endocrine system
emedicine.medscape.com/article/1093801-overview www.foxriverwatch.com/jointdisease.jpg
Affects children through PCB-exposed mothers
Physical and mental
The toxicity of PCBs varies considerably among congeners
Coplanar PCBs, non-ortho, generally are most toxic congeners
Health effects may be interrelated
Alterations in one system may have significant implications for the
other systems of the body
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9. Health Impact
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Image 1: www.atsdr.cdc.gov/sites/springvalley/exposure_pathways.gif Image 2: en.wikipedia.org/wiki/File:Health_effects_of_pollution.png
10. Regulations
EPA 40 CFR part 761 (§761)
Marking
Manufacture
Processing
Distribution
Use
Storage
Disposal
PCBs in caulking and sealant materials was never
authorized by EPA
Use is not authorized
Highly unlikely to be authorized
Caulk containing 50 ppm PCB must be removed
Testing “may be advisable” (EPA Nov. 2003)
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11. Media Coverage
Doherty High Worcester MA
2 incidents
Yorktown School District PCB Contamination
French Hill Elementary School
Ben Franklin Elementary School
New York City
Citywide concern
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14. Remediation Steps
1. Identify suspect PCB material
Physical inspection
Identify pre-1980 construction
Review of architecture plans
Review construction and remodeling history
2. Sample and Test
Suspect materials
Adjacent material
Air
Soil
3. Determine exposure level
How often people interact with material?
How could people interact with material?
4. Determine method to minimize exposure
Removal
Barrier
5. Disposal
Verify PCB material left is below allowable concentration
Unregulated waste
Regulated waste
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15. Harvard Study
July 2004 – HSPH Press Release
24 Buildings Tested
1/3 or 8 of 24 Exceeded 50 ppm
PCB
Up to 50,000 ppm PCB
Caulk Unrecognized and
Widespread Source of PCBs
Recommends Routine Testing of
Caulk
Robert F. Herrick, Michael D. McClean, John D. Meeker, Lisa K.
Baxter, George A. Weymouth. “An Unrecognized Source of PCB
Contamination in Schools and Other Buildings.” Environmental
Health Perspectives. 2004, 112 (10), 1051.
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17. UMASS Amherst Lederle Building
Project began as exterior
weatherization
13 story building
Contractor hired, pulled PCB
sample leading to initial
identification
Resulted in almost 2 year delay
on project
Change order for the contractor
$2 million
3 consultants involved
Work completed under self-
implementing remediation plan
some coverage of caulk joints due
to still high PCB
Soil removal required
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18. Bronx – Sept. 2009
A news investigation 17 months ago
revealed dangerous levels of potentially
cancer-causing PCBs in the window
caulking of schools across the city built
before the material was banned in 1977
City has yet to remove it
Lawsuit to require the city to
Test for PCB caulk in at-risk schools
Force the removal of all tainted material
PCB levels
2,000 times the legal limit of 50 parts per
million
Anything over 50 ppm is deemed toxic under
federal law
In response to The News' investigation
Education Department scrubbed the schools
Removed contaminated soil “We're starting another school
year, and the city still has done
Did not remove the toxic caulking nothing about this problem,”
City concluded that air tests showed low risk said Gonzalez, whose daughter
of exposure Emelina, 6, attends Public
Ongoing discussions with the EPA to School 178 in the Bronx.
develop a plan to address the issue
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19. Case Study – Overview
Project to demolish existing school buildings
Library
Attached building
A consultant tested for PCBs after project bid but prior to full
demolition
Mixed PCBs results
Extreme highs and lows
Tests showed almost all caulking on both buildings >50 ppm PCBs
North Elevation: Darling Library (left) and Baxter West Elevation: Baxter Building. 19
Building (right) showing connector.
20. Case Study – First Step
Fuss & O’Neill requested to assist with removal of caulking to
facilitate demolition
Buildings needed to be demolished before start of school
About 2 months
Contractor caulk samples needed further characterization
Possible cross contamination of samples
Caulk in both buildings was resampled
Proper decontamination was performed
Also sampled adjacent porous surfaces to determine PCB concentration
Results
Many areas contained no PCB caulking
Library had no PCB caulking
Allowed demolition
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21. Case Study – Removal
Bids received
Company selected to perform work
Work on exterior was performed on enclosed lifts
Control dust emissions
Materials adjacent to caulk cut or removed
Brick, concrete, and limestone
Whole sections for some structures
Disposed of as TSCA waste >50 ppm PCBs
Samples
Verification samples collected every 5 linear feet (§761 subpart O)
Four samples were composited to decrease analysis cost
Several locations failed initial verification sampling
Additional removal of adjacent substrates was performed
Contractor tried using cleaning product Capsur® to wash
surfaces where cutting had occurred
Used due to extreme depths into substrate not observed in initial
sampling
Resulted in passing verification samples
Did not require further cutting into substrates in most locations
Next slide shows some of the locations after removal
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23. Case Study – Results
Soil adjacent to buildings also had elevated PCB content and
was removed.
All waste disposed as TSCA regulated waste containing >50
ppm PCBs as required under a performance based removal
project.
Demolition schedule was essentially maintained and buildings
were demolished.
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24. Caulk
Caulk is a suspected PCB-containing material and
should be routinely tested for PCBs prior to
disturbance.
Caulk is a significant PCB exposure risk.
PCB-containing caulk must be removed and disposed
of as PCB waste upon discovery.
State agencies and private businesses have begun to
develop guidelines for testing and removal of PCB-
containing caulk.
Currently testing caulk for PCBs is not required by
law but “may be advisable.”
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25. Project Implementation
Each project is site specific
Concentration levels
Materials present
History of the building.
Which plan depends on
Time
Budget
Logistics
Area occupied?
Time for completion is weeks to months to years
Although not required to test, addressing the problem
internally can avoid bad public relations.
Once one contaminated area is remediated, other areas should
be considered.
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