Creative Dedicated Experts

PCBs in Building Materials

State of the Science and Regulations / Practical Remediation(Real World Considerations)

Presented at Vermont Department of Environmental Conservation

November 2012

Agenda

Overview of the Issue (15 min) Why are we here?

Chemistry (20 min) Without chemicals, life itself would be impossible

Overview of human health risk (15 min) Why do we care?

Overview of the regulations (20 min)

What are the rules?

Practical assessment & remediation (35 min) What can we do about it?

2

PCBs: Real World Considerations

Overview of the Issue(Why are we here?)

3

4

Mug Shot

What has brought us all here today?

The resurrection!Victims of our own success

Durable, long lasting, high performance, and extremely useful compound that continues to haunt us

PCBs have a myriad of uses

Electrical devicesPaints, adhesivesPlasticizers Carbonless copy paper (think about

your document archives!)The stuff of epic Superfund sites and the headache of electrical utilities and old mills

Regulations came and major sources were thought to be under control, but….not exactly 5

PCBs detected in ancient sediments in U.K. laboratory (Alcock et al, 1994)

Lighting capacitors, paints, and “…desorption from the fabric of the building”

Presumably immobile compound found in polar bears

Certain Technical Paradoxes Have Been “Solved”

Global transport like grasshoppers Volatilize from soil in warm weather Deposition as temperatures cool Long distance atmospheric transport

Indoor air is a major atmospheric source of PCBs*

Soil volatilization not prime source

Steep urban/rural gradients

Indoor air is the source of outdoor air

Urban “Halo Effect” **

* Jamshidi et al. Concentrations and Chiral Signatures of Polychlorinated Biphenyls in Outdoor and Indoor Air and Soil in a Major U.K. Conurbation Vol. 41, No. 7 2007/Environmental Science and Technology. ** Diamond & Hodge. Urban Contaminant Dynamics: From Source to Effect. Vol. 41, No. 11, 2007/ Environmental Science & Technology

Urban – Rural Gradient

Higher Concentration Lower Concentration

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PCBs are like a Sci-Fi Super Villain with Global Reach

Coordinated air sampling

40 stations / seven continents

13 Persistent Organic Pollutants (POPS)

Kalahari Desert – One of the few remote sites where PCBs were not detected in air

The highest PCB air concentrations were detected in urban centers

7* Pozo, et al., Toward a Global Network for Persistent Organic Pollutants in Air: Results from the GAPS Study, Vol. 40, No. 16, 2006 / Environmental Science & Technology.

GAPS - Global Atmospheric Passive Sampling Study*

So if Urban Areas are the Hot Spots*….

…then the problem scope is huge!

Building stock – Over half of the concrete/masonry buildings in the U.S. were built between 1955 and 1975…peak PCB use timeframe

Herrick (2010) – “…one-third of the schools constructed from 1950 to 1970 will be found to contain PCBs…”

Can we have a quick show of hands?

* Diamond & Hodge. Urban Contaminant Dynamics: From Source to Effect. Vol. 41, No. 11, 2007/ Environmental Science & Technology 8

Importance of Building Age Category

1348 samples

10,000 ppm PCB

1,000 –10,000 ppm PCB

ND – 1,000 ppm PCB

*Source: Kohler et al, 2005 Environmental Science and Technology, 2005, 39, 1967-1973

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Back to the opening question: Why are we here today?

1992 – Realization: Building envelope PCBs impact indoor air Europe – Benthe et al, 1992, Johansson et al, 2001 U.S.A. – Leung 1996 - School indoor air/caulking association

1990s to 2000s – Awareness grows: PCB/Indoor air research blossomed Lots of Ph.D. theses were born Effects on indoor air became well documented (Vorhees 2001)

All before Herrick pronouncement of unrecognized sources in 2004 First project in Region 1 in late 1990s

2000s – Big U.S. projects hit the news Major PCB building materials remediation projects in EPA Region 1 European abatement well ahead of the U.S.

2000 to 2010 – Activism increases Grass roots – www.pcbinschools.org (school caulk sample 2004, website 2007) Contractor unions – 2003 Harvard School of Public Health collaboration Educators – 2010 Massachusetts Teachers Association/research collaboration

2009 and beyond – EPA issues limited guidance (initially focused on caulking) PCBs in Caulk in Older Buildings – September 30, 2009 Inaugurated a new research effort Enormous progress in research and in the publication of various guidance documents

1990

2000

2010

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Any questions before we move on?

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Without Chemicals, Life Itself Would Be Impossible

A Quick PCB Chemistry Lesson

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It pays to advertise….or is it an “un-wanted poster?”

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The Basics

Polychlorinated biphenyls

Poly prefix meaning “many”

Chlorine is an element

Biphenyl is the parent molecule

Translation - PCBs = biphenyl with many chlorines

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PCBs Marketed as Technical Mixtures (Aroclor is essentially a brand name)

Monsanto was only U.S. producer

1.4 billion pounds produced

>50 of 209 different congeners were used in the various Aroclor mixtures

Last 2 digits = amount of chlorine on a weight basis

Aroclor 1254 = 54% Chlorine by Mass Technical Mixture –

Think of it like 10W-40 Motor Oil. A chemical mixture composed to meet defined performance criteria.

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Let’s Add Some Definition

PCB Mixtures and Trade Names - With few exceptions, PCBs were manufactured as a mixture of various PCB congeners, through progressive chlorination of batches of biphenyl until a certain target percentage of chlorine by weight was achieved.

Aroclor - A PCB mixture produced from approximately 1930 to 1979. It is one of the most commonly known trade names for PCB mixtures. There are many types of Aroclors and each has a distinguishing suffix number that indicates the degree of chlorination.

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Let’s Add Some Definition (continued)

Congeners - PCBs are a class of chemical compounds in which 1–10 chlorine atoms are attached to the biphenyl molecule. A large number of chlorinated compounds are possible (209). The 209 possible compounds are called congeners.

Homologs - PCBs can also be categorized by degree of chlorination. The term “homolog” is used to refer to a group of PCB congeners with the same number of chlorines (e.g., trichlorobiphenyls). Congeners with different substitution patterns within a homolog group are referred to as isomers. For example, the dichlorophenyl homolog contains 12 isomers. All the PCB chemicals that have the same number of chlorine atoms are said to belong to the same homolog group. 

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PCBs Are Complex Chemical Mixtures (Actual Lab Gas Chromatogram)

Number Refers to Number of Chlorines in PCBSource: GC Chromatogram provided by Contest Labs, MA

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Composition of PCB Aroclor Mixtures(% Chlorine by Homolog Number)

0

10

20

30

40

50

60

1221

1242

1248

1254

1260

% C

HLO

RIN

E /H

OM

OLO

G

Aroclor

# Chlorines 1 2 3 4 5 6 7 8 9 10 # Congeners 3 12 24 42 46 42 24 12 3 1

Total = 209

For Aroclor by Aroclor congener plots, visit this EPA website: http://www.epa.gov/osw/hazard/tsd/pcbs/pubs/aroclorplots.pdf

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Until the regs change, or unless you apply for a project-specific change under Subpart Q of TSCA, Soxhlet Extraction is a must for solid samples in Region I.

Why should EPA change?1. It’s slow….18 hour extraction

2. It’s not green….it’s labor intensive and uses a lot of solvent (methylene chloride)3. Other methods (pressurized fluid extraction [3545A], microwave extraction [3546]) are

faster and just as efficient, rigorous, and robust

Laboratory Analyses (Extraction and Analysis)

Extraction

Waters 3510C (separatory funnel)

Solid 3540C (soxhlet)

Analysis

EPA SW-846 Method 8082A, (PCB Aroclors), 2007

EPA Method 680 (PCB Homologs), 1985

EPA Method 1668B (PCB Congeners), 2008

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Pros and Cons of the Analytical MethodsMethod Pro ConAroclors(8082A)

Relatively inexpensive (<$100 per sample)

Widely available analytical service

Affected by weathering Although still used, it is not the best

for air sampling

Homologs(680)

Provides a good estimate of total PCBs Overcomes weathering of Aroclors Good option for air analysis (Aroclors

may not evaporate as tech. mixtures) More accurate (not dependent on

human interpretation)

Expensive (~$300 per sample) A service not offered by all

laboratories

Congeners(1668B)

Provides a breakout of all the individual PCB chemicals present

Provides quantitation of the dioxin-like congeners

Provides added flexibility in a risk assessment. More accurate (not dependent on human interpretation)

Expensive (~$800 per sample) Few laboratories offer the analysis

(less than with homologs) Not all of the laboratories do it well

(engage your QC chemist)

Screening kits (various)

Cheap May help with faster delineation

Subject to interferences Generally higher detection limits No standing under the Compendium

of Analytical Methods (CAM) in Massachusetts (not applicable to VT).

Not an option for risk assessment

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Any questions before we move on?