PCBs in Construction : Update
for an Emerging Issue
David O. Carpenter, MD
University at Albany
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meta ortho
2'
3'
para
4'
meta ortho 6'
5'
Polychlorinated Biphenyl
PCBs: A mixture of 209 congeners used in indoor caulk, fluorescent
light ballasts, paints, floor sealants, capacitors and transformers.
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Characteristics of PCBs
• Lipophilic substances used for electrical insulation
and as a solvent.
• Relatively non-flammable.
• Volatility and water solubility decrease as number
of chlorines increase.
• Persistence in the environment and in the human
body increase with numbers of chlorines.
• Most health studies measure PCBs in the blood.
But this reflects primarily only the concentrations
of the more persistent PCBs.
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Health Effects of Exposure to PCBs
• Cancer: PCBs are known human
carcinogens.
• Immune suppression: More frequent and
more serious infections.
• Endocrine effects: Estrogen mimics.
• Nervous system effects: Reduce IQ and
memory. Especially bad in schools.
• Diabetes: Increases risk.
• Heart Disease: Elevates lipids and raises
blood pressure.
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Routes of Exposure to PCBs
• Traditionally most exposure to PCBs has
been assumed to be by ingestion, especially
of animal fats. The PCBs congeners in
animal fats tend to be higher chlorinated and
more persistent.
• PCBs in air are primarily lower chlorinated
and less persistent. If PCBs are in
construction materials they will volatize.
• The question is whether these air borne
PCBs cause disease.
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Table 1. Physical characteristics of PCBs by homologue groups at 25º
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Aroclor 1260 liquid
% of Total PCB
12
10
8
6
4
2
0
PCB congener in elution order
% of Total PCB
Aroclor 1260 vapor
10
8
6
4
2
0
PCB congener in elution order
Figure 2. The congener patterns in Aroclor 1260 liquid (top) and the congener pattern seen when
passing air over the liquid and collecting and analyzing the vapor-phase PCBs
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Table 2. Half-life of single PCB congeners in the human adult body
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Our Studies
• We have performed two types of studies.
• The first uses the NYS SPARCS dataset which
gives disease diagnosis upon discharge from
hospitals. This has large numbers, but no individual
exposure assessment beyond the zip code of
residence near to waste sites. These are ecologic,
hypothesis-generating studies. Exposure is
assumed to be primarily by inhalation.
• The second type of study is of a smaller population
with direct measures of exposure and with personal
medical and clinical chemistry history.
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Health Data:
1.
The NYSDOH SPARCS
records all diseases (up to
15) identified in every
hospital inpatient by ICD-9.
The publically available
dataset also provides age,
gender, race, zip code of
residence and method of
payment of hospital charges.
We have this data for the
years 1993-2008, with
approximately 2.5 million
entries per year.
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SES and Behavioral Data
Derived from Two
Sources:
1. Average family income
was obtained by zip code
from the 1990 and 2000
US census.
2. Behavioral data, currently
available only at a county
level, was obtained from
the Behavioral Risk Factor
Surveillance System of
CDC and NYSDOH.
Zip Codes Grouped by Exposure Status
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POPs and Diabetes
• Diabetes has usually been thought to be a
lifestyle disease resulting from poor diet,
obesity and lack of exercise.
• While lifestyle is important, it may not be
the most important risk factor for
developing diabetes.
• New evidence shows that people with high
concentrations of several POPs are more
likely to have diabetes.
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Crude (unadjusted) hospitalization rates for diabetes before modeling for
all of the NYS population (except NYC) for ages 25-74 years in clean,
other and POP sites (A) and broken down by age (B). The numbers
above the bars indicate the rates per 100,000.
* - statistically significant compared to “clean” sites ( p<.05 ).
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Results of Regression Analysis for Adult Diabetes Discharge
Coeffici
ent
SE
RR (CI)
Clean Site (ref)
0.000
1.00
1.00
POPs Site
0.208
1.04
1.23 (1.15-1.32)
<.0001
Other Waste Site
0.222
1.04
1.25 (1.16-1.34)
<.0001
Hudson River
0.311
1.04
1.36 (1.26-1.47
<.0001
SE= standard error; RR = rate ratio; CI = 95% confidence interval.
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P-Value
Population Characteristics - Site History
• Akwesasne Mohawk Nation:
• A Native American community of nearly 10,000 people.
• Comprises approximately 28,000 acres in New York, Ontario, and Quebec.
• Home for many generations of Mohawk people; community members place special
value on the environment and engage in subsistence activities (fishing, hunting).
• Industrial sites:
– General Motors - Central Foundry
Division (GM-CFD). A US Federal
Superfund Site in 1983.
– ALCOA
New York State Superfund Site.
Upstream from the GM plant.
– Reynolds Metals, Inc.
New York State Superfund Site.
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3
Diabetes at Akwesasne
• We studied 601 Mohawks ages 18-84 years,
obtaining fasting glucose, history of diagnosis of
diabetes, serum PCBs and 3 pesticides (DDE,
HCB, mirex).
• The prevalence of diabetes was 18.5%.
• After adjustment for sex, age, BMI, and smoking,
the risk ratio (RR) for having diabetes,
comparing the highest to lowest quartile was
2.21 for total PCBs and 3.75 for total pesticides.
Both results were statistically significant.
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Which PCBs and Which Pesticides
are Most Associated?
• We performed two types of adjustment in an
effort to see which PCB congeners or which
pesticides were responsible.
• First we adjusted the PCB results for total
pesticides, and the pesticide results for total
PCBs. The RRs for both were reduced
somewhat.
• Then we adjusted results for different groups
of PCBs and the three individual pesticides
for all other contaminants.
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Association Between Diabetes and Various
POPs after Adjustment for all other POPs
and Number of Chlorines.
• Exposure
RR
p-trend
•
•
•
•
•
•
5.02
0.40
1.27
1.74
2.18
1.75
0.034
0.404
0.300
0.003
0.206
0.518
Tri-Tetra
Penta-Hexa
Hepta Plus
HCB
DDE
Mirex
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The Significance of These Results
• These results show that the major
association is which the PCBs that have
only 3 or 4 chlorines. These are the more
volatile and less persistent congeners.
• Of the pesticides only HCB showed a
significant association and it was much
less that the low chlorinated PCBs.
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Do These Effects Results From
Dioxin-like PCBs?
• Some PCBs activate the AhR, the dioxin
receptor, but most do not. Many adverse
health effects are known to result from dioxinlike activity.
• We analyzed results based for PCBs with no
or only one ortho chlorine, since PCBs with
dioxin-like activity have no more than one
ortho chlorine.
• We then distinguished associations of dioxinlike and non-dioxin-like PCBs.
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RRs of PCB Congeners Having No or One
Ortho-substituted Chlorine After
Adjustment for all Other POPs.
RR
• All non-mono 5.25
• Dioxin-like
0.91
• Non-dioxin-like 7.54
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p-trend
0.0002
0.2174
0.0185
Significance of these Results
• We have found that different PCB congeners and
different chlorinated pesticides have different
associations with these diseases.
• For diabetes the PCB congeners showing strong
associations are those with few chlorines lacking
dioxin-like activity, and these are the ones that are
more volatile.
• Inhalation is the likely the most important route of
exposure leading to development of diabetes.
• Those who study total PCBs or total pesticides likely
miss important associations.
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The Tragic Story of JM and GM
• JM was employed as a chemist at a
company that dealt with old oils from
transformers. He was told to smell the oils
to see if they contained PCBs. This he did
from 1994 until 2003. In 2003 he was
found to have thyroid cancer. In 2011 he
was diagnosed with malignant melanoma.
In 2012 he was diagnosed with lung
cancer. He died in 2013.
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The Tragic Story of JM and GM
(continued)
• GM, wife of JM, was employed as a dish
washer and person responsible for
dumping used oils. She was told to smell
the oils to determine whether they
contained PCBs.
• GM was diagnosed with thyroid cancer in
2003. In 2011 she was diagnosed with a
severely dysplastic nevus, a precursor to
malignant melanoma.
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Table 3. PCB concentrations (µg/kg or ppb wet weight) in serum samples
from JM and GM (nd = not detected)
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PCB concentrations (µg/kg or ppb wet weight) in serum
samples from JM and GM (nd = not detected) in relation to
those from the National Health and Nutrition Examination
Survey random sample of US residents.
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Inhaled PCBs Caused These
Cancers
• For two individuals who are not blood
relatives to develop the same cancers
cannot be due to chance.
• The PCB content in their blood indicates
large exposure to volatile PCBs.
• This is very strong evidence that inhaled
PCBs caused JM and GM’s cancers.
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Conclusions
• These results strongly suggest that
inhalation of PCBs can cause diabetes
and cancer.
• PCBs don’t have to be persistent in order
to cause disease.
• PCBs in the air, whether indoor or outdoor,
pose serious risks of human disease via
inhalation.
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Questions?
David O. Carpenter, MD
dcarpenter@albany.edu
518-525-2660
www.albany.edu/ihe
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