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PCBs in Construction : Update for an Emerging Issue

David O. Carpenter, MDUniversity at Albany

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P c Boly hlorinated iphenylPCBs: 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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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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PCB congener in elution order

PCB congener in elution order

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Aroclor 1260 liquid

Aroclor 1260 vapor

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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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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.

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.

Health Data:SES and Behavioral Data Derived from Two Sources:

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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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Coefficient

SE RR (CI) P-Value

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

Clean Site (ref) 0.000 1.00 1.00

SE= standard error; RR = rate ratio; CI = 95% confidence interval.

Results of Regression Analysis for Adult Diabetes Discharge

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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.

– ALCOANew York State Superfund Site.Upstream from the GM plant.

– Reynolds Metals, Inc.New York State Superfund Site.

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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• Tri-Tetra 5.02 0.034• Penta-Hexa 0.40 0.404• Hepta Plus 1.27 0.300• HCB 1.74 0.003• DDE 2.18 0.206• Mirex 1.75 0.518

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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 dioxin-like 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 dioxin-like 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 p-trend

• All non-mono5.25 0.0002• Dioxin-like 0.91 0.2174• Non-dioxin-like 7.54 0.0185

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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, MDdcarpenter@albany.edu

518-525-2660www.albany.edu/ihe

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