1. A study of Polychlorinated Biphenyls in Deckerville Michigan
July 9, 2007

2. Background of Deckerville:
Location:
Sanilac County Michigan
662,000 acres of farmland
The thumb of Lake Huron
Approximately 100 Km north of Detroit
History:
1870 Charles Decker began a lumber business
1893 the village became a stop on the Pere Marquette Railroad

3. Background of PCBs:
On April 19th 1979 the EPA announced regulations banning the production of PCBs and gradually phasing out use of PCBs for many industrial uses. (1)
PCBs have been shown to have significant ecological and human health effects including cancer and developmental toxicity. (2)
“People who eat PCB-contaminated fish face an increased risk of cancer and other serious medical conditions including developmental, immune system, thyroid and reproductive problems.” (3)
PCB PCB PCB PCB 118

4. The Study:
Determining if the contaminants of interest are local source of contamination
Used raw data collected between May of 1992 through February of 1993
Used the Clausius-Claperyon Equation to determine the enthalpy of vaporization

5. PCB 8: 2,4’-dichlorobiphenyl

6. Data analysis To use the Clasusius-Clapeyron equation the
partial pressure in atmospheres,
calculated from the concentration in ng/m3 by the formula P=(Concentration/Molar Mass) *RT*(10-9),
Partial pressure was graphed verse the temperature.
The slope of that line was divided by the gas constant (R) in J*K-1*mol-1, which is the heat of vaporization.

8. The heat of vaporization for 2,4’-dichlorobiphenyl at Deckerville, MI
18.8 kJ mol-1.
This does not indicate a local source for this congener because it is less then 50 kJ mol-1.

9. Regression analysis Significance Not strong because
F is 1.06 x 10-8 which is less then 0.05
Not strong because
R value of 0.60 is less then 0.7.
A plot of the residuals agrees with the r value

10. The Henry’s Law Constant
atm m3 mol-1.

11. PCB Congener 28 Not extremely toxic.
In general toxicity increases with mass.
Increased toxicity because of structure.
Main concern is bioaccumulation in fish.

12. Results of Regression

13. Results continued…

14. Calculations Enthalpy of Vaporization: Henry's Law Constant
20.8 KJ mol-1
Henry's Law Constant
atm m3 mol-1
Water Solubility
0.27 mg/l
Henry's Law estimate of 298K (saturated)
2.1 x 10-7 atm
Average P = 1.1 x K

15. PCB Congener 52 One of the less toxic congeners of PCB
Shape
Number of chlorines
Was used heavily in the 50’s, 60’s and 70’s
Fire retardants
Hydraulic fluids
Pesticides
Determined to be carcinogenic
The manufacturing was discontinued in 76

16. Results of Regression

17. Results continued… Summary output data: R = 0.04610811
Well below the significant value of 0.07
R^2 identifies that approximately 78% of the variation is possibly coming from alternate sources
F (sig) = E-05
Very significant with a very high level of confidence

18. Residual
Residual plot shows that the model is appropriate for the data because no real pattern persists.
There could be some error when looking at the normality of the variation.
The low number of plotted points could have skewed the data

19. Enthalpy of Vaporization:
The calculated value
KJ mol^-1
The value is below the accepted value
Conclude that the Deckerville site does not have a local source of the congener 52
Henry’s Law= 2.0E-04 atm-m3/mol

25. BIBLIOGRAPHY
EPA Bans PCB Manufacture; Phases Out Uses. (accessed 7/5/07). EPA press release 4/19/1979.
PCBs: Cancer Dose-Response Assessment and Application to Environmental Mixtures. U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Washington Office, Washington, DC, EPA/600/P-96/001F, 1996.
EPA Proposes Comprehensive Plan to Clean Up Hudson River PCBs. (accessed 7/5/07). EPA press release 12/6/2000.