Development of a Raoult’s Law-Based Screening-Level Risk Assessment Methodology for Coal Tar and Its Application to Ten Tars Obtained from Former Manufactured Gas Plants in the Eastern United States


A Raoult’s law-based screening-level assessment methodology was developed to calculate the carcinogenic and non-carcinogenic risks from ingestion of coal tar-contaminated water and it was applied to ten coal tars obtained from sites in the eastern United States. This approach provides a simple risk screening based on the conservative assumptions of Tier 1 in both the ASTM RBCA methodology and the USEPA Soil Screening Guidance. Results across the ten tars exhibited similar patterns, even though the coal tars had significantly different chemical compositions, and in all cases the screening-level risks were above the USEPA thresholds. There was no appreciable difference in the total risks when using either the current USEPA 1993 PAH risk assessment guidance or the proposed 2010 guidance. Benzene, while present at low concentrations within the coal tars, posed the dominant risk and strong correlations were observed with the benzene mole fraction.

Share and Cite:

D. Brown, "Development of a Raoult’s Law-Based Screening-Level Risk Assessment Methodology for Coal Tar and Its Application to Ten Tars Obtained from Former Manufactured Gas Plants in the Eastern United States," Journal of Environmental Protection, Vol. 4 No. 6A, 2013, pp. 1-11. doi: 10.4236/jep.2013.46A001.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] USEPA, “US Production of Manufactured Gases: Assessment of Past Disposal Practices,” EPA/600/S2-88/012, 1988.
[2] A. W. Hatheway, “Manufactured Gas Plants: Yesterday’s Pride, Today’s Liability,” Civil Engineering, Vol. 67, No. 11, 1997, pp. 38-41.
[3] T. D. Hayes, D. G. Linz, D. V. Nakles and A. P. Leuschner, “Manufactured Gas Plant Sites,” Amherst Scientific Publishers, Amherst, 1996.
[4] E. O. Rhodes, “The History of Coal Tar and Light Oil,” In: A. J. Hoiberg, Ed., Bituminous Materials: Asphalts, Tars and Pitches, Interscience Publishers (John Wiley & Sons), New York, 1966.
[5] R. Eng, “Survey of Town-Gas and Byproduct Production and Locations in the US (1880-1950),” EPA/600/7-85/004, 1985.
[6] M. Krasley, “Coal Tar Contamination of the Environment by the Manufactured Gas Industry. A Review,” FL 354.551, 1990.
[7] C. J. Castaneda, “Invisible Fuel: Manufactured and Natural Gas in America, 1800-2000,” Twayne Publishers, New York, 1999.
[8] C. A. Peters and R. G. Luthy, “Coal Tar Dissolution in Water-Miscible Solvents: Experimental Evaluation,” Environmental Science & Technology, Vol. 27, No. 13, 1993, pp. 1831-2843. doi:10.1021/es00049a025
[9] M. Zander, “Aspects of Coal Tar Chemistry. A Review,” Polycyclic Aromatic Compounds, Vol. 7, 1995, pp. 209-221. doi:10.1080/10406639508009625
[10] M. Zander and G. Collin, “A Review of the Significance of Polycyclic Aromatic Chemistry for Pitch Science,” Fuel, Vol. 72, No. 9, 1993, pp. 1281-1285. doi:10.1016/0016-2361(93)90126-M
[11] D. G. Brown, L. Gupta, H. K. Moo-Young and A. Coleman, “Raoult’s Law-Based Method for Determination of Coal Tar Average Molecular Weight,” Environmental Toxicology and Chemistry, Vol. 28, No. 4, 2005, pp. 1886-1892. doi:10.1897/04-470R.1
[12] EPRI, “Chemical and Physical Characteristics of Tar Samples from Selected Manufactured Gas Plant (MGP) Sites,” TR-102184, 1993.
[13] D. G. Brown, C. D. Knightes and C. A. Peters, “Risk Assessment for Polycyclic Aromatic Hydrocarbon NAPLs Using Component Fractions,” Environmental Science & Technology, Vol. 33, No. 24, 1999, pp. 4357-4363. doi:10.1021/es9902423
[14] D. Mackay, W. Y. Shiu and K. C. Ma, “Illustrated Handbook of Physical-Chemical Properties and Environmental Fate for Organic Chemicals,” Lewis Publishers, Boca Raton, 1992.
[15] C. A. Peters, C. D. Knightes and D. G. Brown, “Long-Term Compositional Dynamics of PAH-Containing NAPLs and Implications for Risk Assessment,” Environmental Science & Technology, Vol. 33, No. 24, 1999, pp. 4499-4507. doi:10.1021/es981203e
[16] USEPA, “A Resource for MGP Site Characterization and Remediation,” EPA 542-R-00-005, 2000.
[17] R. G. Luthy, D. A. Dzombak, C. A. Peters, S. B. Roy, A. Ramaswami, D. V. Nakles and B. R. Nott, “Remediating Tar-Contaminated Soils at Manufactured Gas Plant Sites: Technological Challenges,” Environmental Science & Technology, Vol. 28, No. 6, 1994, pp. 266A-276A. doi:10.1021/es00055a002
[18] NIEHS, “The 8th Report on Carcinogens: 1998 Summary,” 1998.
[19] USEPA, “Provisional Guidance for Quantitative Risk Assessment of Polycyclic Aromatic Hydrocarbons,” EPA/ 600/R-93/089, 1993.
[20] USEPA, “Integrated Risk Information System,” 2011.
[21] D. W. Gaylor, S. J. Culp, L. S. Goldstein and F. A. Beland, “Cancer Risk Estimation for Mixtures of Coal Tars and Benzo(A)Pyrene,” Risk Analysis, Vol. 20, No. 1, 2000, pp. 81-86. doi:10.1111/0272-4332.00008
[22] J. G. Bolten, P. F. Morrison, S. A. Resetar and K. A. Wolf, “Health Risk from a Coal Tar Disposal Site,” 1988.
[23] National Research Council, “Risk Assessment in the Federal Government: Managing the Process,” National Academy Press, Washington DC, 1983.
[24] ASTM, “Standard Guide for Risk-Based Corrective Action Applied at Petroleum Release Sites,” E1739-95, 1995.
[25] ASTM, “Standard Guide for Risk-Based Corrective Action,” E2081-00, 2000.
[26] USEPA, “Soil Screening Guidance: User’s Guide,” EPA/ 540/R-96/018, 1996.
[27] USEPA, “Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites,” OSWER 9355.4-24, 2002.
[28] C. Eberhardt and P. Grathwohl, “Time Scales of Organic Contaminant Dissolution from Coplex Source Zones: Coal Tar Pools vs. Blobs,” Journal of Contaminant Hydrology, Vol. 59, No. 1-2, 2002, pp. 45-66. doi:10.1016/S0169-7722(02)00075-X
[29] M. F. Khalil, U. Ghosh and J. P. Kreitinger, “Role of Weathered Coal Tar Pitch in the Partitioning of Polycyclic Aromatic Hydrocarbons in Manufactured Gas Plant Site Sediments,” Environmental Science & Technology, Vol. 40, No. 18, 2006, pp. 5681-5687. doi:10.1021/es0607032
[30] L. Liu, S. Endo, C. Eberhardt, P. Grathwohl and T. C. Schmidt, “Partition Behavior of Polycyclic Aromatic Hydrocarbons between Aged Coal Tar and Water,” Environmental Toxicology and Chemistry, Vol. 28, No. 8, 2009, pp. 1578-1584. doi:10.1897/08-276.1
[31] USEPA, “SAB Review of EPA’s ‘Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures (February 2010 Draft)’,” 2011.
[32] H. Moo-Young and D. Brown, “Laboratory Assessment of Leaching Potential of Coal Tar at MGP Sites,” 1009425, 2004.
[33] USEPA, “Risk Assessment Guidance for Superfund. Volume 1. Human Health Evaluation Manual (Part A),” EPA/540/1-89/002, 1989.
[34] USEPA, “Guidelines for Exposure Assessment,” EPA/ 600/Z-92/001, 1992.
[35] USEPA, “Risk Assessment Guidance for Superfund. Volume 1. Human Health Evaluation Manual. Supplemental Guidance—Standard Default Exposure Factors. Interim Final Report,” OSWER Directive 9285.6-03, 1991.
[36] USEPA, “Role of the Baseline Risk Assessment in Superfund Remedy Selection Decisions,” OSWER Directive 9285.6-03, 1991.
[37] USEPA, “Guidelines for Carcinogen Risk Assessment,” EPA/630/P-03/001B, 2005.
[38] M. Fraser, J. F. Barker, B. Butler, F. Blaine, S. Joseph and C. Cooke, “Natural Attenuation of a Plume from an Emplaced Coal Tar Creosote Source over 14 Years,” Journal of Contaminant Hydrology, Vol. 100, No. 3-4, 2008, pp. 101-115. doi:10.1016/j.jconhyd.2008.06.001
[39] USEPA, “Guidelines for the Health Risk Assessment of Chemical Mixtures,” EPA/630/R-98/002, 1986.

Copyright © 2021 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.