Charles R. Wilkes, Ph.D., P.E.

E-mail: c.wilkes@wilkestech.com

EDUCATION

Carnegie Mellon University, Pittsburgh, PA
Ph.D., Civil Engineering, May 1994
Advisor: Mitchell J. Small


Research Abstract: My research consisted of developing an indoor air quality and human inhalation exposure model, MAVRIQ (Model for the Analysis of Volatiles and Residential Indoor-Air Quality). The primary goal was to investigate human inhalation exposures to volatile organic compounds (VOCs) resulting from a contaminated domestic water supply. Inhalation exposures to VOCs were estimated by considering human activity patterns, breathing rates, water uses, chemical properties, and other significant factors. The assessment of human inhalation exposure involved the implementation of both database sampling strategies and stochastic simulation of behavioral patterns based on survey results. Monte-Carlo type simulations were conducted to evaluate and quantify the effects of various behavioral and environmental factors on human inhalation exposure. This work was funded by the EPA.

C
arnegie Mellon University, Pittsburgh, PA
Master of Science received, Civil Engineering, May 1990

University of Wisconsin-Madison, Madison, WI
Bachelor of Science, Civil and Environmental Engineering, August 1985

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PROFESSIONAL EXPERIENCE

1997 to Present President, Research Director. Wilkes Technologies., Bethesda, MD
Modeling and analysis of environmental systems, specializing in indoor air quality and human exposure assessment.
2003 to Present

Principal, Program Manager, Senior Investigator. Building Sciences and Engineering Associates, Bethesda, MD
Manage and implement studies of moisture, mold growth, insulation fiber dispersion, soil-vapor intrusion, lead-in-drinking water, odor complaints, and other building-related environmental problems.  Studies include investigations, technical analyses, and remedial designs.  Review includes considering design aspects, building envelope issues, mechanical equipment, occupancy related factors and other issues influencing the quality of the environment and the function of the building.

1994 to1997 Research Scientist. GEOMET Technologies, Inc., Germantown, MD
Duties included conducting research in indoor air quality and human exposure assessment. Projects include evaluating and using existing models, and developing both statistical and deterministic models.
1989 Staff Engineer. Almes and Associates, Inc., Consulting Engineers, Pittsburgh, PA
Duties included sanitary landfill designs, leachate collection systems, sanitary sewer pipeline designs, stormwater management designs, soil erosion and sediment control plans, Pennsylvania Department of Environmental Resources  (DER) earth disturbance permits, and Pennsylvania DER stream encroachment permits.
1987 to 1989 Staff Engineer. Pedersen and Pedersen, Inc., Consulting and Environmental Engineering Services, Mars, PA
Duties included sanitary landfill designs, stormwater management designs, soil erosion and sediment control plans.
1986 to 1987

 

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Staff Engineer. Meixner Engineers and Surveyors, Inc., Collegeville, PA
Duties included storm water management designs, soil erosion and sediment control plans, survey crew chief, subdivision site designs, road design, and sanitary sewer pipeline design.

 

PROFESSIONAL ACCOMPLISHMENTS

Current work includes the continuing development of the Total Exposure Model (TEM), a comprehensive exposure model assessing human exposure and dose to indoor pollutants in multi-zone indoor environments using finite difference numerical techniques combined with stochastic representation of human behavior and other model inputs. Numerous human activity and other population-based data resources are incorporated. Exposures via the principal routes, inhalation, ingestion and dermal, are modeled and subsequently used as inputs for a pharmacokinetic model used to predict blood and target tissue doses. I have developed and implemented interfaces between TEM and the Exposure Related Dose Estimation Model (ERDEM) and other PBPK models.

 

Current projects specifically focus on exposure to water-borne pollutants. TEM is being further developed and utilized under funding from the US. EPA Human Exposure Research Branch (Las Vegas) and the National Center for Environmental Assessment (Cincinnati), focusing on exposure to disinfection byproducts (DBPs) brought into the indoor environment via the water supply.

 

Residential water use behaviors presented in the NHAPS, REUWS, RECS and CSFII databases have been extensively analyzed to derive typical indoor water-use characteristics for various U.S. subpopulations for use as TEM model input parameters.

 

Currently, a combination field and modeling project is being conducted to examine the link between exposure to DBPs and birth defects. This is a cooperative project involving the American Water Works Association Research Foundation (AWWARF), the Centers for Disease Control and Prevention (CDCP), and the US EPA (NHEERL, NRMRL, and NERL).has been applied to a study under the International Life Sciences Institute (ILSI) modeling exposure to trichloroethylene (TCE), dichloroacetic acid (DCA) and trichloroacetic acid (TCA).

 

Developed the precursor to TEM called the TCE Inhalation Exposure Model, for the US Air Force, which also modeled exposure to water-borne contaminants in multi-zone indoor environments. The TCE Inhalation Exposure Model expanded the capabilities and added a user-friendly interface to MAVRIQ (see Ph.D. research abstract).

 

Served on a technical committee for the International Life Sciences Institute (ILSI), an EPA sponsored working group chartered with examining techniques for estimating dermal and inhalation exposures to contaminants in drinking water. Conducting extensive case studies to demonstrate techniques for estimation of distribution of inhalation and dermal exposures to exposed populations. This work required modification of MAVRIQ to model volatilization and aerosol dispersion of three water-borne compounds (chloroform, methylparathion, chromium) from household water uses including showers, baths, toilets, faucets, dishwashers and clothes washers. Added inhalation and dermal uptake modules to estimate absorbed dose. The working group compiled a document that was published as a book and makes recommendations regarding future areas of research.

 

Completed work for USEPA Office of Pesticide Programs (OPP) and Office of Pollution Prevention and Toxics (OPPT) that involved the development of the windows-based version of the Multi-chamber Concentration and Exposure Model (MCCEM). MCCEM models emissions, transport, and decay of chemicals from various household consumer products. MCCEM also estimates associated inhalation exposures and calculates various exposure indexes for use in relation to lifetime cancer risks. Also developed the inhalation exposure component of the Consumer Occupational Model (COM), a finite difference implementation of a two-compartment indoor air quality/exposure model. Also participated in the development of the Wall Paint Exposure Model (WPEM), a tool designed for use by paint industry for estimating exposure due to painting events.

 

Other work included several exposure/risk modeling assessment projects. Conducted modeling study of radon and radon daughters introduced into home by water supply, and assessment of potential inhalation dose to residents. Developed statistical models to represent gas usage patterns for the Gas Research Institute (GRI). Developed model to represent carbon monoxide emissions from gas combustion appliances (GRI). Conducted research into the formation, migration, and resulting concentrations of nitrogen oxides and carbon monoxide due to combustion of natural gas in the home. Also, analyzed VOC emissions from interior paints while drying and participated in the design of studies for further characterizing emissions. Evaluated alternative models for representing the rate at which formaldehyde is emitted from urea-formaldehyde resins commonly used in composite wood building components such as particleboard, and sorption to reversible and irreversible sinks such as carpet and painted gypsum wallboard.

 

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SELECTED PUBLICATIONS
 

Wilkes CR, Hern SC and AD Mason. 2005. “Probability distributions for showering and bathing water-use behavior for various U.S. subpopulations.” Risk Analysis. 25(2):317-337

 

Wilkes CR, Kedderis GL, Mason AD, Niang LL, and JC Lipscomb. June 2006. USEPA.  Exposures and internal doses of trihalomethanes in humans: multi-route contributions from drinking water. Office of Research and Development,
National Center for Environmental Assessment, Cincinnati, OH. EPA 600/R-06/087. 
 

 

Wilkes CR, Hern SC, Mason AD, Niang LL, and KL Jensen. 2005. Quantification of exposure-related water uses for various U.S. subpopulations. USEPA Exposure and Dose Research Branch. EPA/600/R-06/003.

 

Ashley DL, Blount BC, Singer PC, Depaz E, Wilkes C, Gordon S, Lyu C, and Masters J. 2005. “Changes in blood trihalomethane concentrations resulting from differences in water quality and water use activities.” Archives of Environmental and Occupational Health. Vol. 60. No. 1. p7-15.

 

Wilkes CR, Nuckols JR, and MD Koontz. March 2004. “Evaluating alternative data gathering methods for the 1999 disinfection by-product field study.” American Water Works Association Research Foundation. Project #2831, Web Report, url: http://www.awwarf.org/research/TopicsandProjects/execSum/PDFReports/2831.pdf.

 

Wilkes CR, Power FW, Blancato JN, Hern SC, Mason AD, Tsang AM, et al. Sept. 2002. “Developing Individual Human Exposure Estimates for Individual DBPs.” Published as Appendix to The feasibility of performing cumulative risk assessments for mixtures of disinfection by-products in drinking water. Teuschler LK, Rice GE and JC Lipscomb. June 2003. USEPA National Center for Environmental Assessment. EPA/600/R-03/051.

 

Wilkes CR, Hern SC, Blancato JN, Mason AD, and LL Niang. June 2002. “Analysis of household water-use behavior for use as IAQ model parameters.” Proceedings: The Ninth International Conference on Indoor Air Quality and Climate. Monterey, California, USA.

 

Wilkes CR, Blancato JN, Hern SC, Power FW, and SS Olin. June 2002. “Integrated probabilistic and deterministic modeling techniques in estimating exposure to water-borne contaminants: Part 1: Exposure modeling.” Proceedings: The Ninth International Conference on Indoor Air Quality and Climate. Monterey, California, USA.

 

Wilkes CR and NJ Giardino. 1999. “A community comparison of exposures and risks from TCE in a contaminated groundwater supply vs. DBPs in a municipal water supply; Part I: Exposure assessment.” Proceedings: The Eighth International Conference on Indoor Air Quality and Climate. Edinburgh, Scotland. August 8 - 13, 1999. Vol. 2. p800- 805.

 

Wilkes CR. 1998. Chapter Seven “Case Study” and portions of Chapter Four “Developing exposure estimates.” Exposure to contaminants in drinking water: Estimating uptake through the skin and by inhalation, prepared by International Life Sciences Institute (ILSI) working group. CRC Press. p. 184-224.

 

Wilkes CR, Small MJ, Davidson CI, and Andelman JB. 1996. “Modeling the effects of water usage and cobehavior on inhalation exposures to contaminants volatilized from household water.” Journal of Exposure Analysis and Environmental Epidemiology, 6(4):393-412.

 

Wilkes CR, Koontz MD, and Billick IH. September 1996. “Analysis of various sampling strategies for estimating weekly average indoor NO2 concentrations in residences with gas ranges.” Journal of the Air & Waste Management Association, 46:853-860.

 

Wilkes C, Koontz M, Ryan M, and Cinalli C. “Estimation of emission profiles for interior latex paint.” Proceedings: The Seventh International Conference on Indoor Air Quality and Climate. Nagoya, Japan, July 21 ‑ 26, 1996. Vol. 2, p55-60.

 

Wilkes C., Modeling human inhalation exposure to VOCs due to volatilization from a contaminated water supply, Ph.D. Dissertation, Department of Civil Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, April, 1994.

 

Wilkes CR, Small MJ, Davidson CI, Andelman JB, and Pandian MD. “A human activity-indoor air quality model for predicting inhalation exposures to VOCs.” Proceedings: The Sixth International Conference on Indoor Air Quality and Climate. Helsinki, Finland. July 4 ‑ 8, 1993. Vol. 3, p409-414.

 

Wilkes CR, Small MJ, Andelman JB, Giardino NJ, and Marshall J. August 1992. “Inhalation exposure model for volatile chemicals from indoor uses of water.” Atmospheric Environment, 26A(12):2227-2236.

 

Wilkes CR, Small MJ, Andelman JB, Giardino NJ, and Marshall J. “Air quality model for volatile constituents from indoor uses of water.” Proceedings: The Fifth International Conference on Indoor Air Quality and Climate. Toronto, Canada. July 29 - August 3, 1990. Vol. 2, p 783-788.

 

Wilkes CR. May 1990. MAVRIQ: Model for the Analysis of Volatiles and Residential Indoor-Air Quality. Master's Thesis. Department of Civil Engineering. Carnegie Mellon University. Pittsburgh, PA.

 

Blancato JN, Power FW, Wilkes CR, Tsang AM, Hern SC, and SS Olin. June 2002. “Integrated probabilistic and deterministic modeling techniques in estimating exposure to water-borne contaminants: Part 2: Pharmacokinetic modeling.” Proceedings: The Ninth International Conference on Indoor Air Quality and Climate. Monterey, California, USA.

 

Lynberg, M,  Nuckols, JR, Langlois, P, Ashley, D, Singer, P, Mendola, P, Wilkes, C, Krapfl, H, Miles, E, Speight, V, Lin, B, Small, L, Miles, A, Bonin, M, Zeitz, P, Tadkod, A, Henry, J, and Forrester, MB. June 2001. “Assessing exposure to disinfection byproducts in women of reproductive age living in Corpus Christi, Texas, and Cobb County, Georgia: Descriptive results and methods” Environmental Health Perspectives. 109(6):597-604.

 

Giardino NJ and CR Wilkes. “A community comparison of exposures and risks from TCE in a contaminated groundwater supply vs. DBPs in a municipal water supply; Part II: Risk assessment.” Proceedings: The Eighth International Conference on Indoor Air Quality and Climate. Edinburgh, Scotland. August 8 - 13, 1999. Vol. 2. p818-823.

 

Giardino NJ, Gumerman E, Esmen NA, Andelman JB, Wilkes CR, Davidson CI, and Small MJ. 1992. “Shower volatilization exposures in homes using tap water contaminated with trichloroethylene.” Journal of Exposure Analysis and Environmental Epidemiology, Suppl. 1, p 147-158.

 

Small MJ, Wilkes CR, Andelman JB, Giardino NJ, and Marshall J. “Inhalation exposure from contaminated water uses: A behavioral model for people and pollutants.” Proceedings of the ASCE 1990 Specialty Conference on Environmental Engineering. Arlington, Virginia. July 8-11, 1990. p 764-771.

 

Giardino NJ, Gumerman E, Esmen NA, Andelman JB, Wilkes CR, and Small MJ. July 29, 1990 “Real-time air measurements of trichloroethylene in domestic bathrooms using contaminated water.” Proceedings, The Fifth International Conference on Indoor Air Quality and Climate. Toronto, Canada.. Vol. 2, p 707-712.

 

Andelman JB, Giardino NJ, Marshall J, Esmen NA, Borrazzo JE, Davidson CI, Small M, and Wilkes C. “Exposure to volatile chemicals from indoor water uses.” Proceedings: The EPA/A&WMA Specialty Conference: Total Exposure Assessment Methodology. Las Vegas, Nevada. November 27 – 30, 1989. p 300-311.

 

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SELECTED CONFERENCES AND SEMINARS

 

U.S. EPA International Workshop on Optimizing the Design and Interpretation of Epidemiological Studies to Consider Alternative Disinfectants of Drinking Water. July 2-3, 2005. Raleigh, North Carolina. Presented overview of exposure and uptake modeling to contaminants in drinking water. Also presented procedures used to conduct population-based exposure assessments.

 

SRA 2003 Annual Meeting.  Baltimore, Maryland, USA.  December 7-10, 2003.  Presented paper entitled, “Estimating Multi-Chemical, Multi-Route Cumulative Exposure to Disinfection By- Products (DBPs) in Drinking Water.”

 

The Ninth International Conference on Indoor Air Quality and Climate. Monterey, California, USA. June 30 - July 5 2002. Presented paper entitled, “Integrated Probabilistic and Deterministic Modeling Techniques in Estimating Exposure to Water-borne Contaminants: Part 1: Exposure Modeling.”

 

The Ninth International Conference on Indoor Air Quality and Climate. Monterey, California, USA. June 30 - July 5 2002. Presented poster and paper entitled, “Analysis of Household Water-use Behavior for Use as IAQ Model Parameters.”

 

The 11th Annual Conference of the International Society of Exposure Analysis. Charleston, South Carolina, USA. November 4-8, 2001. Presented paper entitled, “Innovative Approaches for Estimating Exposure and Uptake of Waterborne Contaminants: The Total Exposure Model (TEM).”

 

The 10th Annual Conference of the International Society of Exposure Analysis. Monterey, California, USA. October 24-27, 2000. Presented paper entitled, “Comparing Exposure Classification by Three Alternative Methods: Measured Blood Levels, Questionnaire Results, and Model Predictions.”

 

The Eight International Conference on Indoor Air Quality and Climate. Edinburgh, Scotland. August 8 ‑ 13, 1999. Presented paper entitled, “A Community Comparison of Exposures and Risks from TCE in a Contaminated Groundwater Supply vs. DBPs in a Municipal Water Supply; Part I: Exposure Assessment.”.

 

The 1999 Society of Toxicology Annual Meeting. New Orleans, Louisiana. March 14 – 18, 1999. Operated booth in conjunction with Brooks Air Force Base, Health Risk Assessment Branch. Demonstrated capabilities of the Total Exposure Model.

 

Annual Toxicology Meeting. Wright-Patterson Airforce Base, Fairborne, Ohio. April 11 – 15, 1999. Operated booth in conjunction with Brooks Air Force Base, Health Risk Assessment Branch. Demonstrated capabilities of the Total Exposure Model.

 

The 8th Conference of the International Society of Exposure Analysis. Boston Massachusetts, USA. August 15-18, 1998. Presented paper entitled, “Assessing Multi-Pathway Exposure to Population Groups: The Total Exposure Model.”

 

The Seventh International Conference on Indoor Air Quality and Climate. Nagoya, Japan. July 21 ‑ 26, 1996. Presented paper entitled, “Estimation of Emission Profiles for Interior Latex Paint.”

 

The International Symposium on Engineering Solutions to Indoor Air Quality Problems, sponsored by the Air & Waste Management Association. Research Triangle Park, North Carolina. July 24-26, 1995. Presented poster and paper entitled, “Modeling of Weekly NO2 Concentrations in Residences with Gas Ranges.”

 

The 1994 Joint Conference of the International Society for Environmental Epidemiology and the International Society for Exposure Analysis. Research Triangle Park, North Carolina. September 18‑21, 1994. Presented poster entitled, “Factors Affecting Indoor Inhalation Exposure from a Contaminated Water Supply.”

 

The International Symposium on Assessing and Managing Health Risks from Drinking Water Contamination: Approaches and Applications. Rome, Italy, September 13‑17, 1994. Prepared paper entitled, “Use of Indoor Air Quality/Exposure Model to Identify Important Exposure Factors for Inhalation,” presented by Dr. Julian Andelman.

 

The Sixth International Conference on Indoor Air Quality and Climate. Helsinki, Finland, July 4 ‑ 8, 1993. Presented poster and paper entitled, “A Human Activity-Indoor Air Quality Model for Predicting Inhalation Exposures to VOCs.”

 

Eighth Annual Scientific Symposium of the Ohio River Basin, Consortium for Research and Education. Cincinnati OH, November 11-13, 1992. Presented poster on indoor air quality modeling, and volatile organic compounds.

 

Symposium on Modeling Indoor Air Quality and Exposure, sponsored by: ASTM Committee D22 on Sampling and Analysis of Atmospheres, and its Subcommittee D22.05 on Indoor Air. Pittsburgh, PA, April 27-28, 1992. Presented poster and oral presentation on indoor air quality modeling and volatile organic compounds.

 

The Fifth International Conference on Indoor Air Quality and Climate. Toronto, Canada, July 29 - August 3, 1990. Presented poster and paper entitled, “Air Quality Model for Volatile Constituents from Indoor Uses of Water.”

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TECHNICAL COMMITTEES

 

Montgomery County Public Schools, Indoor Air Quality Steering Committee. Montgomery County, Maryland.

1999 - Present

This committee provides guidance on and oversight of school systems’ activities in regard to indoor air quality issues.

 

Montgomery County Public Schools, Indoor Air Quality Process Action Team. Montgomery County, Maryland.

August 1997 – March 1998

Serving on process action team (PAT) to examine issues related to indoor air quality in the public schools, including the causes and system’s response to complaints.  The goal of the team is to develop a consistent, proactive, countywide strategy for improving indoor air quality in the schools.

 

Montgomery County, Energy and Air Quality Advisory Committee. Montgomery County Council, Rockville, Maryland. December 1995 – June 2003

Serving on committee providing advise to the Montgomery County Council on issues relating to energy efficiency and air quality. The objective of the committee is to promote energy and air quality consciousness in the community.

 

International Life Sciences Institute. Washington, D.C. January 1999 - 2001

Participated in working group on Total Exposure Assessment for Drinking Water Contaminants.

 

International Life Sciences Institute. Washington, D.C. July 1995 – July 1998

Participated in working group on Estimation of Dermal and Inhalation Exposures to Contaminants in Drinking Water.

 

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PROFESSIONAL MEMBERSHIPS

 

International Society of Indoor Air Quality and Climate

International Society of Exposure Assessment

Society for Risk Analysis

American Chemical Society

American Water Works Association

 

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PROFESSIONAL CERTIFICATES


Professional Engineer, 1997


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Last modified: November 2006