Paul Turnham
Paul Turnham, P.E.
Senior Managing Scientist
Health Sciences

Mr. Turnham trained as a civil and environmental engineer and is licensed as a professional engineer. He has more than 20 years of experience working in the fields of quantitative human health risk assessment, site characterization, dose reconstruction, and environmental fate and transport.

Mr. Turnham specializes in the development and application of site and case-specific approaches to risk and exposure assessment for regulatory and litigation purposes. He is experienced in cases involving personal injury (both site and product related), property damage, and public nuisance, bankruptcy, and criminal matters. The work has involved a number of agents of concern including chlorinated solvents, petroleum compounds, heavy metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, dioxins, and asbestos. He has performed individual-specific dose reconstructions and risk estimation associated with human exposures to environmental media, indoor air and dust, and use of consumer products. He has designed and implemented chamber and field activity-based simulations for data collection to support these efforts. He has provided risk and exposure assessments for industrial and residential sites including Superfund, RCRA, and state oversight cleanup sites and for air emissions sources such as hazardous waste-burning cement kilns, coal-fired power plants and coke oven batteries. He has evaluated exposure and risks from vapor intrusion at residential, commercial, and industrial properties; this included the development of a vapor intrusion sampling and analysis plan for a residential portion of a Superfund site. He has also designed and implemented site investigations and remedial actions at sites subject to state regulations, RCRA, and voluntary cleanup programs.

Mr. Turnham is also experienced in supporting due diligence activities for property transfer. His work in this arena has included assessment of physical and operational aspects of manufacturing sites across various industrial sectors and states. He has also conducted facility level audits for compliance with federal and state environmental and health and safety regulations.


  • M.S., Civil Engineering (Environmental Option), Virginia Polytechnic Institute and State University (Virginia Tech), 1994


Licensed Professional Engineer, Virginia, #0402-029004


Moolgavkar SH, Anderson EL, Chang ET, Lau EC, Turnham P, Hoel DG. A review and critique of U.S. EPA’s risk assessments for asbestos. Critical Reviews in Toxicology 2014; Early Online: 1–24. DOI: 10.3109/10408444.2014.902423.

Anderson E, Griffin J, Turnham P. Lessons learned from catastrophic releases to the environment: Catastrophic releases that impact human health can be chronic or acute. Poster presented at Reckoning with the Risk of Catastrophe - Deutsche Forschungsgemeinschaft (DFG) and the U.S. National Science Foundation (NSF) Research Conference, Washington, DC, October 2012.

Turnham P, Richter R, Griffin J. Estimating indoor air exposure concentrations of biodegradable VOCs using API’s BioVapor Spreadsheet Model. Poster presented at Society for Risk Analysis Annual Meeting 2012, San Francisco, CA, December 2012.

Barabas N, Turnham P, Helfand J, Griffin J, Dunkin J. A tiered approach to fingerprinting dioxins—Distinguishing between an HCP manufacturing source and a barrel reconditioning facility. Presented at the 31st Annual Meeting in North America of the Society of Environmental Toxicology and Chemistry, Portland, OR, November 2010.

Turnham P. Field investigation and risk assessment for the vapor intrusion pathway. Presented at the Arizona Department of Environmental Quality and U.S. Environmental Protection Agency meeting of the Motorola 52nd Street Superfund Site Community Advisory Group, Phoenix, AZ, 2005.

Richter RO, Griffin JR, Turnham P, Lau E. Release of Naturally Occurring Arsenic via Reductive Dissolution at Petroleum Contaminated Sites. AEHS Conference, San Diego, CA, March 2017.

Turnham P, Anderson EL, Turim J. Dermal absorption of PCBs in non-aqueous carriers. Presented at the Society of Risk Analysis 23rd Annual Meeting, Baltimore, MD, 2003.

Turim J, Turnham P, Griffin J. Computing asbestos risk using life tables. Presented at the Society of Risk Analysis 23rd Annual Meeting, Baltimore, MD, 2003.

Patrick DR, Turnham P. Multipathway risk assessment of a cement kiln combusting hazardous waste. Presented at the 94th Annual Conference and Exhibition, Air & Waste Management Association, Orlando, FL, June 2001.

Moore MA, Hanna LM, Grumm DM, Turnham P, Yu CP, Jubb GA. Biopersistence of insulation glass fibres. Annals of Occupational Hygiene1997; 41(inhaled particles VIII):312–319. doi:10.1093/annhyg/41.inhaled_particles_VIII.312

Book Chapter

Anderson EL, Lowe K, Turnham P. Chapter 1. In: Cancer Risk Assessment: Chemical Carcinogenesis, Hazard Evaluation, and Risk Quantification. John Wiley & Sons, Inc., 2010.

Prior Experience

Project Director, Sciences International, Inc., 2003–2006

Project Manager, Sciences International, Inc., 1999–2003

Senior Associate, Sciences International, Inc., 1997–1999

Associate, Sciences International, Inc., 1995–1997

Analyst, Sciences International, Inc., 1994–1995

Engineer III, EG&G Washington Analytical Services Center, 1992–1994

Civil Engineer, J.E.M. Van Der Beek Associates (UK), 1988–1990 

Professional Affiliations

Society for Risk Analysis, 2003–present (member)

American Society of Civil Engineers

Project Experience

Managed and provided technical support for litigation projects involving consumer exposure to talcum powder products. One project in particular involved design and implementation of a chamber simulation to replicate alleged usage and obtain data for inhalation exposure assessment.

Managed a project requiring risk assessment support and sampling program design and oversight for asbestos in soils for large land area. Provided technical risk-assessment based support for data quality objectives. Oversaw and directed the team responsible for design of field activity based sampling program.

Managed large projects related to exposure to asbestos from use of historical products and in situ asbestos-containing materials and soils. Estimated exposure and risk for spray fireproofing and attic insulation. Provided human health risk assessment support.

Evaluated vapor intrusion risks and hazards for a large fuel storage terminal site. The assessment evaluated both indoor and outdoor air concentrations. Groundwater and soil gas data were used to provide screening level risk estimates for offsite residents and workers.

Provided technical analysis for litigation involving human exposure to DDT and associated compounds in indoor dust. Gave advice on the appropriate indoor dust sampling protocols for use in exposure assessment and identified the areas within a home that should be sampled for indoor dust health assessment. Provided interpretation of indoor dust data using an exposure and risk model developed by EPA for the World Trade Center. Evaluated risk to adults and children.

Provided litigation support in cases involving exposure to arsenic in indoor dust alleged to be associated with agricultural soil amendment with chicken litter. Evaluated and critiqued indoor dust-to-air models and risk calculations presented by opposing experts.

Provided risk assessment related support to a PRP group at a large Superfund site in New England where dioxin-contaminated sediment is the primary risk driver. Provided comments on USEPA’s draft baseline risk assessment that resulted EPA revising some portions of the document. Developed a site-specific share allocation model using site data, risk assessment, and environmental forensics.

Directed a human health risk assessment to support a voluntary cleanup action at an aircraft-manufacturing site in Maryland. The assessments, performed by tax parcel, evaluated risks to current and hypothetical future residents, recreational users, workers and site visitors arising from potential exposures to substances in soil, groundwater, surface water, sediments and indoor air. Managed all aspects of the project including data analysis, development of spreadsheet algorithms, and creation of innovative techniques to efficiently compute the risks on a point-by-point basis and, using GIS software, to display the results.

Developed a risk assessment work plan for assessment of vapor intrusion into residences at Superfund site in Arizona. The plan was reviewed and approved by the Arizona DEQ and EPA Region 9. Separately evaluated indoor air risk assessment for a commercial site in Arizona. The work that was performed for the Arizona DEQ, involved integration of indoor air data, modeled indoor air concentrations from vapor intrusion and ambient outdoor air data.

Performed a re-assessment of baseline human health risks for litigation for a Superfund site in Pennsylvania where PCBs were the main contaminants of concern. Notable was the re-assessment of dermal exposure to PCBs in oil, which was disseminated at the 2003 annual meeting of the Society for Risk Analysis.

Evaluated potential exposures to coke oven emissions and evaluated EPA’s assessments of risk associated with emissions from U.S. coke oven batteries. Assisted in the development of a presentation and report on the results of the study to EPA's Office of Air Quality, Planning and Standards (OAQPS). Assisted in the development of a revised methodology for dispersion modeling for coke oven batteries. Later presented this methodology to the OAQPS along with case studies. The agency subsequently adopted the methodology in its risk assessment for rulemaking under the Clean Air Act’s residual risk program. He later managed the application of the air dispersion methodology for coke oven batteries sites. Also reviewed the risk assessments performed by OAQPS, which were based on that methodology.

Conducted a multi-pathway/multimedia risk assessment for cement kiln burning hazardous waste in 1997/98. Developed spreadsheet-based algorithms which modeled the fate and transport of over one hundred chemicals including dioxins and mercury emitted from this site into the following direct and indirect exposure pathways: inhalation, ingestion, and dermal absorption of soil and surface water, ingestion of homegrown fruits and vegetables and animal products. The work included selection and application of fate and transport models to estimate chemical runoff into surface water bodies, uptake into fruits and vegetables, and bio-transfer into animal products. Risks were estimated for residents including the mother’s milk pathway (for dioxins), subsistence farmers, recreational anglers, hunters, and swimmers. The risk assessment was submitted to USEPA and the state and was subject to public comment. USEPA Region 3 and the state of Pennsylvania subsequently endorsed the risk assessment. Led subsequent work on this project including a quantitative assessment of threshold effect risks for dioxins using the margin of incremental exposure approach and assistance in developing a risk-based protocol by which to measure future compliance.


  • M.S., Civil Engineering (Environmental Option), Virginia Polytechnic Institute and State University (Virginia Tech), 1994


Licensed Professional Engineer, Virginia, #0402-029004