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Russell E. Keenan, Ph.D.

Russell E. Keenan, Ph.D.

Dr. Russ Keenan is a toxicologist with 25 years of experience specializing in chemical risk assessment focused on the potential human health and ecological risk of organic and inorganic chemicals and on time-dependent probabilistic risk assessment methods. He directs a team of scientists in evaluating risks associated with chemical exposures at a number of sites involving multiple exposure pathways.

John Samuelian, Ph.D.

John Samuelian, Ph.D.

Dr. John Samuelian has more than 30 years of experience in environmental consulting, analytical chemistry, database development, human and ecological risk assessment, quality assurance, site investigation design, and remedial alternatives evaluation. His projects have included PCB and dioxin sites, municipal and industrial landfills, arsenals, pulp and paper mill sites, contaminated sediment sites, radiological sites, and solvent waste sites.

Patrick O. Gwinn

Patrick O. Gwinn

Mr. Patrick Gwinn has more than 25 years of experience applying his expertise in human health and ecological risk assessment, water quality, fate and transport dispersion modeling, product stewardship, air toxics sampling, and hazardous waste management. He has been instrumental in developing and leading projects aimed at establishing site-specific ambient water quality criteria and pollutant discharge limits.

R. Dreas Nielsen

R. Dreas Nielsen

Mr. Dreas Nielsen specializes in quantitative analysis of environmental data. His scientific expertise is principally in the areas of sediment contamination, chemical bioaccumulation, biological effects of contaminants, and chemical transport and fate. His approach to scientific topics stresses analytical and quantitative methods, with an emphasis on computer applications.

Bridgette R. DeShields

Bridgette R. DeShields

Ms. Bridgette DeShields has 27 years of experience and is a specialist in regulatory strategy, site investigation, site remediation, sediment and water quality management, and environmental toxicology. She has managed programs ranging from large site investigations to screening and quantitative ecological and human health risk assessments.