Academic Credentials
  • Ph.D., Toxicology/Ecology, University of California, Davis, 1980
  • M.S., Ecology, University of California, Davis, 1975
  • B.S., Mechanical Engineering, Santa Clara University, 1968
Professional Affiliations
  • American Industrial Hygiene Association
  • Society of Environmental Toxicology and Chemistry
  • Society for Risk Analysis
  • Society of Toxicology

Dr. Sheehan is an ecologist, toxicologist, and risk assessor with more than 30 years of experience conducting human health and ecological risk assessments. He has been recognized as an expert in exposure and risk assessment. 

Dr. Sheehan has managed and conducted human health and ecological risk assessments at contaminated sites, industrial and commercial facilities, residences and for consumer products evaluating chemicals in air, surface water, groundwater, soils, soil vapors, and on the hands, packaging and food items. He specialized in assessing and quantifying potential historical, current and future exposures to chemicals in the environment, workplace and home, and associated health risks.

Dr. Sheehan has designed and directed studies to simulate and reconstruct historical exposures in occupational and residential settings to benzene, MTBE, TCE, PCE and other volatile chemicals in solvents, and asbestos in adhesives, roofing products, joint compound and talc, as well as lead, phthalates, formaldehyde and various other chemicals in consumer products. He has prepared and presented product risk assessments under California's Proposition 65 and U.S. Consumer Product Safety Commission regulations. He has also evaluated potential future chemical exposures associated with new facilities, combustion sources and products. He assists companies develop new products with testing and prospective risk assessment including assessment of allergic contact dermatitis risk from chemical allergens released from electronic wearable products.

Dr. Sheehan also has designed and directed wildlife population assessments, aquatic toxicity tests, toxicity identification evaluations, risk allocation evaluations, and probabilistic uncertainty analyses. Dr. Sheehan frequently interacts with local, state, and federal regulatory agencies, and has testified as an expert before government panels and in legal proceedings on toxicology, exposure and human health and wildlife risks from chemical exposures and has communicated risk issues in public, regulatory and legal forums.