Dr. David M. Lehmann is an accomplished toxicologist with nearly 20 years of cross-sector experience across academia, industry, and government, applying toxicology principles to questions involving drugs, alcohol, and chemical exposures. His expertise includes toxicology, pharmacology, toxicological mechanisms, drug-related signal transduction pathways, human health risk assessment, and the interpretation of complex scientific data in both scientific and legal contexts.
Dr. Lehmann currently serves as a Senior Toxicologist at Intertox, where he provides toxicological analysis, expert reports, and testimony in matters involving drugs, alcohol (liquor liability and dram shop), environmental exposures, medical devices, and consumer products. His work includes case review, evaluation of toxicological data, exposure assessment, dose reconstruction, and weight-of-evidence causation analysis. He supports both civil and criminal matters and has experience working with attorneys representing both plaintiff and defense.
Prior to joining Intertox, Dr. Lehmann spent 15 years with the U.S. Environmental Protection Agency (EPA), where he served as a Senior Toxicologist and risk assessor. In that role, he evaluated the human health effects of chemical exposures—including substances affecting the central nervous and immune systems—and contributed to major federal scientific assessments. His work involved critical review of toxicological evidence and clear communication of scientific findings to both technical and non-technical audiences.
Dr. Lehmann has a strong foundation in alcohol and drug toxicology, including pharmacology of central nervous system (CNS) depressants and stimulants, cannabinoids, and other psychoactive substances. His doctoral research examined the biological effects of ethyl alcohol, and he has continued to build on this foundation through teaching, professional training, and applied toxicological work.
He supports attorneys and other clients by applying scientific evidence to questions involving alcohol and drug effects, exposure, and potential impairment, and by translating complex toxicological concepts into clear, understandable opinions for legal audiences.
Dr. Lehmann holds a Ph.D. and M.S. in Toxicology from the University of Rochester School of Medicine and Dentistry and a B.S. in Biological Science from Colorado State University.