Katherine D. Walker, ScD

Biography

Katherine D. Walker is a Senior Research Associate with the Harvard Kuwait Project. She has 20 years of experience in
the evaluation of environmental health risks and their role in decisions about public health protection. Her particular
focus has been on the analysis of variability and uncertainty in human health risks and on the use of expert subjective
judgment for that purpose. She has published research on the elicitation of probabilistic expert judgments about
uncertainty in ambient, indoor, and personal exposures to benzene. It was one of the first studies of subjective
expert judgment to assess quantitatively the quality, or calibration, of the experts’ judgments about an
environmental exposure. For the USEPA Office of Air and Radiation, she recently completed an elicitation study with
Industrial Economics, Inc. to characterize uncertainty in the relationship between long-term inhalation exposures
to fine particulate matter (PM2.5) and premature mortality in the U.S. This work will provide probabilistic estimates
of the concentration-response relationship for EPA’s analyses of the benefits of proposed regulations to
reduce PM2.5 emissions. Dr. Walker is a member of the USEPA’s Science Advisory Board on EPA’s White
Paper on Expert Elicitation. She holds a B.A. in Biology from Bowdoin College and M.S. and Sc.D. degrees in
Environmental Health Sciences from the Harvard School of Public Health.