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Black in STEM


James Walker

James T. Walker, Ph.D.


Major and Degree: Physics, Ph.D.

Graduation Year: 1982

Current Position: Retired Senior Environmental Scientist, U.S. Environmental Protection Agency


Connect: Email


What motivates you to do/pursue science and/or medicine?

I have always been interested in determining why and how the mechanism in the universe and beyond it works. I've constantly sought to obtain explanations for naturally occurring patterns or events and to use those explanations to develop laws or models, so that mankind can better understand and make predictions about the natural world that we live in.

What does Black History Month mean to you?

To me, Black History Month means a month when we honor and celebrate the accomplishments and contributions of all "Black" African American U.S. citizens.


Anything else you would like to share?

I was the first African American to matriculate in and graduate with a doctoral degree from Penn State's physics department.

Starting in 1982, I worked as a senior scientist at the National Council on Radiation Protection and Measurements (NCRP) and the U.S. Environmental Protection Agency (EPA). I served with national and international scientists on many scientific committees and assisted in the development of NCRP reports, which provided guidance to the scientific community on human radiation exposures occurring during space travel and medical diagnoses and treatment activities. At the EPA, I worked as a senior environmental scientist in the development of internal radiation dosimetry models for assessing radiation exposures and risks to growing children. 

I retired from the EPA in 2017. However, I am working on developing and publishing, in the scientific literature, a mathematical model for describing height growth in children from birth to maturity.