What The Heck Is Health Physics?

The name sounds like it is all about pendulums and inclined planes, but it is really about radiation protection. The most entertaining story about the origin of the job description “health physicist” is that it came about during the “Manhattan Project” when scientists needed to protect themselves from the radioactive materials they used. According to the story, the term, “health physicist” was chosen to be an intentionally confusing description to disguise the work on the atomic bomb.

Over the last 60 years, health physics has developed into an important and complex scientific discipline and profession. There are entire university degree programs devoted to it as well as professional-level certification. In keeping with the confusing name, health physicists have many confusing terms and units such as rem, rad, roentgen, effective dose equivalent, and committed dose, just to name a few. If that weren’t confusing enough, health physicists also use the international system of units (kind of like the metric system).

Today many health physicists work in nuclear power plants, hospitals and industries, all places where radiation is used. Some also work at EPA, since EPA is the primary Federal agency charged with protecting the public from the harmful effects of radiation. Many of them became involved in health physics because they were interested in the science of radiation. I once had a manager tell me that health physicists were unique at EPA because they were the only ones who “thought their pollutant was cool.”

I think the hardest job health physicists have is explaining radiation to the public and to other scientists at the EPA. We know a lot about radiation, but for low level radiation exposure, there is a lot that we need to assume and estimate, and many areas where the science is not clear. I usually start out my discussions about radiation by reminding people that this is a radioactive world.

Did you know that the reason the Earth’s core is still molten after 4.5 billion years is that the long-lived radioactive decay in the core keeps it hot? Without that molten core, Earth would not have a magnetic field, and without a magnetic field the solar wind would have blown away our atmosphere long ago (like Mars). And of course without an atmosphere, Earth would be a lifeless rock. So in a way, radioactivity is the reason there is life on Earth. Health physicists think that is cool–just ask one.

About the Author: Richard Poeton is a health physicist. He started his career with EPA while studying for his MS in radiological science at Oregon State University. Richard is professionally certified by the American Board of Health Physics, and has more than 30 years of experience in radiation protection. He has worked in the EPA Region 10 Seattle office since 1991 and is currently the radiation program manager there.