OAK RIDGE, Tenn. — A postgraduate student intern and an Oak Ridge Associated University researcher teamed up to replicate the 1976 McCluskey Room Incident, in which a chemical worker now known as “the Atomic Man,” survived the highest known exposure to the radioactive isotope Americium-241 at Hanford Plutonium Finishing Plant in Washington.

The pair is trying to measure the physiological effects of chronic low-dose radiation and establish new data for first responders and clinicians to reference after a radiation incident.

Haorld McCluskey, “the Atomic Man,” told People Magazine in 1984 that he had just celebrated his 40th wedding anniversary with his wife the night he returned to work. The laboratory he worked in had been closed for five months because of a strike.

At the lab, his supervisor instructed him to add nitric acid to columns containing the radioactive isoptope Amercium-241, though the columns were reportedly coated in resins that had been left unattended for months.

When the nitric acid and the resins mixed, the column exploded, showering McCluskey with acid and radioactive material. In that moment he received 500 times the amount of radiation considered safe for a person to endure in a lifespan.

Local media accounts of the August 1976 incident describe McCluskey, blinded and unable to hear well, being remotely evacuated from the laboratory to a concrete isolation tank where he stayed for the next five months.

McCluskey literally exhaled radiation. The Department of Energy told Southeast Washington’s Tri-City Herald that McCluskey’s body set off Geiger counters as far as 50 feet away.

McCluskey went through intense chelating treatments to reduce the amount of radiation in his body.

He was eventually able to go home to his family. He died at 75 of a heart condition unrelated to the incident, to the bafflement of doctors at the time.

ORAU health physicist Jason Davis is working with Daniel DiMarco, a summer intern he is mentoring this summer through ORAU’s new visiting faculty research program to safely replicate the incident.

The pilot program creates teams to tackle research projects that benefit the organization’s work in fields like health physics.

“Reading about the atomic man incident, I read where they had made really good estimates of the total dose delivered to the body, but when they went to analyze the lymphocytes in the body they weren’t able to calculate a direct-dose response,” Davis said.

“Dose response” refers to how the body acts when it is exposed to a certain amount of radiation over time, versus being exposed all at once. Davis and Dimarco want to examine the body’s response to radiation exposure over different lengths of time.

“From a purely scientific perspective, we don’t know a lot about chronic low-dose radiation,” said DiMarco, who is about to begin his master’s degree at Louisiana State University. “We know much more about what happens from accidents. We need a bigger data set.”

Obviously, Davis couldn’t directly expose himself or his intern to the radiation in the same way that McCluskey was exposed to it.

So, the two designed an experiment using a cobalt isotope in a sealed source and used donated vials of their own blood, rather than themselves.

“The nifty thing about radiation dose in the body is that your body doesn’t care where it came from,” Davis said. “The dose is just the amount of energy deposited in a given mass, so it doesn’t matter if it came from a different isotope or even from a medical X-Ray. It’s the total quantity you’re exposed to that matters.”

They irradiated their blood for different lengths of time, mixed it with a culture and put it in an incubator. Then, ORAU researchers added a drug that freezes cells going through mitosis to halt the cells in metaphase: the phase in which chromosomes line up before they split apart.

By examining the chromosomes in metaphase, scientists can see the centromeres that chromosome spindles attach themselves to.

Davis and DiMarco are looking for dicentric chromosomes: ones that have two centromeres. Chromosomes can become dicentric when they are exposed to radiation.

Davis said most people have a few in their body already. “But, when more are visible it’s an indication that you’ve seen some type of radiation exposure above background,” he said.

The student-mentor team harvested the irradiated blood cells Friday and examined them in a microscope.

The donated blood experiment does have its drawbacks, however.

Lymphocytes, a kind of small white blood cell, are constantly dying and repopulating. An irradiated lymphocyte in a blood sample could die off and be replaced by a new one before scientists have time to measure it.

Davis said he hopes that in the future they can perform the experiment on a mouse or a rat to get more accurate results. Irradiating an animal’s body creates a disposal hazard though, so getting that kind of study approved would be difficult.

“You’d be trying to dispose of a material that is both radioactive and a potential biohazard so it’s a mixed waste and it gets difficult there.”

Either way, Davis said the goal is the same. They want to continue the research with greater and greater exposure times and doses to establish data that can better prepare clinicians for what might happen over time to the body of a patient from a radioactive incident.

“In and ideal case, like that of the atomic man, they administered a chelating agent that grabbed a lot of the Americium (isotope) and just cleaned it out of his body,” he said.

“It worked very well, but having the type of information Daniel and I are developing would give the clinicians a better idea of how much of the agent they need to administer and when and if the agent is going to impact other measurements on down the line.”


Information from: Knoxville News Sentinel, http://www.knoxnews.com