Dr. Ed Calabrese is a professor of toxicology at the University of Massachusetts in Amherst, MA. For the past twenty years, he has focused his research on understanding the response of a variety of organisms and tissues to a variety of chemicals and radiation as doses vary from extremely low to quite high. He is one of the world’s leading experts in the general scientific field of dose response.
The first third of this interview focuses on Dr. Calabrese’s career turn from toxicology in general to dose response in particular as he relates the story of his initial interest in the subject as the result of a laboratory mistake as an undergraduate. That mistake turned into a series of experiments and his first published paper, but it also encouraged him to find a different career path that focused more on chemical toxicity for animals rather than plants.
The remaining part of the interview traces Dr. Calabrese’s more recent efforts to understand the roots of conventional wisdom in the field of dose response. In these efforts, Calabrese has returned to an early academic interest in studying history. For his first semester as a freshman in college, Ed Calabrese was a history major. After exposure to science courses he realized he was more interested in pursuing a scientific career than one in history, but he never lost the history gene — as he put it.
Aside: I recently spoke to a history professor at the University of Virginia, During our conversation, I inquired about the possibility of entering their graduate program. He was quite discouraging about career opportunities in the field. He was much more supportive of my interest when I made it clear that I was not looking for a new career, just new knowledge. End Aside.
The story that Dr. Calabrese has uncovered and meticulously researched though original source material like correspondence and academic papers is one that has had a major impact on all of our lives, even though it might have started with a rather innocuous beginning.
Hermann Muller, a Nobel Prize winning geneticist, had decided by the late 1920s that radiation harmed living organisms by damaging DNA in direct proportion to the amount of radiation achieved. For each “hit” of radiation there was a finite, greater that zero chance of a damaging event and no possibility of positive events that might result in an overall positive effect — at least that is what Muller thought and what he taught to a number of disciples.
Though he marginalized himself through his political activities and spent most of the 1930s running genetics research programs in the Soviet Union, Muller returned to the United States at the beginning of World War II. Despite his scientific publications and accomplishments, the best job he could find in the US was a job teaching at Amherst College, a small undergraduate school in the same town where Calabrese teaches today. He did some paid consulting work for researchers working on the Manhattan Project at the University of Rochester; he was one of the few scientists at the time who had any experience at all in testing radiation responses on living creatures.
The University of Rochester hosted two research efforts on radiation effects associated with the Manhattan Project, one involving more than 250,000 mice and one involving Drosophila — the fruit flies that Muller had been researching since his graduate days at Columbia before WWI.
The mouse research data was essentially lost and resulted in only two documents published more than a decade after the end of WWII, so, by default, the information extracted from the Drosophila experiments was the basis for post war radiation effects assumptions.
Dr. Calabrese has published detailed, peer-reviewed papers about how Muller’s determination of a linear response mechanism based on the “hit theory” became accepted, despite the discovery of inconvenient evidence by his own associates that falsified the theory and indicated that radiation effects on complex living organisms could not be explained by a straight line or even a straight line with a fudge factor like the dose and dose rate effectiveness factor applied to certain regions in the linear model.
During this interview, Calabrese shares the story he has uncovered and demonstrates that he not only has a gift for science and history, but he also has the gift of gab. My guess is that he is a popular lecturer at his university; I couldn’t believe that we had been talking so long once his story was finished.
I hope you enjoy this episode of the Atomic Show and share it widely.