evidence to support "natural radiation" sources from the Earth are needed for a healthy immune system,

Radiation as health measure? UW emeritus prof thinks so; others not convinced

Eat fruit. Get your exercise. Don't stay out in the sun too long. And for heaven's sake, get some radiation.
Radiation? Not too many buy that last statement. John Cameron knows that. But he's still trying to sell the idea.
"I propose that radiation is like orange juice, it's for your good health," said Cameron, who is 79 years old. "I'm not sure people will get the analogy. But you've got to get your vitamins." Cameron, a UW-Madison emeritus professor of medical physics, radiology and physics, is credited with inventing the photon absorption method of measuring bone mineral density, the standard technique for evaluating osteoporosis.
Of course, he believes high-dose radiation isn't good for you, unless it's radiation therapy combating cancer. But he points to several studies that he believes make the case that a moderate intake of radiation is a good thing. He believes that for reasons unknown, radiation stimulates the immune system.
"It contradicts what they've been telling people about radiation," Cameron said. First, he cites a 1988 study of nuclear shipyard workers who were exposed to low doses of radiation. Although the study found no health risks associated with low-dose radiation exposure, their cancer death rate, as well as overall death rate, was significantly lower than a control group.
He also points to a British study which shows that members of a radiological society, exposed on a regular basis, had a significant decrease in mortality. Earlier radiologists, who had a higher exposure, showed increased cancer rates, Cameron noted.
An article on survivors of the atomic bombs in Japan during World War II showed that those survivors who were 2.8 kilometers from ground zero had greater longevity than those closer or farther away.
Cameron, who founded and nurtured the UW-Madison medical physics department, has many admirers, but they are also among his greatest critics when it comes to his beneficial radiation theory. One of them is Kelly Clifton, an emeritus professor of human oncology and a longtime colleague of Cameron's.
Clifton said it is impossible to know whether a little radiation is harmful, but he doesn't take the studies Cameron points to at face value.
"I don't believe it's necessary to convince people that a little radiation is good for you to help them know it ain't bad for you," Clifton said.
UW-Madison Chancellor John Wiley, himself a physicist, also had mixed reviews for Cameron's theory.
"I find it interesting. I am firmly convinced there's a lot of public misunderstanding and irrational fear of radiation," Wiley said. But he added: "Small levels of anything are difficult to document scientifically."
Cameron said studies show that people who live in the Gulf states of Louisiana, Mississippi and Alabama have a 25 percent higher cancer mortality rate than those who live in the three mountain states of Idaho, Colorado and New Mexico. The radiation level is three times higher in the mountains, he added.
"All we can conclude from these studies is that for good health, we need much more radiation than most of us are getting from nature," Cameron said.
The U.S. Department of Energy funds studies on the harmful effects of radiation, but won't go near talking about the benefits of radiation, he added.
Proposing a study, Cameron suggested putting natural radioactive sources under subjects' beds that would simulate the level of radiation in the mountains. The study would be double-blind: Neither the caregivers nor the participants would know whether the box had radioactive materials or sand.
He doubts such a study will be done soon, but he'll push for one as long as he can. "I may not live to see the results of it, but I'll enjoy the fight," he said.