LAWRENCE, Kan. • The wind whistled innocently through the opening in the sliding glass door. Rushing in from a buttermilk sky, it gave no hint of radioactive traces from damaged nuclear reactors thousands of miles away.
The old man was not afraid. He welcomed any radiation that might blow in. He would have risen from his blue recliner in the living room and opened his arms to the invisible rays if he could somehow know they were there.
Don Luckey is 91. He has a full face and white beard. His blue eyes are failing. His hearing is fading. His balance, he recently noticed, has grown unsteady. He's getting toward the end, near as he can tell.
But he has work still to do, work on radiation begun 50 years ago as a respected biochemist at the University of Missouri-Columbia. His studies on antibiotics and pesticides earned him acclaim. But his work on radiation had always been controversial, running so against the established thinking, even as resistance has softened with time. He thought he was done with it. In his garage, boxes of research wait for shipping to a school repository. But then the invisible rays spilled from those reactors in Japan, seeding fresh worry.
Luckey believes we actually live in a deficiency of radiation. And, he says in the gruff, bulleted tones of someone accustomed to being doubted, "if we get more radiation, we'd live a more healthful life."
He is the modern father of this provocative theory, which has riled and intrigued scientists for decades. He also lives it.
On a bookshelf next to his bed, just inches from where he sleeps, sits a jagged brown rock, about the size of a small bowling ball, dotted with flecks of uranium, spilling invisible rays.
Radiation is seen as a dangerous phantom — both poisonous and invisible.
And radiation is as much a political issue as a scientific one, with clashes among anti-nuclear activists, power companies, researchers and governments.
It stirs thoughts of cancers and birth defects, nuclear weapons and fallout, Three Mile Island, Chernobyl and now Fukushima Daiichi. Calling it beneficial seems like a hoax, a polluter's dream.
Yes, Luckey says, radiation is a poison. But high doses and low doses have opposite effects.
High doses kill and sicken. Lab research and studies of atomic bomb survivors from Nagasaki and Hiroshima proved that. But, he says, low levels bolster the body and extend life spans. The effect is called hormesis, from the Greek word for "excite."
"It's true of most agents on earth," says Luckey. "And it's true of radiation."
Luckey is not alone in wondering if science understands the effects of low-dose radiation, which covers almost all accidental radiation exposures.
The releases in Japan so far have been one-tenth of those from Chernobyl. In the Three Mile Island accident, residents nearest the reactor received the equivalent of a single chest X-ray. Even without accidents, radiation is everywhere — pouring from the sun and rocks. It is measurable in bananas, computer monitors and granite kitchen countertops. Yet it makes people uneasy: Three years ago, a rush of alarming media reports about radioactive countertops forced the U.S. Environmental Protection Agency to address the issue and confirm that the doses were negligible.
With high doses so rare, it is with low doses that the fear rushes in.
Data on health risks from low-dose exposures generally do not exist. Low-dose exposure is difficult to measure. So scientists and regulators extrapolated the risk known from high doses and arrived at an estimate: Low doses must cause cancers and deaths, just fewer of them. It is called the linear, no-threshold model. The LNT.
The LNT is the official position of the United States. It is reaffirmed by the National Academy of Sciences every few years. But the last 20 years have seen a surge in the number of scientific papers doubting the model. In 2005 the French Academy of Science and France's National Academy of Medicine broke with the LNT, doubting whether a discernible connection existed between cancer and low-dose radiation.
Even scientists who agree with the LNT model — and think Luckey is wrong — have concerns about how the risk of low-dose radiation is perceived, especially now with Japan.
"Fear of radiation kills more people than radiation does," says Henry Royal, associate director of nuclear medicine at Washington University's Mallinckrodt Institute of Radiology, who has studied low-dose radiation and health effects at Chernobyl, the world's worst reactor meltdown.
The Fukushima incident is not expected to come close to Chernobyl in terms of health effects.
After the 1986 incident, some researchers predicted 40,000 radiation-related deaths would soon follow, Royal recalls. About 6,000 cases of thyroid cancer were believed to be radiation-induced, most of them in children drinking milk from cows feeding on contaminated grass, a risk that is easily managed, Royal said. But the total number of all deaths, including adults, was fewer than 50, he said.
Many scientists, including Royal, believe the largest health effect to come out of Chernobyl was psychological: People were unwilling to plan for the future because they were certain that they would soon die and that any future children were doomed.
No increase in birth defects or genetic problems was found. And yet, Royal says, an estimated 50,000 abortions across Europe are believed to have been related to concerns about Chernobyl fallout.
The fear of radiation has a cost, too.
Luckey is not a "radiation guy." He is a biochemist.
Raised in Wyoming, he earned his doctorate in biochemistry and nutrition from the University of Wisconsin in 1946. He traveled the world delivering speeches and conducting experiments. He consulted on astronaut nutrition for seven NASA Apollo missions.
He first stumbled upon hormesis at Wisconsin. With World War II over, scientists finally were able to get their hands on antibiotics for research. Luckey was researching the effect of bacteria on vitamin deficiencies in animals. He injected baby chicks with tiny amounts of antibiotics, too little to actually do anything. Unexpectedly, the chicks thrived. He expanded into turkeys. Same result.
"I got the concept and could predict that high doses and low doses would have opposite effects," he says.
In 1954, he joined the University of Missouri's medical school as chairman of the biochemistry department. He conducted an experiment exposing crickets to diluted doses of pesticides. The crickets grew more quickly. He published the results. A flood of reprint requests came in.
"So," he says, "I just figured that radiation should be hormetic also."
He needed some radiation, and he found it in a bland research park near Memorial Football Stadium. The university has its own small nuclear reactor, used only for research.
He exposed plants raised in total darkness to varying doses of radiation. The invisible rays promoted photosynthesis.
He decided to write a book about hormesis, a sweeping history. But he kept coming back to radiation. He found hundreds of studies he believed showed the effect. In 1980, he published "Hormesis with Ionizing Radiation."
He keeps a hardback copy in a corner bookshelf, stored with his dozens of other books and publications, under a picture of the Mesopotamian hero Gilgamesh on the living room wall.
The book 'started a big debate," Luckey says. Conferences were held. The theory was debated. Other researchers got interested.
"He had a galvanizing effect on the field," says Edward Calabrese, a toxicology professor at the University of Massachusetts-Amherst, who has taken on a leading role in the study of hormesis.
Sitting in his blue recliner, Luckey looks over the book and flips toward the back. He reads aloud a short passage.
"That's pretty good, isn't it?"
What Luckey described was not new. It just seemed to have been forgotten.
A poison's paradox has been a feature of science for centuries. The 16th-century physician Paracelsus noted that only the dose makes something poisonous. In the late 1880s, scientists studying yeasts developed the Arndt-Schulz law, finding that heavily diluted poisons were actually good for organisms. But Luckey and others are quick to point out that hormesis is different from homeopathy, which claims to use vanishingly small doses as remedies.
Scientists do not fully understand how hormesis works. But it appears that small, yet discernible doses of poison cause cells to erect defenses that can be protective against other problems. A tiny stress to the system seems to prepare it for bigger threats. It's a workout for the immune system.
"You're really dealing with a concept that is very broad, very biological and very fundamental to all forms of life," Calabrese says.
Researchers can point to thousands of studies claiming to show hormesis. Rats given a little dioxin or a dusting of DDT did better than control groups. So did mice or bacteria given minute amounts of drugs. Very low doses of the dreaded neurotoxin methylmercury have been shown to enhance nerve cells. Algae, plants and animals have displayed benefits from low-level radiation in the lab.
"In laboratory studies, it's real," says John Leslie Redpath, a professor of radiation oncology at the University of California-Irvine, who has studied low-dose radiation and remains unsure if it has an hormetic effect. "So it's not unreasonable to expect to see the same hormetic response in humans."
But researchers can't expose people to radiation just to see what happens. They must find people exposed for other reasons and try to work backward to a conclusion. So studies involving radiation — and there are thousands of them — are more open to debate.
The findings are intriguing, though, such as a 1995 study that showed that lung cancer deaths fell as home radon concentrations rose, suggesting radioactive radon gas is protective against the disease. And studies showed lower cancer rates for people living at high altitudes — cities such as Denver — where the background radiation rates are naturally elevated and, according to the linear, no-threshold model, cancer rates should be elevated, too.
Scientists examined the residents of a 1,700-unit apartment complex in Taiwan built with materials heavily contaminated by radioactive cobalt-60. The 10,000 people who lived there for many years had drastically reduced rates of cancer and birth defects, compared with other Taiwanese residents.
"That's what I would expect to happen," Luckey says without surprise.
The most intensely studied population are the atomic bomb survivors. Researchers estimated radiation exposures based on where someone stood — inside or outside, behind a hill or on top of one — when the bombs were detonated. Studies showed the 105,000 survivors suffered an excess of leukemia deaths. Other studies showed survivors outlived their nonexposed peers. And yet other studies showed some long-term risks, but not as dramatic as expected: The medical journal Lancet reported survivors who received a low dose of radiation died an average of about two months earlier than nonexposed people.
Calabrese was a skeptic.
One of the nation's leading toxicologists, he believed what remains the dominant thinking on poisons aside from radiation: The risk is proportional to the dose — a straight line — and below a certain threshold there is no effect. This is how the U.S. government regulates toxic substances such as lead in air and arsenic in water.
For radiation, the rules are even stricter: No safe threshold exists. Calabrese wrote textbooks based on this thinking.
"My interpretations were pretty much wrong," he says now.
Calabrese redirected his career after he read through the scientific literature. He started the International Dose-Response Society and a related scientific journal dedicated to looking at hormesis.
"There's a culture of fear in this country based on the belief there's no safe dose of ionizing radiation," Calabrese says. "There's no doubt it is mutagenic, carcinogenic. The question is whether the relationship is linear. That's where the battle is."
A decade ago, the U.S. Department of Energy stepped into the fray, forming a group to research the effects of low-dose radiation. The chief scientist was Antone Brooks, a now-retired professor of radiation toxicology at Washington State University Tri-Cities in Richland, Wash.
"Researchers all over the world are trying to understand action down in that range," said Brooks, who left the research in 2008. Looking at cells, "they respond in a way that's very different than with a very large dose."
Brooks said the research had changed some scientific thinking, but not enough for the United States to tweak the LNT.
"Every bit of evidence suggests the LNT is overly conservative, that the effect is nonlinear," Brooks said. "But to say it's beneficial, we're not to that point."
And the research may never get there.
But, Brooks said, the public's reaction to the Japan nuclear incident — a rush in the U.S. on powdered milk, Geiger counters and potassium iodine pills to avoid thyroid cancer — shows the degree of misunderstanding about radiation.
"We've scared the devil out of the public about radiation," he said. "And that's a huge mistake."
Not even everyone in Luckey's family agrees with him about radiation.
He has three daughters; one thinks he's right, one thinks he's wrong — and Donna Luckey, she doesn't know quite what to think.
Donna Luckey, who is a University of Kansas architecture professor and the reason he lives in Lawrence, describes her father as an "inscrutable leprechaun" who likes to tease and joke. He can be irreverent. His home is decorated with his collection of more than 200 brass door hooks from all over the world, with designs including horse heads, elephant trunks and antlers. In his bedroom he keeps a formal samurai suit and sword on display — gifts for speeches in Japan. He has an ornate scroll declaring him an honorary knight of a German castle, another gift for his work. This leads him to sometimes sign his correspondence "Sir Samurai T.D. Luckey, PhD."
It can make him seem unserious. But Luckey has nothing left to prove, nothing to sell.
"I feel what I'm doing is important," he says.
And in Luckey's bedroom sits that rock, casting its invisible rays. He picked it up at a radon mine in Montana years ago. Recently, the old man noticed a small red splotch on his lower back. It looked like a mild sunburn, the first sign of too much radiation.
So he pushed the rock back on the shelf, a few inches farther away, just to be safe.