Baby teeth studies reveal childhood radiation exposure

 Friday, September 13, 2002

 By Joni Praded, E/The Environmental Magazine

The discovery came last spring. Some Washington University researchers  were wading through a musty old ammunition bunker at Missouri's Tyson Research Center, doing some cleaning.  There they stumbled across a bizarre find: hundreds of boxes containing baby teeth. Each tooth was accompanied by a card carrying details of the child who lost it. There were 85,000 teeth in all, and stumped university administrators nearly discarded them.  Luckily, they didn't; the cached teeth turned out to be a scientific  treasure trove. Over the next few years, they will give researchers  the rare chance to measure how radiation levels in children's bodies affect their health in later life.

 The teeth were unused specimens from the St. Louis Baby-Tooth Survey, a massive public health study mobilized by scientist and antinuclear  activist Barry Commoner from 1958 to 1970.

The United States had been conducting above-ground nuclear weapons tests, setting off about 100 bombs in the American West in the years  following World War II. Radioactive fallout was increasingly detected  in milk supplies and in the environment, and the public was growing  uneasy about how much radiation might be accumulating in their own bodies and what ills it might spur.

Researchers working on the survey collected some 300,000 baby teeth from children in the St. Louis area to see if strontium-90 (a carcinogenic radioactive agent) was accumulating in their bodies. They found that the amount of strontium-90 in those teeth rose dramatically during bomb-test periods and fell dramatically after testing ceased. This helped spur the United States to sign the 1963 treaty banning atmospheric bomb tests.


 But what happened to those St. Louis children later in life? Did their exposure lead to high cancer rates or other illnesses? No one knows, but Joe Mangano and his colleagues at the New York-based Radiation and Public Health Project (RPHP) now have the opportunity to find out. The 85,000-tooth goldmine has been shipped to RPHP's lab, the only place in the United States currently measuring the level of radiation in people's bodies. (The U.S. government hasn't funded such research in nearly 20 years.)

 These modern-day tooth fairies test fallen teeth from children born near nuclear power plants. And like their predecessors, their aim is to find out how much strontium-90 resides in these children's bodies and what impact it has on them. Says Mangano, the St. Louis teeth have provided an opportunity to follow the medical histories of thousands of people with known levels of childhood radiation exposure.

 For countless boomers who strolled around in the 1950s and '60s wearing "I Gave My Tooth to Science" pins, the news of the tooth discovery has revived old questions. As they heard about the find, many of them began contacting Mangano. "So far, 2,150 people have called, and they're all willing to fill out health questionnaires," said Mangano. RPHP's task is to match teeth with owners, analyze radiation levels and health histories, and begin to assess what impact the Cold War fallout had on public health. "It's not an idle look into the past," said Mangano. "It's about the present and the future." And the reason why should pique the interest of every parent, because many of the teeth from today's children show strontium-90 levels as high as those found in St. Louis children at the height of the atmospheric bomb tests.


But where is today's radiation coming from?

 Not from residual bomb fallout, say nuclear experts: Strontium-90 from the bomb tests would have decayed to fairly low levels by now. According to RPHP studies published in peer-reviewed journals, the radioactive agent appears to be highest in children born near nuclear power plants.  Strontium-90 enters human bodies through cow's milk, water, and fruits and vegetables grown in soil exposed to radioactive runoff or  contaminated rainfall. Since it mimics the calcium fetuses and young children need to form teeth and bones, it easily permeates growing bodies. Once there, it can disturb bone marrow -- where the immune system forms the white cells that fight cancer, bacteria, and viruses. All of this, postulate researchers, puts exposed children at risk of leukemia, cancer, and infectious diseases.

Over the past few years, Mangano and his fellow researchers have released their findings on some 2,000 teeth from children born near reactors in five states. In some regions, the researchers have shown that radiation levels and death rates from childhood cancers have grown at an almost identical pace. They have also found that when reactors close, area infant mortality rates improve dramatically, and cancer mortality rates of those over 65 improve even more significantly.

So far, teeth from children born in Miami-Dade County and other southeastern Florida counties have the highest concentrations of strontium-90 in the United States, which might be explained by the fact that two nuclear reactors there emitted 10.39 trillion picocuries of radioactivity into the air between 1970 and 1987, an amount equal to about three-fourths of all the radioactivity released during the infamous Three Mile Island accident.

 In the same region, cancer rates for children under 10 rose 35.2 percent from the early 1980s to the early 1990s, compared to a 10.8 percent rise nationwide, according to one RPHP report. Breast cancer mortality rates are up 26 percent near one of the reactors and 55 percent near the other, compared to a 1 percent increase nationwide. Childhood cancer rates jumped 75 percent in the San Louis Obispo, Calif., area after a reactor opened there. In Pennsylvania, the baby tooth researchers also tracked a rise in childhood cancers that corresponded with a reactor opening. "We think that when you have this documented increase in radiation in the body after the reactor is opened, followed by an increase in childhood cancer, this is strong evidence suggesting a cause-and-effect relationship," said Mangano.


As startling as they are, RPHP findings haven't yet translated into public policy, which worries the researchers more than ever. Little more than a year ago, most pundits were predicting a gradual phase-out of nuclear power in the United States. But now the Bush Administration wants to license new nuclear power plants, and many of the 103 nuclear power plants soon up for relicensing may get a previously unexpected extended lease on life. According to Victor Sidel, past president of the American Public Health Association, "The [RPHP] studies are certainly cause for others to be done. If the findings are the same, then that's cause for social policy to be based upon them."

The odds of other studies getting underway, though, do not appear high. The baby-tooth researchers have had to rely on private grants and direct-mail appeals for funding and volunteers to solicit teeth.

 Connecticut nurse Agnes Reynolds is one of those volunteers. The mother of a 9-year-old boy battling leukemia, Reynolds doesn't know what caused her son's illness. But she does want to know why childhood cancer rates are soaring among children living near nuclear power plants, as her family does. So she asks parents to snatch fallen teeth from beneath their children's pillows and donate them to the baby tooth project. She posts messages to online parenting groups, stocks flyers in waiting rooms, and otherwise helps to get the 3,000 new baby teeth needed for further study. She wants people "to pay attention" to the risks around them. That's a lesson she says she may have learned the hard way. > Unless the government taboo on studying radiation-caused health risks is broken, say researchers, countless others will too.

New Hampshire-based writer Joni Praded covers wildlife and environmental issues for a variety of magazines.

 Copyright 2002, E/The Environmental Magazine