Kids Mailed 320,000 Baby Teeth to Help Stop Nuclear Tests

Between 1958 and 1970, children in and around St. Louis handed over nearly 320,000 baby teeth to scientists, according to the New York Times. In return they got a button that read "I gave my tooth to science". Those teeth proved that fallout from nuclear bomb tests was ending up inside children's bodies, and the findings reached President John F. Kennedy while he negotiated a ban on tests in the atmosphere.

The worry was strontium-90, a radioactive isotope made in nuclear explosions. It behaves chemically like calcium, so fallout that settled on pastures moved through cows' milk into growing bones and teeth. From 1945 to 1963, the Times reported, the United States set off 206 nuclear weapons in the atmosphere and the Soviet Union 216.

The idea of using teeth came from biochemist Herman Kalckar, who proposed an international census of radiation in milk teeth in Nature in August 1958. Baby teeth form before birth and in the first months of life, so each one keeps a record of what a child absorbed at that age, and children lose them on their own.

In St. Louis, the Greater St. Louis Citizens' Committee for Nuclear Information, founded in April 1958 by scientists such as botanist Barry Commoner and local citizens, launched the survey in December 1958. Physician Louise Reiss directed it, working with the dental schools of Washington University and Saint Louis University. Washington University's Becker Library notes that a first federal grant of 197,454 dollars paid for the laboratory.

The campaign was a feat of local organizing. Volunteers sent collection forms to public, private and parochial schools, libraries and even drugstores. The Missouri Encyclopedia recounts how children's TV shows such as Romper Room promoted it, how young donors joined an Operation Tooth Club, and how the lab's radiation counter was shielded with steel plates cut from the hull of a World War I battleship.

Reiss published the first results in Science on 24 November 1961, showing strontium-90 rising in children born through the 1950s. The Bulletin of the Atomic Scientists notes that levels tripled in just three years in the early 1950s. The final tally was stark: children born in St. Louis in 1963 had about 50 times as much strontium-90 in their teeth as those born in 1950, before most of the tests.

In June 1963, her husband, physician Eric Reiss, presented the findings to a Senate committee in support of a treaty. On 5 August 1963, the United States, the Soviet Union and Britain signed the Partial Test Ban Treaty in Moscow, banning nuclear explosions in the atmosphere, in outer space and under water. Kennedy signed the American ratification on 7 October.

The ban worked. A later phase of the survey found 50 percent less strontium-90 in children born in 1968 than in those born five years earlier, and the Bulletin says levels in milk, baby teeth and human bones fell by more than half within five years of the treaty.

The teeth still matter. In 2001, Washington University found tens of thousands of untested teeth, each in a small envelope with a card naming its donor, stored in an old ammunition bunker outside St. Louis. The Harvard T.H. Chan School of Public Health estimates there were about 100,000 from some 55,000 donors, and more than 6,500 of those grown-up children have joined its study of their later-life health.

Sources: The New York Times (2011); Nature (1958); Science (1961); Becker Library, Washington University; Missouri Encyclopedia; Bulletin of the Atomic Scientists (2023); US Department of State; Harvard T.H. Chan School of Public Health. Cover: President Kennedy signs the Nuclear Test Ban Treaty, 7 October 1963, Robert Knudsen, White House, public domain.