First an inspired but unproven idea went viral in an unlikely social network. Then crowd-sourced science did what seemed impossible: stopped above-ground nuclear weapons testing at the height of the Cold War. #UpliftingSTL

The Greater St. Louis Citizens’ Committee for Nuclear Information was formed in 1958 by concerned medical professionals, researchers, and others to raise public understanding about nuclear hazards.

They knew that a by-product of nuclear weapons testing is death-dealing, cancer-causing radiation. Some elemental isotopes last for thousands of years while others decay quickly, but airborne debris drifts for miles from explosions, falling onto food and water.

Hundreds of above-ground tests needed to quickly be stopped. The St. Louis Baby Tooth Survey, organized by the citizens’ committee, accomplished just that. Beginning in 1959, the committee sent out a call for parents to send in their kids’ baby teeth.

News media, schools, scout groups, churches, and others organized to get the word out for samples to analyze.

What researchers were looking for was the strontium-90 levels found in the baby teeth.

Strontium-90 is a low-level radioactive isotope not found in nature. Inadvertently consumed by a growing body, it’s deposited with calcium in bones and teeth.

Baby teeth develop, mature, and are replaced by adult teeth at a certain rate, so testing them for this isotope could reveal how much fallout was getting to people and when exposure occurred.

The committee collected 320,000 baby teeth and what they found was shocking: The strontium-90 levels in children’s teeth in 1963 was 50 times what they were in 1950 and the levels rose and fell in correlation with atomic bomb tests.

The immediate radiation danger moved public opinion, which influenced Congress to pass and President John F. Kennedy to implement the Limited Test Ban Treaty in 1963.