Radioactive particles from Cold War-era nuclear tests found in American honey

WILLIAMSBURG, Va. — During the Cold War, the United States and Russia regularly tested atom bombs throughout the mid-to-late 20th century. Now, a recent study finds the radioactive particles of those nuclear experiments are still present today — and they’re in the food that Americans eat, including honey.

What began as a small spring break assignment for students at William and Mary soon grew into a multi-year study of the lingering effects of Cold War era bombs. Their results? U.S. honey contains significantly more radioactive particles than other foods in the study.

To illustrate how these bombs still linger in our food, Jim Kaste, an associate professor in William and Marys’ Geology department, instructed students to bring back local food following spring break. When measuring the isotope cesium-137, a relic of atom bomb tests, they found honey to have almost 100 times the cesium levels as all other foods.

“I measured it again because I thought something happened to the container or my detector was bonkers. I reproduced the measurement. And it was, again, 100 times hotter than any of these other foods,” Kaste says in a university release.

Kaste began his search to find as many honey samples as he could along the eastern United States.

“Basically, I started by just finding honey producers. I needed to verify that they were local, small-scale honey producers. And so I would email them. We’d order it and once it got here, then we would usually pour it into this 150-milliliter petri dish,” adds Paul Valonte, a student and geologist at William and Mary.

How did radioactive particles travel across the country?

Study authors moved the honey samples to a gamma detector for multiple days, which looked for the emission of gamma particles as the cesium-137 began to decay. Kaste and his team concluded that 68 of 122 samples contained varying amounts of cesium-137. However, Kaste states with confidence the amount is not harmful to the public.

“I eat more honey now than I did when I started this project,” the study author notes.

Kaste proposed a hypothesis as to why and how cesium-137 traveled so far and still lingers in American food products. He explains that the particles likely traveled up into the atmosphere over nuclear test sites in the desert, with winds carrying them east until rainfall brought them back down to the ground. Once the cesium returned to the earth, it remained deep in soil low in potassium.

“Potassium is an important nutrient for plants,” Kaste explains. “And potassium and cesium atoms look very similar.”

Plants low in potassium, primarily in states south of the Carolinas, likely took in cesium as the next best thing. From there, bees collected the cesium while collecting nectar, then biomagnified the cesium during the process of making honey. Kaste concludes that places where potassium levels in soil were lowest also had the highest concentration of cesium-137 in their honey.

The lasting legacy of nuclear testing

The search for cesium in food products is nothing new. Following the Cold War era, the U.S. government conducted tests for radionuclides in food — primarily in drinks. While nothing was ever taken off the market, records show small amounts of cesium-137 are still present in food products 60 years after the country’s nuclear tests.

Kaste hopes his work demonstrates how long pollutants remain in our atmosphere and affect future generations. It is a slow process for cesium and other pollutants to disappear completely, and study authors fear it’ll take even longer for the former Soviet Union — now Russia.

“We know that the cesium-137 production from the Pacific and Russian sites was more than 400 times the production of the New Mexico and Nevada explosions,” Kaste concludes. “A single Russian bomb, the Tsar Bomb, was more than 50 times more powerful than all the Nevada and New Mexico tests combined.”

This study is published in the journal Nature Communications.