Between 1945 and 1996, over 2,000 nuclear explosions were detonated worldwide by the United States, the USSR, and other countries. Over 500 nuclear weapons were tested in the air. These bombs dumped radiocesium, cesium-137, into the atmosphere, and they would soon fell back to the earth with rain unevenly according to the region's climate.
Now, according to a new study published in Nature Communications, scientists have found that the fallout from nuclear bomb tests of this era can be found in U.S. honey.
This shows that, even after 50 years after these nuclear tests, radioactive fallout still surrounds us in a way, cycling through plants and animals in nature.
Radiocesium in nature
But how does such a thing happen? It is actually quite straightforward: since radiocesium is soluble in water and shares similar chemical properties with potassium, plants can mistake the two.
In an attempt to understand whether plants still continue to take up radiocesium, James Kaste, a geologist at the College of William & Mary in Williamsburg, Virginia, instructed his students to bring back local foods from their spring break destinations, per a press release by the university. Their samples would be tested for radiocesium.
Tests showed that honey from Raleigh, North Carolina contained cesium levels 100 times higher than the other foods. In order to study this further and test them for radiocesium, Kaste and his colleagues collected 122 samples of locally produced, raw honey from across the eastern U.S.
Radiocesium was detected in 68 of the samples, at levels above 0.03 becquerels per kilogram which means roughly 870,000 radiocesium atoms per tablespoon. A Florida sample had 19.1 becquerels per kilogram, which was the highest level of radioactivity for this sample study.
Should you worry?
Before you start panicking, you should know that the current levels of radioactivity aren't deemed to be dangerous. The U.S. allows 1,200 becquerels per kilogram in all food, and the radiocesium levels reported in this new study "are nothing to fret about," the U.S. Food and Drug Administration told Science.
However, it should also be noted that the levels of radioactivity may have been higher, and potentially more hazardous to human health and other organisms, in the 1970s and '80s since radiocesium decays over time. The researchers want to use this study to highlight the long-term environmental impacts of pollutants since, while it can't be said for sure, cesium-137 might have had effects on the bee collapse and the decline of bee populations.