About half a century ago, in the 1950s and 1960s, several countries around the world were engaged in nuclear testing, including the United States, Mexico, and others. Most of the detonations occurred over the Marshall Islands in the Pacific and Novaya Zemlya, an arctic archipelago in northern Russia. Other tests were also done in New Mexico and Nevada.
If we can accurately gauge that these Cold War events are behind us, the consequences would still have lingered, as a study by researchers at William & Mary University in Williamsburg, Virginia, shows. In fact, lead researcher Jim Kaste, an environmental geochemist at that university, already knew that the effects of the hundreds of nuclear weapons tested still remained in the atmosphere and the environment.
The radioactive effects of the Cold War are still present in our environment
Specifically, cesium-137, a radioactive isotope that is a by-product of nuclear fission resulting from the reaction of uranium and plutonium, traces of which remain in food due to nuclear contamination of the environment.
Jim Kaste, who is also a teacher, then decided in 2017 to demonstrate to his students the presence of these radioactive contaminants in the current environment. He therefore asks them to bring local food back to the places where they go on vacation. Students then brought back several samples of fruits, nuts, honey, and other foods.
The gamma detector showed that most of these foods only had very low traces of cesium-137. However, this was not the case with a jar of honey from the North Carolina farmers market.
Honey contains 100 times more cesium-137 than other foods
Even Jim Kaste hadn’t expected the numbers revealed by the detector. He said in a statement that he revised the measurements because he was thinking of an anomaly at the level of the container or its detector. Nevertheless, he then had to face the facts: the detector showed a cesium-137 times higher content than other foods.
The PRISCILLA event took place on June 24, 1957 at the Nevada Proving Grounds (37 kilotons). Photo credit: Wikipedia
To explain this high level of cesium-137, Kaste and his team tested 122 samples of raw, pure, and unfiltered honey. These honeys were made locally and came from various markets and beekeepers in the eastern United States. They found that 68 honey samples showed remarkable traces of cesium-137. According to the researchers, it is the cumulative effect of all detonations of the 20th century that could have released more ionizing radiation into the atmosphere than any other event in human history.
Fortunately, this radioactive isotope is no longer harmful to health.
In their study published in Nature Communications, the researchers found that “most atmospheric detonations were so powerful that dozens of radioactive fission products were injected into the stratosphere and dispersed around the world with a residence time of about a year, before precipitation deposited them the earth.
They add that “the presence of radioactive pollution from nuclear tests is ubiquitous around the world and is detectable on every continent and even in deep-sea trenches”. The good news is that while the cesium-137 content in honey is high, it is not harmful to humans. In fact, its radioactivity threshold is below 50 to 100 Becquerel per kilogram.
Even so, that was a different story, probably half a century ago. As Kaste says, “What we see today is a small fraction of the radiation that was there in the 60s and 70s. And we can’t say for sure whether cesium-137 had anything to do with the breakdown. Beehives or population decline. ” .