A WC-135 in air.
A WC-135 in air. U.S. Air Force/Public Domain

A week and a half ago, the Institut de Radioprotection et de Sûreté Nucléaire (IRSN), a French agency tasked with investigating nuclear threats, issued a cryptic press release on its website. 

A spike in iodine-131, an isotope that is a product of nuclear fission (like, for instance, after the explosion of a nuclear bomb), had been detected across Europe, IRSN said.

The isotope, which has medical uses but can also be very dangerous, had been detected “in tiny amounts in the ground-level atmosphere in Europe,” the agency said, in countries from Norway to Spain. 

They also produced a scary-looking map: 

And then, four days later, The Aviationist reported that an American plane, the WC-135 Constant Phoenix, also known as a nuclear “sniffer” for its ability to detect and analyze fallout residue, had been deployed to Britain, possibly—officials didn’t say—to aid in investigating the reported iodine-131 spike. 

Yet, a few days after that report, the Comprehensive Nuclear-Test-Ban Treaty Organization, or the CTBTO, an international organization established by the (still not ratified) Comprehensive Nuclear Test-Ban Treaty, said, no, levels of iodine-131 were normal across Europe, or at least compared to what they have been historically. 

The CTBTO also noted that had there been a secret nuclear test, perhaps by Russia, as many had been speculating, we would’ve seen higher levels of not just iodine-131, but a range of nuclear fission products. 

Finally, yesterday, The Aviationist reported that the American nuclear sniffer had taken off, en route, apparently, for Norway, its mission still unknown. An Air Force spokesman told The Independent that the plane was merely in Europe for a “a preplanned rotational deployment scheduled far in advance.”

So what’s going on here? 

Probably not a secret nuclear test, for one thing. As the CTBTO notes, if that were the case, a lot more than just higher levels of iodine-131 would show up.

An accidental leak from a pharmaceutical or medical facility, however, is one possibility, as is some kind of release from a nuclear submarine, Russian or otherwise. 

But the strongest possibility remains: nothing. Ever since iodine-131 was discovered in 1938, we’ve used it for a wide range of things, like fighting thyroid cancer, which means that it’s ever present in labs and hospitals and other places across the globe. 

It’s also, as the CTBTO says, detected at trace levels “across the world,” meaning that this minor spike, if it even exists, wouldn’t be much of a threat, since we are already coexisting with it, whether you realize it or not.