Along with snakes on a plane, a broken window or the engine giving way, the words “radioactive spill” are something no one wants to even imagine as something that could occur on a flight they happen to be on.

But given the fact that planes transport all kinds of cargo and even commercial flights cannot always know what travelers have in their suitcases, such incidents do (very rarely) occur — including earlier this week, on a Swiss Airlines flight from Zurich to Barcelona.

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As first reported by Catalan newspaper El Nacional, five cargo workers were rushed to the hospital after a suitcase containing “low-intensity radioactive material” was damaged while they were unloading the baggage after the plane landed in Barcelona. 

Suitcase damaged during plane’s unloading contained radioactive medicine, prompts terminal shutdown

The 130 passengers aboard the flight were held inside the plane at Barcelona-El Prat Airport for two hours as radiological experts examined the area and declared it safe to exit the plane. Along with the workers, a small number of passengers close to the affected area have also been held in isolation for several hours as a precaution before it was known how their exposure would affect others. 

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According to the report from Spain’s civil defense authorities, the material was a radioactive medicine used to treat certain types of cancer that a traveler was transporting from Switzerland to Salamanca in northern Spain.

The entire terminal was blocked off as 13 fire crews also arrived as a precaution. After examining the area, Spain’s Emergency Medical System said that “no assistance was needed” and that “no one was affected.” 

‘Ground staff noticed that a box containing radioactive material had damp patches…’

“The operations will be withdrawn and the Aerocat and Radcat plans are deactivated,” the civil defense agency said at 1:35 p.m. local time.

“We can confirm that during the unloading of the cargo hold of flight LX1952 in Barcelona, ground staff noticed that a box containing radioactive material had damp patches,” Swiss Airlines said in a statement on the incident to media outlets. “Following the necessary measurements, the responsible authorities did not detect any radioactive contamination.”

By 2 p.m. local time, the same plane was cleared to use for a return flight back to Zurich while none of the other flights out of Barcelona-El Prat Airport were affected by the terminal shutdown. 

Some of the flights coming in at the time authorities were responding to the spill were redirected to other sections of the airport.

While in this case the radioactive cargo was transported properly and ended up getting damaged at some point during the flight or when it was unloaded by accident, airports also have systems to detect radioactive material that is being transported illicitly by criminals transporting materials needed to make weapons or other illegal items — from doorways to the parts of the airport through which cargo moves before being loaded onto the plane or moved to other parts of the airport.

“Members of the public often don’t realize that some airports are able to detect even tiny amounts of radioactivity in buildings or cargo-processing areas,” Chris Baraniuk reported in an article on the subject.