I’m surprised you know this but didn’t think further about the situation.
Where was anericum used in smoke detectors, and was there perhaps some other region where plutonium was used?
Perhaps somewhere colder, more, soviet-ey?
back in the 50s "fire" detectors had a block of uranium and a vacuum tube to detect smoke or ionized combustive particles
I don't have much knowledge of soviet society, that's why. Just their cavalier attitude to nuclear safety.
Though to be fair, America wasn't much better in the 50s. Nor was Britain if you read about the "procedures" surrounding the windscale meltdown. Uranium rods would get stuck and people would just poke it with a stick.