Dear Jan Panteltje:

On Wednesday, December 19, 2018 at 1:55:12 PM UTC-7, Jan Panteltje wrote:
....
We had some Chernobyl fallout here too, you were not
supposed to eat vegetables from your garden,
where I worked the air conditioning filters were hot
and had to be replaced.
....
Fun :-)

There have been cases where recently-retired dehumidifiers had to be held in storage for a few months, because the radon they had recycled, had decayed into metals that were embedded on their surfaces. Those had to be allowed to decay down enough to dispose of as simple waste.

David A. Smith