[Wonder Warthog]

"Further investigation yielded the information that the swing set had been manufactured out of recycled dental office X-ray machines."

Nope, 'fraid not. Dental x-ray machines use x-ray tubes to generate x-rays. No radioisotopes involved, nor any radioactivity generated. The culprits were pipeline weld inspection sources, which use gamma rays (not x-rays), and contain cobalt-60 or cesium-137 radioisotopes. As I recall, they had been stolen and sold as "scrap metal" in Mexico.

[thecodont]

The culprits were pipeline weld inspection sources, which use gamma rays (not x-rays), and contain cobalt-60 or cesium-137 radioisotopes. As I recall, they had been stolen and sold as "scrap metal" in Mexico.

I don't have a link to the story (I'll try to find it) but I do remember that cobalt-60 was mentioned.