Lesser known fact. Most homes contain alpha radiation sources through their use in smoke detectors. http://www.epa.gov/radiation/sources/smoke_alarm.html

That being said, radiological material regulations are very strict these day. Back when I was working at a lab at school, I had to go through several days of safety courses before I could even be in the same room as some very weak alpha particle sources. The work I was doing did not utilize them, and the whole time the sources were locked in a cabinet.

It amazes me that this playset contained beta and gamma sources. Hopefully they were extremely weak; but still the radiation accumulates. (alpha particle sources are really only dangerous if ingested or inhaled, since outside the body, air shields against them)