Radar Magazine has a fantastic article listing what they believe to be the 12 most dangerous toys ever produced.
Pray for Coal:
The most dangerous toys of all time Here's a small example...
Kids do the darndest things, but not, apparently, nuclear physics. The toy was only sold for one year. It's unclear what effects the Uranium-bearing ores might have had on those few lucky children who received the set, but exposure to the same isotope-U-238-has been linked to Gulf War syndrome, cancer, leukemia, and lymphoma, among other serious ailments.