We have previously discussed the worst examples of atomic quackery, or the false promise of radioactivity as a universal cure for all kinds of conditions. However, this widespread lie also managed to reach the world of cars: in the early 1940s, Firestone launched a series of “radioactive spark plugs” with polonium in their electrodes. Advertisements about a “smoother ride” and lower fuel consumption soon appeared...
To understand the origin of these radioactive spark plugs we must travel back about a hundred years. On May 24, 1922, inventor Grover R. Greenslade (not “Geover” as appears in other texts) described in his patent (US1523013A) the possibility of using radium, uranium, thorium, actinium, polonium or “any other radioactive substance” to optimize the electrodes. Two years later, inventor Alfred Hubbard followed a similar direction in his patent (US1723422A), although he mentions radium (technically “sulfite of radium and zinc”) as the ideal material to “ionize the space” between the terminals.
Firestone Spark Plugs: Polonium to Supercharge Your Spark Plugs
The folks at Firestone Tire and Rubber entered the scene much later, in December 1939 to be precise, with a patent (US2254169A) associated with John H. Dillon. One of the most notable aspects of that text is that it completely discards the use of radium (too costly and dangerous), uranium and thorium (low effectiveness), favoring the application of polonium (the word “polonium” is repeated more than 60 times in the patent).
The information loses some consistency at this point, but the Museum of Radiation and Radioactivity indicates that the official advertising for the spark plugs extended from 1940 to 1953. The only “media” backing they received came through the “November 1941” edition of Science Digest, reporting that their vehicle needed “30 percent fewer revolutions” to start the engine. In practice, it's most likely that any perceived benefit was linked to the very act of changing the spark plugs (clean and new, without deposits). As if that weren't enough, the effects of polonium were doomed from the start: with a half-life of 138.3 days for its isotope 210 (the most abundant, out of a total of 42), polonium becomes lead-206.
Source: Museum of Radiation and Radioactivity
