222Rn decays to 218Po (half-life 3.10 minutes). The remaining elements in the decay chain are bismuth and thallium, ultimately ending in 206Pb.

Number 7 in the above-linked list, lead-210, is the interesting one. Its 22-year half-life means gas and LPG plumbing accumulate it. Each second about one in a billion of its atoms turns into 210-Bi, and that, within days, turns into 210-Po. 210-Po is also known as Litvinenko's bane.

--- G.R.L. Cowan (How fire can be domesticated)

And, once plated out on the plumbing (which it is likely to do as soon as it becomes 218Po), it is very unlikely to ever wind up at the burner tip and bother anyone.