Is radon involved in volcanic lightning?

Volcanoes, Lightning -?Radon?

This article in the New York Times discusses the discovery that even an ash-less volcano like Stromboli has a substantial charge. It was thought that charges (and hence lightning) in a volcanic ash cloud was caused by the particles rubbing against each other. 

But balloons sent over Stromboli (by a Bristol University physicist) discovered electrical charges in its cloud. The source of the charge is thought to be the decay of radioactive radon!

By itself radon does not seem to cause lightning - no lightning at Stromboli - but more work will be done to examine its contribution.

An eruption of the Calbuco volcano in April 2015. Martin Bernetti/Agence France-Presse — Getty Images