Conditions Favoring the Occurrence of Ignis Fatuus Phenomenon Over a Mass Grave in Niepołomice (S Poland)

A phenomenon of glowing clouds occurred at the border of Puszcza Niepołomicka in the vicinity of Niepołomice near Craco. Especially at spring and autumn nights, The most plausible explanation includes oxidation of gaseous P–bearing compounds with formation of phosphine, diphosphine and hydrogen. In the environment of variable water conditions in Pleistocene sands bedded by Miocene clays, phosphorus contained in bone remnants of the mass grave in the form of calcium hydroxyapatite alters to phosphides in the subsoil to gaseous forms of phosphor hydrogen compounds. This phenomenon is favored by microorganisms, including those from human digestive system, slightly acidic reaction of the soil (pine tree needles), the presence of heavy elements in soil (also from ammunition cartridges), high relative moisture of the air at night and the presence of the inversion air layer.