Yttrium and lanthanides in human lung fluids, probing the exposure to atmospheric fallout

Inhalation of airborne particles can produce crystallization of phosphatic microcrysts in intraaveolarareas of lungs, sometimes degenerating into pulmonary fibrosis. Results of this study indicate that thesepathologies are induced by interactions between lung fluids and inhaled atmospheric dust in peopleexposed to volcanic dust ejected from Mount Etna in 2001. Here, the lung solid–liquid interaction isevaluated by the distribution of yttrium and lanthanides (YLn) in fluid bronchoalveolar lavages on selectedindividuals according the classical geochemical approaches. We found that shale-normalised patterns ofyttrium and lanthanides have a ‘V shaped’ feature corresponding to the depletion of elements from Ndto Tb when compared to the variable enrichments of heavy lanthanides, Y, La and Ce. These features andconcurrent thermodynamic simulations suggest that phosphate precipitation can occur in lungs due tointeractions between volcanic particles and fluids. We propose that patterns of yttrium and lanthanidescan represent a viable explanation of some pathology observed in patients after prolonged exposureto atmospheric fallout and are suitable to become a diagnostic parameter of chemical environmentalstresses.