TY - JOUR T1 - <em>To the Editors:</em> JF - European Respiratory Journal JO - Eur Respir J SP - 226 LP - 227 DO - 10.1183/09031936.00159909 VL - 35 IS - 1 AU - J. D. Brain AU - W. Kreyling AU - P. Gehr Y1 - 2010/01/01 UR - http://erj.ersjournals.com/content/35/1/226.abstract N2 - We are writing to express concern about the recent paper by Song et al. 1, which was published in a recent issue of the European Respiratory Journal. We read the paper with great interest, as it would constitute the first report of human nanoparticle-related disease and death. The title attracted our attention, as well as that of the international media: “Exposure to nanoparticles is related to pleural effusion, pulmonary fibrosis and granuloma.” Note the use of the word “is.” The title appears to state a fact. We object. We write as individuals committed to the science of nanotoxicology. It is known that nanomaterials have unusual physical and chemical properties 2 and that these unusual characteristics, combined with the ever expanding use of nanomaterials, deserve careful investigation 3 … ER -