title: Effects of Eyjafjallajökull volcanic ash on innate immune system responses and bacterial growth in vitro.
abstract: BACKGROUND
  On 20 March 2010, the Icelandic volcano Eyjafjallajökull erupted for the first time in 190 years. Despite many epidemiological reports showing effects of volcanic ash on the respiratory system, there are limited data evaluating cellular mechanisms involved in the response to ash. Epidemiological studies have observed an increase in respiratory infections in subjects and populations exposed to volcanic eruptions.
  
  
  METHODS
  We physicochemically characterized volcanic ash, finding various sizes of particles, as well as the presence of several transition metals, including iron. We examined the effect of Eyjafjallajökull ash on primary rat alveolar epithelial cells and human airway epithelial cells (20-100 µg/cm(2)), primary rat and human alveolar macrophages (5-20 µg/cm(2)), and Pseudomonas aeruginosa (PAO1) growth (3 µg/104 bacteria).
  
  
  RESULTS
  Volcanic ash had minimal effect on alveolar and airway epithelial cell integrity. In alveolar macrophages, volcanic ash disrupted pathogen-killing and inflammatory responses. In in vitro bacterial growth models, volcanic ash increased bacterial replication and decreased bacterial killing by antimicrobial peptides.
  
  
  CONCLUSIONS
  These results provide potential biological plausibility for epidemiological data that show an association between air pollution exposure and the development of respiratory infections. These data suggest that volcanic ash exposure, while not seriously compromising lung cell function, may be able to impair innate immunity responses in exposed individuals.
authors.affiliation: Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
authors.forename: Martha M
authors.initials: MM
authors.lastname: Monick
authors.forename: Jonas
authors.initials: J
authors.lastname: Baltrusaitis
authors.forename: Linda S
authors.initials: LS
authors.lastname: Powers
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Borcherding
authors.forename: Juan C
authors.initials: JC
authors.lastname: Caraballo
authors.forename: Imali
authors.initials: I
authors.lastname: Mudunkotuwa
authors.forename: David W
authors.initials: DW
authors.lastname: Peate
authors.forename: Katherine
authors.initials: K
authors.lastname: Walters
authors.forename: Jay M
authors.initials: JM
authors.lastname: Thompson
authors.forename: Vicki H
authors.initials: VH
authors.lastname: Grassian
authors.forename: Gunnar
authors.initials: G
authors.lastname: Gudmundsson
authors.forename: Alejandro P
authors.initials: AP
authors.lastname: Comellas
mesh_terms: D000328:Adult; D000818:Animals; D001343:Autophagy; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development*; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007055:Iceland; D007113:Immunity, Innate; D020935:MAP Kinase Signaling System; D008264:Macrophages / Q000276:immunology; D008297:Male; D050296:Microbial Viability / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D018707:Volcanic Eruptions / Q000009:adverse effects*; D023083:beta-Defensins / Q000494:pharmacology
chemical_list: D023083:beta-Defensins