title: The concentration of iron in real-world geogenic PM₁₀ is associated with increased inflammation and deficits in lung function in mice.
abstract: BACKGROUND
  There are many communities around the world that are exposed to high levels of particulate matter <10 µm (PM₁₀) of geogenic (earth derived) origin. Mineral dusts in the occupational setting are associated with poor lung health, however very little is known about the impact of heterogeneous community derived particles. We have preliminary evidence to suggest that the concentration of iron (Fe) may be associated with the lung inflammatory response to geogenic PM₁₀. We aimed to determine which physico-chemical characteristics of community sampled geogenic PM₁₀ are associated with adverse lung responses.
  
  
  METHODS
  We collected geogenic PM₁₀ from four towns in the arid regions of Western Australia. Adult female BALB/c mice were exposed to 100 µg of particles and assessed for inflammatory and lung function responses 6 hours, 24 hours and 7 days post-exposure. We assessed the physico-chemical characteristics of the particles and correlated these with lung outcomes in the mice using principal components analysis and multivariate linear regression.
  
  
  RESULTS
  Geogenic particles induced an acute inflammatory response that peaked 6 hours post-exposure and a deficit in lung mechanics 7 days post-exposure. This deficit in lung mechanics was positively associated with the concentration of Fe and particle size variability and inversely associated with the concentration of Si.
  
  
  CONCLUSIONS
  The lung response to geogenic PM₁₀ is complex and highly dependent on the physico-chemical characteristics of the particles. In particular, the concentration of Fe in the particles may be a key indicator of the potential population health consequences for inhaling geogenic PM₁₀.
authors.affiliation: School of Medicine, University of Tasmania, Hobart, Tasmania, Australia ; Cooperative Research Centre for Asthma and Airways, Sydney, New South Wales, Australia.
authors.forename: Graeme R
authors.initials: GR
authors.lastname: Zosky
authors.affiliation: Telethon Institute for Child Health Research, Subiaco, Western Australia, Australia.
authors.forename: Thomas
authors.initials: T
authors.lastname: Iosifidis
authors.affiliation: Telethon Institute for Child Health Research, Subiaco, Western Australia, Australia.
authors.forename: Kara
authors.initials: K
authors.lastname: Perks
authors.affiliation: School of Paediatrics and Child Health, The University of Western Australia, Subiaco, Western Australia, Australia.
authors.forename: Will G F
authors.initials: WG
authors.lastname: Ditcham
authors.affiliation: School of Paediatrics and Child Health, The University of Western Australia, Subiaco, Western Australia, Australia.
authors.forename: Sunalene G
authors.initials: SG
authors.lastname: Devadason
authors.affiliation: Cooperative Research Centre for Asthma and Airways, Sydney, New South Wales, Australia ; School of Population Health, The University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: W Shan
authors.initials: WS
authors.lastname: Siah
authors.affiliation: Cooperative Research Centre for Asthma and Airways, Sydney, New South Wales, Australia ; School of Population Health, The University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: Brian
authors.initials: B
authors.lastname: Devine
authors.affiliation: Cooperative Research Centre for Asthma and Airways, Sydney, New South Wales, Australia ; School of Population Health, The University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: Fiona
authors.initials: F
authors.lastname: Maley
authors.affiliation: Cooperative Research Centre for Asthma and Airways, Sydney, New South Wales, Australia ; School of Population Health, The University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: Angus
authors.initials: A
authors.lastname: Cook
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity; D000704:Analysis of Variance; D000818:Animals; D016207:Cytokines / Q000378:metabolism; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D004784:Environmental Monitoring; D005260:Female; D005843:Geography; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D007501:Iron / Q000032:analysis* / Q000378:metabolism; D008807:Mice, Inbred BALB C; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity; D011014:Pneumonia / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology*; D012143:Respiratory Physiological Phenomena; D013997:Time Factors; D014904:Western Australia
chemical_list: D000393:Air Pollutants; D016207:Cytokines; D018836:Inflammation Mediators; D052638:Particulate Matter; D007501:Iron