title: Calculation of hygroscopic particle deposition in the human lung.
abstract: BACKGROUND
  Inhaled hygroscopic aerosols will absorb water vapor from the warm and humid air of the human lung, thus growing in size and consequently changing their deposition properties.
  
  
  OBJECTIVE
  The objectives of the present study are to study the effect of a stochastic lung structure on individual particle growth and related deposition patterns and to predict local deposition patterns for different hygroscopic aerosols.
  
  
  METHODS
  The hygroscopic particle growth model proposed by Ferron et al. has been implemented into the stochastic asymmetric lung deposition model IDEAL. Deposition patterns were calculated for sodium chloride (NaCl), cobalt chloride (CoCl2 · 6H2O), and zinc sulfate (ZnSO4 · 7H2O) aerosols, representing high, medium and low hygroscopic growth factors.
  
  
  RESULTS
  Hygroscopic growth decreases deposition of submicron particles compared to hydrophobic particles with equivalent diameters due to a less efficient diffusion mechanism, while the more efficient impaction and sedimentation mechanisms increase total deposition for micron-sized particles. Due to the variability and asymmetry of the human airway system, individual trajectories of inhaled particles are associated with individual growth factors, thereby enhancing the variability of the resulting deposition patterns.
  
  
  CONCLUSIONS
  Comparisons of model predictions with several experimental data for ultrafine and micrometer-sized particles indicate good agreement, considering intersubject variations of morphometric parameters as well as differences between experimental conditions and modeling assumptions.
authors: Division of Physics and Biophysics, Department of Materials Research and Physics, University of Salzburg , Salzburg , Austria and.
authors: Renate
authors: R
authors: Winkler-Heil
authors: George
authors: G
authors: Ferron
authors: Werner
authors: W
authors: Hofmann
mesh_terms: D000042:Absorption; D000336:Aerosols; D000393:Air Pollutants / Q000493:pharmacokinetics* / Q000633:toxicity; D003035:Cobalt / Q000493:pharmacokinetics / Q000633:toxicity; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008954:Models, Biological; D052638:Particulate Matter / Q000493:pharmacokinetics* / Q000633:toxicity; D012965:Sodium Chloride / Q000493:pharmacokinetics / Q000633:toxicity; D013269:Stochastic Processes; D014018:Tissue Distribution; D014867:Water / Q000737:chemistry; D019287:Zinc Sulfate / Q000493:pharmacokinetics / Q000633:toxicity
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter; D014867:Water; D003035:Cobalt; D012965:Sodium Chloride; D019287:Zinc Sulfate; C018021:cobaltous chloride