title: Particle counting and microbiological air sampling: results of the simultaneous use of both procedures in different types of hospital rooms.
abstract: BACKGROUND
  In order to assess the relationship between the concentrations of airborne fungi and particles, particle counting was combined with fungal air sampling in several rooms of a hospital.
  
  
  METHODS
  Concentrations of ≥0.5μm particles (P05) and ≥1μm particles (P1) were measured using a particle counter; fungal air sampling was performed with volumetric air samplers, which impacted air on Rodac plates with Sabouraud chloramphenicol agar. Particle counts were categorised according to ISO 14644-1 standard cut-off points; their association with fungal detection was assessed with Fisher's exact test.
  
  
  RESULTS
  Forty-two simultaneous samplings were carried out: 24 in operating rooms, 13 in rooms for burns or haematology patients, 3 in pharmacy clean rooms, and two in other procedure rooms. Filamentous fungi were recovered in 5 samples, which also had higher particle counts. No fungi were detected in 12 samplings with both P05 and P1 concentrations below the maximum for class 6 clean rooms; 4 of 7 samplings with both concentrations within the range for class 8 clean rooms were positive for fungi. The association between fungal detection and higher particle counts was statistically significant, both for P05 (p=.004) and P1 (p=.003). There was a partial overlap between the concentrations of particles of samplings which were positive or negative for fungi.
  
  
  CONCLUSIONS
  There is a relationship between the concentrations of P05 and P1 and airborne fungi in hospital rooms. When both P05 and P1 concentrations are below the maximum for class 6 clean rooms, a negative fungal detection can be predicted.
authors.affiliation: Servicio de Medicina Preventiva y Epidemiología, Hospital Universitario Vall d'Hebron, Barcelona, Spain. larmadan@vhebron.net
authors.forename: Lluís
authors.initials: L
authors.lastname: Armadans-Gil
authors.forename: Virginia
authors.initials: V
authors.lastname: Rodríguez-Garrido
authors.forename: Magda
authors.initials: M
authors.lastname: Campins-Martí
authors.forename: Julita
authors.initials: J
authors.lastname: Gil-Cuesta
authors.forename: Josep
authors.initials: J
authors.lastname: Vaqué-Rafart
mesh_terms: D000336:Aerosols; D000391:Air Microbiology; D016902:Air Pollution, Indoor / Q000032:analysis*; D002053:Burn Units / Q000706:statistics & numerical data; D004780:Environment, Controlled; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D005658:Fungi / Q000302:isolation & purification*; D006405:Hematology; D006757:Hospital Units / Q000706:statistics & numerical data*; D009873:Operating Rooms / Q000706:statistics & numerical data*; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D010362:Patients' Rooms / Q000145:classification / Q000706:statistics & numerical data*; D010607:Pharmacy Service, Hospital; D013030:Spain; D013172:Spores, Fungal; D015003:Yeasts / Q000302:isolation & purification
chemical_list: D000336:Aerosols; D052638:Particulate Matter