title: Secondhand smoke levels in public building main entrances: outdoor and indoor PM2.5 assessment.
abstract: OBJECTIVE
  To describe secondhand smoke (SHS) levels in halls and main entrances (outdoors) in different buildings by measurement of PM(2.5) and airborne nicotine.
  
  
  METHODS
  Cross-sectional study in a sample of 47 public buildings. The authors studied SHS levels derived from PM(2.5) (micrograms per cubic metre) using TSI SidePak Personal Aerosol Monitors. The authors tested four locations within buildings: hall, main entrance (outdoor), control (indoor) and control (outdoor). The authors also measured airborne nicotine concentration (micrograms per cubic metre) in main entrances (outdoor). The authors computed medians and IQRs to describe the data. Spearman correlation coefficient (rsp) was used to explore the association between PM(2.5) concentrations simultaneously measured in halls and main entrances as well as between PM(2.5) and nicotine concentrations.
  
  
  RESULTS
  The authors obtained an overall median PM(2.5) concentration of hall 18.20 μg/m(3) (IQR: 10.92-23.92 μg/m(3)), main entrance (outdoor) 17.16 μg/m(3) (IQR: 10.92-24.96 μg/m(3)), control (indoor) 10.40 μg/m(3) (IQR: 6.76-15.60 μg/m(3)) and control (outdoor) 13.00 μg/m(3) (IQR: 8.32-18.72 μg/m(3)). The PM(2.5) concentration in halls was more correlated with concentration in the main entrances (outdoors) (rsp=0.518, 95% CI 0.271 to 0.701) than with the control indoor (rsp=0.316, 95% CI 0.032 to 0.553). The Spearman correlation coefficient between nicotine and PM(2.5) concentration was 0.365 (95% CI -0.009 to 0.650).
  
  
  CONCLUSIONS
  Indoor locations where smoking is banned are not completely free from SHS with levels similar to those obtained in the immediate entrances (outdoors) where smoking is allowed, indicating that SHS from outdoors settings drifts to adjacent indoors. These results warrant a revision of current smoke-free policies in particular outdoor settings.
authors.affiliation: Tobacco Control Unit, Cancer Prevention and Control Programme, Institut Català d'Oncologia-ICO, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Xisca
authors.initials: X
authors.lastname: Sureda
authors.forename: Jose M
authors.initials: JM
authors.lastname: Martínez-Sánchez
authors.forename: María José
authors.initials: MJ
authors.lastname: López
authors.forename: Marcela
authors.initials: M
authors.lastname: Fu
authors.forename: Fernando
authors.initials: F
authors.lastname: Agüero
authors.forename: Esteve
authors.initials: E
authors.lastname: Saltó
authors.forename: Manel
authors.initials: M
authors.lastname: Nebot
authors.forename: Esteve
authors.initials: E
authors.lastname: Fernández
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D003430:Cross-Sectional Studies; D004784:Environmental Monitoring / Q000379:methods; D006801:Humans; D009538:Nicotine / Q000032:analysis*; D010316:Particle Size; D018709:Statistics, Nonparametric; D014028:Tobacco Smoke Pollution / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D014028:Tobacco Smoke Pollution; D009538:Nicotine