title: Legislation reduces exposure to second-hand tobacco smoke in New Zealand bars by about 90%.
abstract: OBJECTIVE
  To measure exposure to second-hand smoke (SHS) in New Zealand bars before and after comprehensive smoke-free legislation enacted on 10 December 2004.
  
  
  METHODS
  Cotinine is the main specific metabolite of nicotine and a well-established biomarker for SHS exposure. We measured cotinine levels in saliva of non-smoking volunteers before and after a 3 h visit to 30 randomly selected bars in 3 cities across the country. Two measures of cotinine before the smoke-free law change during winter and spring 2004, and two follow-up measurements in the same volunteers and venues during winter and spring 2005, were included.
  
  
  RESULTS
  Before the smoke-free law change, in all bars and in all volunteers, exposure to SHS was evident with an average increase in saliva cotinine of 0.66 ng/ml (SE 0.03 ng/ml). Increases in cotinine correlated strongly with the volunteers' subjective observation of ventilation, air quality and counts of lit cigarettes. However, even venues that were judged to be "seemingly smoke free" with "good ventilation" produced discernable levels of SHS exposure. After the law change, there remained some exposure to SHS, but at much lower levels (mean saliva cotinine increase of 0.08 ng/ml, SE 0.01 ng/ml). Smoking indoors in bars was almost totally eliminated: in 2005 only one lit cigarette was observed in 30 visits.
  
  
  CONCLUSIONS
  Comprehensive smoke-free legislation in New Zealand seems to have reduced exposure of bar patrons to SHS by about 90%. Residual exposures to SHS in bars do not result from illicit smoking indoors.
authors.affiliation: Institute of Environmental Science and Research, Wellington, New Zealand.
authors.forename: Dinusha
authors.initials: D
authors.lastname: Fernando
authors.forename: Jefferson
authors.initials: J
authors.lastname: Fowles
authors.forename: Alistair
authors.initials: A
authors.lastname: Woodward
authors.forename: Annemarie
authors.initials: A
authors.lastname: Christophersen
authors.forename: Stuart
authors.initials: S
authors.lastname: Dickson
authors.forename: Matthew
authors.initials: M
authors.lastname: Hosking
authors.forename: Richard
authors.initials: R
authors.lastname: Berezowski
authors.forename: Rod A
authors.initials: RA
authors.lastname: Lea
mesh_terms: D000328:Adult; D016902:Air Pollution, Indoor / Q000032:analysis / Q000331:legislation & jurisprudence* / Q000517:prevention & control; D003367:Cotinine / Q000032:analysis; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D012463:Saliva / Q000737:chemistry; D012907:Smoking / Q000331:legislation & jurisprudence; D000074606:Smoking Prevention; D014028:Tobacco Smoke Pollution / Q000032:analysis / Q000331:legislation & jurisprudence* / Q000517:prevention & control; D014691:Ventilation
chemical_list: D014028:Tobacco Smoke Pollution; D003367:Cotinine