title: Smoking, secondhand smoke, and cotinine levels in a subset of EPIC cohort.
abstract: BACKGROUND
  Several countries are discussing new legislation regarding the ban on smoking in public places, based on the growing evidence of the hazards of secondhand smoke (SHS) exposure. The objective of the present study is to quantitatively assess the relationship between smoking, SHS, and serum cotinine levels in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.
  
  
  METHODS
  From a study on lung cancer in the EPIC cohort, questionnaire information on smoking was collected at enrolment, and cotinine was measured in serum. Three statistical models were applied by using samples available in a cross-section design: (i) cotinine levels by categories combining smoking and SHS (n = 859); (ii) the effect of hours of passive smoking exposure in nonsmokers only (n = 107); (iii) the effect of the number of cigarettes consumed per day in current smokers only (n = 832). All models were adjusted for country, sex, age, and body mass index.
  
  
  RESULTS
  Among nonsmokers, passive smokers presented significant differences in cotinine compared with nonexposed, with a marked (but not significant) difference among former-smokers. A one hour per day increment of SHS gave rise to a significant 2.58 nmol/L (0.45 ng/mL) increase in mean serum cotinine (P < 0.001). In current smokers, a one cigarette per day increment gave rise to a significant 22.44 nmol/L (3.95 ng/mL) increase in cotinine mean (P < 0.001).
  
  
  CONCLUSIONS
  There is clear evidence that not only tobacco smoking but also involuntary exposure increases cotinine levels.
  
  
  CONCLUSIONS
  This study strengthens the evidence for the benefits of a smoking ban in public places.
authors.affiliation: Department of Epidemiology, School of Public Health, University of São Paulo, São Paulo, Brazil. vbaltar@usp.br
authors.forename: Valéria Troncoso
authors.initials: VT
authors.lastname: Baltar
authors.forename: Wei W
authors.initials: WW
authors.lastname: Xun
authors.forename: Shu-Chun
authors.initials: SC
authors.lastname: Chuang
authors.forename: Caroline
authors.initials: C
authors.lastname: Relton
authors.forename: Per Magne
authors.initials: PM
authors.lastname: Ueland
authors.forename: Stein Emil
authors.initials: SE
authors.lastname: Vollset
authors.forename: Øivind
authors.initials: Ø
authors.lastname: Midttun
authors.forename: Mattias
authors.initials: M
authors.lastname: Johansson
authors.forename: Nadia
authors.initials: N
authors.lastname: Slimani
authors.forename: Mazda
authors.initials: M
authors.lastname: Jenab
authors.forename: Françoise
authors.initials: F
authors.lastname: Clavel-Chapelon
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Boutron-Ruault
authors.forename: Guy
authors.initials: G
authors.lastname: Fagherazzi
authors.forename: Rudolf
authors.initials: R
authors.lastname: Kaaks
authors.forename: Sabine
authors.initials: S
authors.lastname: Rohrmann
authors.forename: Heiner
authors.initials: H
authors.lastname: Boeing
authors.forename: Cornelia
authors.initials: C
authors.lastname: Weikert
authors.forename: H Bas
authors.initials: HB
authors.lastname: Bueno-de-Mesquita
authors.forename: Hendriek C
authors.initials: HC
authors.lastname: Boshuizen
authors.forename: Carla H
authors.initials: CH
authors.lastname: van Gils
authors.forename: Petra H M
authors.initials: PH
authors.lastname: Peeters
authors.forename: Antonio
authors.initials: A
authors.lastname: Agudo
authors.forename: Aurelio
authors.initials: A
authors.lastname: Barricarte
authors.forename: Carmen
authors.initials: C
authors.lastname: Navarro
authors.forename: Laudina
authors.initials: L
authors.lastname: Rodríguez
authors.forename: José Maria Huerta
authors.initials: JM
authors.lastname: Castaño
authors.forename: Nerea
authors.initials: N
authors.lastname: Larrañaga
authors.forename: Maria José Sánchez
authors.initials: MJ
authors.lastname: Pérez
authors.forename: Kay-Tee
authors.initials: KT
authors.lastname: Khaw
authors.forename: Nick
authors.initials: N
authors.lastname: Wareham
authors.forename: Naomi E
authors.initials: NE
authors.lastname: Allen
authors.forename: Francesca
authors.initials: F
authors.lastname: Crowe
authors.forename: Valentina
authors.initials: V
authors.lastname: Gallo
authors.forename: Teresa
authors.initials: T
authors.lastname: Norat
authors.forename: Giovanna
authors.initials: G
authors.lastname: Tagliabue
authors.forename: Giovanna
authors.initials: G
authors.lastname: Masala
authors.forename: Salvatore
authors.initials: S
authors.lastname: Panico
authors.forename: Carlota
authors.initials: C
authors.lastname: Sacerdote
authors.forename: Rosario
authors.initials: R
authors.lastname: Tumino
authors.forename: Antonia
authors.initials: A
authors.lastname: Trichopoulou
authors.forename: Pagona
authors.initials: P
authors.lastname: Lagiou
authors.forename: Christina
authors.initials: C
authors.lastname: Bamia
authors.forename: Torgny
authors.initials: T
authors.lastname: Rasmuson
authors.forename: Göran
authors.initials: G
authors.lastname: Hallmans
authors.forename: Nina
authors.initials: N
authors.lastname: Roswall
authors.forename: Anne
authors.initials: A
authors.lastname: Tjønneland
authors.forename: Elio
authors.initials: E
authors.lastname: Riboli
authors.forename: Paul
authors.initials: P
authors.lastname: Brennan
authors.forename: Paolo
authors.initials: P
authors.lastname: Vineis
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D003367:Cotinine / Q000097:blood*; D003430:Cross-Sectional Studies; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012907:Smoking / Q000009:adverse effects*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D044465:White People
chemical_list: D014028:Tobacco Smoke Pollution; D003367:Cotinine