title: Preschool children and their mothers are more exposed to paternal smoking at home than school children and their mothers.
abstract: BACKGROUND
  Exposure to secondhand smoke (SHS) is a major risk to human health, and the home is the greatest single source of SHS in children. Here, the authors assessed SHS exposure of children and mothers by paternal smoking at home, and investigated how different this exposure is according to smoking location and children's age.
  
  
  METHODS
  Two hundred-five families were enrolled in this study as trios of fathers, mothers, and children. Nicotine concentrations in hair were measured using liquid chromatography-tandem mass spectrometry to determine long-term exposure to SHS.
  
  
  RESULTS
  Differences between the smoker group and nonsmoker group in nicotine levels were statistically significant in both children and their mothers. However, difference between the indoor-smoker group and outdoor-smoker group was marginally significant in children and was not significant in their mothers. In the indoor-smoker group, preschool children and their mothers had nicotine concentrations about twice as high as school children and their mothers, respectively. In the outdoor-smoker group, however, differences between two age groups in nicotine levels were significant in preschool children, but not their mothers.
  
  
  CONCLUSIONS
  These findings indicate that paternal smoking at home leads to significant exposure to SHS in their children and spouses, which is not completely prevented by smoking outside. Especially, preschool children and their mothers appear to be most at risk for SHS exposure among nonsmoking household members.
authors.affiliation: Department of Laboratory Medicine, National Cancer Center Hospital, Goyang, Republic of Korea.
authors.forename: Moon-Woo
authors.initials: MW
authors.lastname: Seong
authors.forename: Jin Soo
authors.initials: JS
authors.lastname: Moon
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Hwang
authors.forename: Hye-Jung
authors.initials: HJ
authors.lastname: Ryu
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Kang
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Kong
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Um
authors.forename: Jae-Gahb
authors.initials: JG
authors.lastname: Park
authors.forename: Jin Soo
authors.initials: JS
authors.lastname: Lee
authors.forename: Do-Hoon
authors.initials: DH
authors.lastname: Lee
mesh_terms: D000328:Adult; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D003367:Cotinine / Q000032:analysis; D004781:Environmental Exposure; D005220:Fathers; D005260:Female; D006197:Hair / Q000737:chemistry; D006801:Humans; D009538:Nicotine / Q000032:analysis; D011247:Pregnancy; D012907:Smoking; D011795:Surveys and Questionnaires; D053719:Tandem Mass Spectrometry
chemical_list: D009538:Nicotine; D003367:Cotinine