title: Factors influencing exposure to secondhand smoke in preschool children living with smoking mothers.
abstract: BACKGROUND
  The health effects on young children of exposure to secondhand smoke (SHS) are well described. Recent work suggests that over one quarter of school-aged children in Scotland are regularly exposed to SHS in the home. The study was designed to describe SHS exposure in preschool children whose mothers smoked and identify factors that influence exposure.
  
  
  METHODS
  Smoking mothers with at least one child aged 1-5 years were recruited to the Reducing Families' Exposure to Secondhand Smoke in the Home study. Concentrations of airborne particulate matter less than 2.5 μm in size (PM(2.5)) in the home were measured together with child's salivary cotinine. Demographics including age, accommodation type, socioeconomic status, and number of cigarettes smoked at home were recorded.
  
  
  RESULTS
  Data were collected from 54 homes. In 89% of the homes, concentrations of PM(2.5) exceeded health-based guidance values at some point of the day. Household PM(2.5) concentrations were highest during the evening hours of 6 p.m. to midnight. Younger children had higher salivary cotinine concentrations than older children, and the geometric mean of salivary cotinine was 2.36 ng/ml. Household smoking restrictions and maternal confidence in enforcing smoking restrictions in their own home were strongly associated with child's SHS exposure.
  
  
  CONCLUSIONS
  Preschool children's exposure to SHS in homes where the mother smokes is considerable. Interventions and policy development to increase parental awareness of the health effects of SHS and provide parents with the confidence to implement smoke-free households are required to reduce the SHS exposure of preschool age children.
authors.affiliation: Division of Applied Health Sciences, Scottish Centre for Indoor Air, University of Aberdeen, Aberdeen, United Kingdom.
authors.forename: Lynsey M
authors.initials: LM
authors.lastname: Mills
authors.forename: Sean E
authors.initials: SE
authors.lastname: Semple
authors.forename: Inga S
authors.initials: IS
authors.lastname: Wilson
authors.forename: Laura
authors.initials: L
authors.lastname: MacCalman
authors.forename: Amanda
authors.initials: A
authors.lastname: Amos
authors.forename: Deborah
authors.initials: D
authors.lastname: Ritchie
authors.forename: Rachel
authors.initials: R
authors.lastname: O'Donnell
authors.forename: April
authors.initials: A
authors.lastname: Shaw
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Turner
mesh_terms: D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000032:analysis*; D002675:Child, Preschool; D003367:Cotinine / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D008875:Middle Aged; D009035:Mothers; D012463:Saliva / Q000737:chemistry*; D012606:Scotland; D012907:Smoking / Q000503:physiopathology*; D000074606:Smoking Prevention; D014028:Tobacco Smoke Pollution / Q000032:analysis*; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D014028:Tobacco Smoke Pollution; D003367:Cotinine