Objectively measured secondhand smoke exposure and mental health in children: evidence from the Scottish Health Survey.
OBJECTIVE
To examine the association between objectively assessed secondhand smoke (SHS) exposure and mental health in a representative sample of British children.


METHODS
Cross-sectional study.


METHODS
Community-based population sample from the 2003 Scottish Health Survey.


METHODS
Nine hundred one nonsmoking children (mean [SD] age, 8.3 [2.5] years).


METHODS
Exposure to SHS was determined from salivary cotinine level and self-report.


METHODS
Psychological distress assessed using the Strengths and Difficulties Questionnaire (SDQ).


RESULTS
Forty percent of the sample demonstrated high SHS exposure (cotinine level >0.70 ng/mL). Children with higher cotinine levels were more likely to live in areas of greater socioeconomic deprivation. Participants in the highest cotinine quartile (>0.70 ng/mL) had significantly higher total SDQ scores compared with those in the lowest quartile (age- and sex-adjusted mean difference = 2.8; 95% confidence interval, 1.6 to 3.9). There was evidence of a dose-response effect across the cotinine group (P trend = .001). Of the SDQ subscales, the strongest associations with cotinine levels emerged for hyperactivity and conduct disorder. These associations remained statistically significant after adjustment for possible confounders including social deprivation, single-parent status, body mass index, chronic illness, and physical activity.


CONCLUSIONS
Objectively assessed SHS exposure was associated with poorer mental health among children.
Department of Epidemiology and Public Health, University College London, London, England. m.hamer@ucl.ac.uk
Mark
M
Hamer
Tamsin
T
Ford
Emmanuel
E
Stamatakis
Samantha
S
Dockray
G David
GD
Batty
D000367:Age Factors; D002648:Child; D015331:Cohort Studies; D003367:Cotinine / Q000378:metabolism; D003430:Cross-Sectional Studies; D004781:Environmental Exposure; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000378:metabolism; D012307:Risk Factors; D012606:Scotland; D014028:Tobacco Smoke Pollution
D014028:Tobacco Smoke Pollution; D003367:Cotinine