Open Access Open Badges Research article

A descriptive analysis of relations between parents' self-reported smoking behavior and infants' daily exposure to environmental tobacco smoke

Doris Kehl1*, Jochen R Thyrian2, Jan Lüdemann3, Matthias Nauck3 and Ulrich John4

Author Affiliations

1 Ernst-Moritz-Arndt-University Greifswald, Institute of Psychology, Department Health and Prevention, Robert-Blum-Str. 13, D-17487 Greifswald, Germany

2 Ernst-Moritz-Arndt-University Greifswald, Institute of Community Medicine, Section Epidemiology of Health Care and Community Health, Ellernholzstr. 1-2, D-17487 Greifswald, Germany

3 University Hospital Greifswald, AoR, Institute of Clinical Chemistry and Laboratory Medicine, Sauerbruchstrasse, D-17475 Greifswald, Germany

4 Ernst-Moritz-Arndt-University Greifswald, Institute of Epidemiology and Social Medicine, Walther-Rathenau-Str. 48, D-17487 Greifswald, Germany

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BMC Public Health 2010, 10:424  doi:10.1186/1471-2458-10-424

Published: 19 July 2010



The aims of the present study were to examine relations between parents' self-reported smoking behavior and infants' daily exposure to environmental tobacco smoke, as assessed by urinary cotinine-to-creatinine ratio (CCR), and to describe the CCR over seven days among infants at home.


A convenience sample of 27 households was drawn. Each household had to have at least one daily tobacco smoker and one child up to three years of age. Over a seven-day period, urine samples were obtained from the child daily. To examine relations between parents' self-reported smoking and infants' daily CCR, generalized estimating equation (GEE) analysis was used.


The data revealed that infants from households with indoor smoking had higher CCRs than infants in households with outdoor smoking. CCRs were higher in girls than in boys. Older infants had lower CCRs than younger infants. Smoking outside the home versus inside the home, infant's gender, and infants' age accounted for 68% of the variance in CCR in a GEE data analysis model. No increase or decrease of CCR over time was found.


The findings suggest that parents' self-reported smoking indoors at home versus outdoors is predictive of CCR among infants three and younger. Higher CCR concentrations in girls' urine need further examination. Furthermore, significant fluctuations in daily CCR were not apparent in infants over a seven-day time period.