Assessment of environmental tobacco smoke exposure in children with asthmatic symptoms by questionnaire and cotinine concentrations in plasma, saliva, and urine
To validate a detailed questionnaire for assessment of environmental tobacco smoke (ETS) exposure by the biomarker cotinine in various media, a population-based study in the urban area of Malmo, Sweden was performed in children aged 8-13 years with and without asthmatic symptoms. There were strong correlations between urinary and saliva cotinine concentrations and also, though to a lesser extent,