Urinary cotinine and exposure to passive smoke in children and adolescents in Germany – Human biomonitoring results of the German Environmental Survey 2014–2017 (GerES V)

Passive smoking is a preventable and significant cause of many serious health problems, with children being particularly at risk. In the fifth German Environmental Survey (GerES V), conducted from 2014 to 2017, information reflecting the extent of passive smoke exposure in children and adolescents was collected by interview-based questionnaires and human biomonitoring (HBM) analyses of cotinine in urine from 2260 participants, aged 3-17 years. Based on these population-representative data, we describe current passive smoke exposure stratified by different subgroups and identify specific exposure determinants using multivariate logistic regression. The questionnaire data revealed that 42% of children and adolescents lived with at least one smoker in the household. Quantifiable concentrations of cotinine could be detected in 56% of the participants. The overall median concentration of cotinine was 0.2 μg/L, with children and adolescents of low socioeconomic status found to be a group particularly affected by passive smoke with higher cotinine concentrations (median = 1.2 μg/L). In the multiple analysis, the most significant predictor of cotinine levels derived from the questionnaire was passive smoking at home (odds ratio (OR) 13.07 [95CI: 4.65, 36.70]). However, parental smoking and passive smoking among friends and relatives could also be identified as independent factors influencing elevated cotinine levels. The comparison between the previous cycle GerES IV (2003-2006) on 3-14-year-olds and GerES V shows that tobacco smoke exposure of children decreased significantly. This decrease is likely an effect of extensive non-smoker protection laws being enforced 2007-2008 on federal and state level. This is reflected by a halving of urinary cotinine concentrations. Nevertheless, our results indicate that passive smoke is still a relevant source of harmful pollutants for many children and adolescents in Germany, and thus support the need for further efforts to reduce passive smoke exposure, especially in the private environment.