Fig. 1: Questionnaire-determined density plots of cotinine and trans-3’-hydroxycotinine concentrations. | Journal of Exposure Science & Environmental Epidemiology

Fig. 1: Questionnaire-determined density plots of cotinine and trans-3’-hydroxycotinine concentrations.

From: Assessing secondhand and thirdhand tobacco smoke exposure in Canadian infants using questionnaires, biomarkers, and machine learning

Fig. 1

The distribution of the log-transformed urinary cotinine (left) and 3HC (right) concentrations by two questions: “How many cigarettes (on average) are smoked at the home daily in the child’s early life”, and “How many smokers lived at the home during pregnancy?”. Vertical lines reflect cut-points of assumed exposure to very little to no SHS or THS (left), moderate SHS (middle), and regular SHS exposure (right). The dashed lines reflect 0.25 and 30 ng/mL, while dotted lines indicate 0.50 and 60 ng/mL. Density curves were not created for categories with two or fewer participants.

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