Association between children’s secondhand co-exposure to tobacco and cannabis smoke and elevated urinary cotinine levels: a cross-sectional analysis

Abstract Background: Cannabis use is far more common among adults who smoke tobacco than adults who do not, and its use is increasing among people who smoke tobacco with children living in the home. Given the well-established evidence that caregiver smoking is the primary source of children’s secondhand exposures to these products, the increasing trend in caregiver co-use is raising public health concerns about children’s co-exposure. Emerging data indicates that adult co-use is linked to additive health consequences, such as