Secondhand smoke exposure and hair nicotine in children: age-dependent differences

A significant proportion of children in the United States remain exposed to secondhand smoke (SHS). We are reporting on relationships observed between parental report of their child's SHS exposure in two groups of children (ages 2-5 years and 9-14 years) with a biological marker of long-term SHS exposure, hair nicotine.

Participants were healthy children recruited via convenience sampling for two age groups: 2-5 years and 9-14 years. The presence and amount of SHS exposure were assessed by both questionnaire and hair sampling for nicotine determination.

A total of 115 participants were recruited (54 toddlers and 61 youth). The groups were similar in terms of demographics and reported SHS exposure. Hair nicotine levels were significantly different by age group, with toddlers having higher levels than youth. The most important independent determinants of hair nicotine were toddler age group, receiving Medicaid for health insurance, and number of smokers the subject was exposed to in 24 hr.

Our findings suggest that young children who are insured by Medicaid have higher levels of hair nicotine, a biomarker of SHS exposure, when compared with an older age group. Further efforts to protect this vulnerable population and mitigate their lifetime risks of SHS exposure-related morbidities are warranted.