Children of Smokers Carry Tobacco Toxins on Their Hands
By Salynn Boyles
Children of smokers routinely carried nicotine on their hands, indicating that exposure to thirdhand smoke appears to play an important role in overall tobacco exposures among young children whose parents smoke cigarettes, according to researchers.
In the pilot study, children of smokers with exposures to secondhand smoke had higher than expected levels of nicotine on their hands, implying exposure to thirdhand smoke as well, reported E. Melinda Mahabee-Gittens, MD, of Cincinnati Children’s Hospital Medical Center, and colleagues.
The finding of a significant association between hand nicotine and salivary cotinine, which is a biomarker of systemic tobacco exposure, suggests that thirdhand smoke exposure may contribute to overall tobacco exposure in children, independent of exposure to secondhand smoke, they wrote in Tobacco Control.
“The nicotine levels on the hands of children in our study were exceptionally high,” Mahabee-Gittens told MedPage Today, adding that these levels tended to be significantly higher than those previously reported in non-smoking adults.
Breathing secondhand smoke exhaled by smokers has been shown in numerous studies to pose significant health risks to young children, but the impact of exposure to smoke residues left on dust and surfaces — known as thirdhand smoke — on children’s health is not known. However, dust and surfaces have been shown to be important sources of lead and pesticide exposure in young children.
The study enrolled 25 children (mean age 5.4 years) who presented to a single emergency department (ED) from April to September of 2016 with a potentially secondhand smoke-related illness. All the children had a parent who smoked and were considered at risk for smoke exposures.
The children provided saliva samples, which were analyzed for cotinine. The palm and fingers of their dominant hands were wiped by trained research staffers and analyzed for nicotine.
The children’s parents reported sociodemographic information and smoking patterns, and the children’s medical records were reviewed for chief complaint at ED presentation, medical history, and discharge diagnosis.
Statistical analysis included calculated geometric means (GeoMs), confidence interval, medians and interquartile range (IQR). The researchers conducted linear regression analysis to examine associations between salivary cotinine and hand nicotine, sociodemographics, smoking behaviors, household characteristics, and clinical findings.
All the children in the study had detectable hand nicotine, at levels ranging from 18.3 to 690.9 ng/wipe, and all but one had detectable cotinine (range 1.2-28.8 ng/mL).
Mahabee-Gittens said the GeoM nicotine exposure among the children was 86 ng/wipe, which was more than three times the mean level reported in a previous study involving non-smoking adults living with active smokers.
One child had a nicotine level of close to 691 ng/wipe, which was higher than the level expected in an active smoker.