May 16, 2017
2 min read

Children at increased risk for third-hand smoke exposure through contaminated surfaces

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Children who live in households with smokers exhibited significant levels of tobacco smoke toxins on their hands through contact with contaminated surfaces – referred to as “third-hand smoke exposure” –  despite not being present during smoking activity, according to research published in Tobacco Control.

“Research shows the persistent residue from second-hand smoke accumulates in dust, in objects, on home surfaces and on smokers’ skin and clothes,” Melinda Mahabee-Gittens, MD, physician in the division of emergency medicine at Cincinnati Children’s Hospital Medical Center, and colleagues wrote. “Commonly referred to as thirdhand smoke, non-smokers may be exposed to toxicants — for example, tobacco-specific nitrosamine — via inhalation, ingestion and dermal uptake transferred from indoor deposits and parents.”

Melinda Mahabee-Gittens, MD
Melinda Mahabee-Gittens

To understand whether third-hand smoke pollutants collect on children’s hands when they live in environments where tobacco use is common, researchers conducted a pilot study that included parents who were current smokers and children reporting to emergency departments with second-hand smoke (SHS)–-related illness. A baseline was created by measuring nicotine levels on the hands of children whose families were participating in an ongoing randomized control trial of an SHS reduction and smoking cessation intervention.

While also examining if hand nicotine levels are related to SHS, the researchers collected hand nicotine samples and measured salivary cotinine, along with information on smoking habits and sociodemographic data provided by participating parents. Additionally, the medical records of participating children were condensed by recording their chief complaint, medical history and discharge diagnosis.

Nicotine was detected on the hands of every child involved in the study (n = 25; age mean = 5.4 years), with levels ranging from 18.3 to 690.9 ng/wipe. Similarly, cotinine was detectable in all but one child, with levels between 1.2 to 28.8 ng/mL. Data demonstrated that children with higher levels of nicotine on their hands also had higher levels of cotinine. Younger children were the most likely to have higher levels of cotinine, regardless of nicotine levels on their hands.

Concerning the diagnosis of children exposed to third-hand smoke, 52% were discharged with an asthma or bronchiolitis diagnosis. No statistically significant associations between sociodemographic status, smoking habits and household or clinical characteristics were observed, and the smoking behaviors of parents were unrelated to their levels of nicotine and cotinine in their child.

“This is the first study to show that children’s hands hold high levels of nicotine even when parents are not smoking around them,” Mahabee-Gittens said in a press release. “Parents may think that not smoking around their child is enough, but this is not the case. These findings emphasize that the only safe way to protect children from smoke exposure is to quit smoking and ban smoking in the home.” — by Katherine Bortz

Disclosure: The researchers provide no relevant financial disclosures or conflicts of interest.