Thirdhand smoke may cause respiratory problems in kids

Exposure to residual tobacco and nicotine lingering in carpets and upholstery in rooms, as well as a smoker's fingers, can cause respiratory problem in children, a study has found.

The harmful effects of exposure to tobacco smoke have been known for many years. Cigarette and cigar smokers are at significantly higher risk of contracting all sorts of respiratory maladies, and research linking secondhand smoke to cancer goes back nearly three decades.

Researchers at Cincinnati Children's Hospital Medical Center and the University of Cincinnati in the US have found more evidence of the potentially harmful effects of exposure to the residue and particles left behind by tobacco smoke.

According to a study published in the journal Tobacco Use Insights, not smoking around children does not prevent exposure to nicotine.

They also found that that higher levels of exposure to tobacco smoke residue -- which likely includes carcinogenic tobacco-specific nitrosamines -- may be linked to respiratory problems.

"It just goes to show that indoor smoking bans don't necessarily protect children from tobacco smoke exposure and related pollutants, such as thirdhand smoke," said Ashley Merianos, from University of Cincinnati in the US.

"It also shows that exposure to tobacco smoke toxicants is more widespread than previously thought because exposure in children is not limited to inhaling secondhand smoke," said Melinda Mahabee-Gittens, an attending physician at Cincinnati Children's.

Research staff collected wipes of the dominant hands of 104 children between April 2016 and August 2017 with complaints potentially linked to tobacco smoke exposure and who had at least one caregiver who smoked.

The handwipes were then analysed for nicotine.

The research explored several variables, including the self-reported smoking behaviours of the children's caregivers, as well as the number of smokers living with the child.

The research also looked at the medical records of the children for possible smoke exposure-related complaints such as wheezing and cough, as well as past medical histories and discharge diagnoses.

The study found significant levels of nicotine on the hands of children of smokers whose caregivers did not smoke in their presence, averaging 82 nanograms (ng) of nicotine.

A similar amount was found on the hands of children whose caregivers smoked between one and five cigarettes per day in their presence.

Children whose parents smoked 15 or more cigarettes around them had nicotine levels on their hands in excess of 200 ng.