Many parents think they are protecting their children by smoking outside on the porch or patio. However, a new study finds that these practices aren’t enough to protect most children from harmful exposure to tobacco smoke.

In this unique Israeli study, researchers tested for nicotine in the hair of children whose parents smoke. Nicotine was found in their hair of six out of 10 children of parents who restrict smoking to the porch or outside the house.

This was the second stage of the study. Results of the first stage, published in September 2021, revealed that 70 percent of the children of smoking parents had measurable nicotine particles in their hair.

For the present study, the researchers examined the data by location of parental smoking and found that 62% of the children of parents who smoke outside the house had nicotine in their hair.

Their recommendation: “Smoking should be entirely avoided within a range of 10 meters [11 yards] from the house. Likewise, in open areas, smokers should maintain a distance of at least 10 meters from the children.” 

The study was led by Prof. Leah (Laura) Rosen from the School of Public Health in the Sackler Faculty of Medicine, Tel Aviv University.

“It is known that smoking outside the house, even when the doors and windows are fully closed, does not completely protect children from exposure to tobacco smoke,” Rosen said, noting that in many Israeli homes the porches are directly adjacent to the living areas and may even be partially open, allowing smoke to drift inside.

“Once in the home, the smoke is absorbed into the environment, for example, into the furniture or walls or rugs, and is then gradually discharged into the air over weeks or months. Further, this residual smoke, known as thirdhand smoke, can be absorbed into the body from the environment via swallowing or through the skin, especially among infants and small children,” she said.

“In addition, smoking parents transmit the toxins from the tobacco smoke on their skin, on their hands, in their hair, on their clothing. Therefore it is recommended to brush teeth, wash hands and change clothes after smoking, before contact with children.”

Also participating in the study were Prof. David Zucker from the Department of Statistics and Data Science, Hebrew University, Jerusalem; Shannon Gravely from the Department of Psychology, Waterloo University, Canada; Michal Bitan from the Computer Science Department, the College of Management; Anna Rule from the Department of Health and Environmental Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore; and Vicki Meyers from the Gertner Institute for Epidemiology and Public Policy Research, Sheba Medical Center.

The study was published in the International Journal of Environmental Research and Public Health.