Researchers made this conclusion after more than half of the children who were part of a study tested positive for second-hand smoke exposure, although only a handful of their parents admitted to lighting up in their presence.

Parents may think their children are only exposed if they’re around someone actively smoking a cigarette, researchers said, or are unaware of where else their children might be breathing in smoke.

Second-hand smoke exposure in kids has been tied to – among other things – sudden infant death syndrome, respiratory problems, ear infections and asthma.

The study

In the study, published in the Archives of Pediatrics & Adolescent Medicine, researchers at the University of California in the United States, tested 496 blood samples from children to determine how many of them were exposed to second-hand smoke. The blood was tested for cotinine, a chemical produced by the body after it is exposed to nicotine.

Overall, 55% of the blood samples had a measurable amount of cotinine, which meant those children were exposed to smoke within three to four days prior to the blood being drawn. However, only 13% of parents admitted their child had been exposed to second-hand smoke.

“I think parents do not understand the various sources of potential exposure,” said Dr Neal Benowitz, one of the study’s co-authors. For example, kids can still get the effects of second-hand smoke if they spend time in a room where someone recently smoked.

In a Reuters Health report, the researchers advise parents to be cognisant of   their children’€™s exposure to second-hand smoke and if they are smokers, to stop smoking as soon as possible.

Although the study was conducted in the US, children in South Africa are at similar risk of second-hand smoke exposure, where between five and seven million people are estimated to smoke.

Source: Reuters Health