The high level of toxicity in the smoke that comes from the end of a burning cigarette — side stream smoke — is a major component in passive smoking that damages the children’s blood vessels, the study said.
“Children exposed to cigarette smoke may develop early heart disease as adults due to poorly functioning and stiffer blood vessels,” said paediatric cardiologist Geetha Raghuveer, from Children’s Mercy Hospital in Missouri, US.
“Some babies who were exposed to cigarette smoke while in the womb might die suddenly during infancy,” Raghuveer said in a statement from the American Heart Association.
Compared to adults, children are more vulnerable to passive smoking exposure because they cannot control tobacco use in their surroundings, and are particularly susceptible physically to the smoke’s effects.
Cigarette smoke contains a host of chemicals that can impact health by causing changes in blood flow, blood vessels, blood pressure and heart rhythm.
Besides damaging heart and arteries, passive smoking has also been associated with other cardiovascular risk factors — obesity, high cholesterol, and insulin resistance — that are linked to diabetes.
Moreover, there are significant chances of children becoming smokers themselves if their parent’s smoke.
Blood tests in a 2011-12 national study, detected a nicotine metabolite called cotinine, in nearly 41 per cent of children aged between three and 11 years, and 34 per cent among kids aged between 12 to 19.
This result was despite declines in recent decades among both adult smokers and the proportion of young children and adolescents living with smokers.
There is also a clear disparity in exposure among poor families compared with their peers, the researchers said.
“Parents should consider making their children’s environment smoke-free as cigarette smoke exposure is harmful for children’s long-term heart health and could even shorten life expectancy,” Raghuveer said.
“Encouraging adults to quit smoking is a cost-effective and health-enhancing strategy that could benefit both,” Raghuveer noted, adding “raising cigarette taxes to discourage smoking could also work.”
The statement is published in the journal Circulation.