A study published this week in the journal Circulation revealed an increased risk of heart disease in children in adulthood if they were exposed to secondhand smoke.

The study stated that parents who try to reduce smoking in front of their children, their children are exposed to the risk of developing heart disease in adulthood at twice the rate compared to children whose parents do not smoke at all, while children whose parents smoke in front of them naturally, the risk of heart disease increases by an average Four times more compared to other children.

“This study proves that exposure to secondhand smoke during childhood increases the risk of developing heart disease in the future,” said Stanton Glantz, a professor at the University of California, San Francisco.

According to the CDC, about 60 percent of children ages 3 to 11 are exposed to secondhand smoke, most likely indoors.