Here's another reason for smokers to quit: Their children have more potentially harmful bacteria in their nose and throat than children of nonsmokers.
"It is possible that the exposure to direct and secondhand smoking contributes to better attachment of harmful bacteria to the (lining of the nose and throat) in parents and their children," says Dr. Itzhak Brook, professor of pediatrics at Georgetown University in Washington, D.C.
He took mucus samples from 40 healthy children and 40 others who were prone to ear infections, as well as their parents, half of whom in each group smoked.
Significantly more potentially harmful bacteria were isolated from smoking parents and their children than from the nonsmokers and their children.
Nonsmoking parents of children prone to ear infections had less bacteria than the smokers, but their children had a comparable number of bugs found.
"It is possible that there may be sharing of harmful bacteria between the smoking parents and their children, as spread of organisms in the family setting can occur," Brook says.
Subscribe to our newsletters for our very best stories, recipes, style and shopping tips, horoscopes and special offers.