Children who live with smokers miss more school days due to illnesses including ear infections and chest colds compared with those who live in smoke-free homes, a new study suggests.

CNN reports the new study looked at how many days of school children ages 6 to 11 missed, and the reasons they were absent. Children who lived with at least one smoker missed an average of one to two more days of school each year, compared with those who did not live with any smokers. Children living with two or more adult smokers had more ear infections per year than those who lived with one smoker or no smokers.

In the journal Pediatrics, the researchers conclude families could reduce their children’s school absenteeism by 24 to 34 percent if smokers in the home quit. The study notes about one-third of children in the United States live with a smoker.