Children exposed to secondhand smoke have higher levels of carbon monoxide in their blood than adults, according to researchers at Tufts Medical Center who said kids who breathe secondhand smoke can be exposed to carbon monoxide levels equal to those of adult smokers.

Medical News Today reported Oct. 20 that researchers studied levels of carboxyhemoglobin in 200 children ages one to 12. Carboxyhemoglobin, which is formed when carbon monoxide binds to blood cells, cannot deliver oxygen to essential body tissue like the brain, heart and muscles. Long-term, low-level exposure to carboxyhemoglobin could lead to changes in lung and heart tissue. The most common source of elevated carboxyhemoglobin among children is secondhand smoke.

Researchers found that the potential level of exposure was higher in young children. "The physiology of children -- especially the youngest -- is different from that of adults," noted study lead author Branden Yee. "Children breathe in a greater amount of air per body weight compared to adults."

Yee suggested that high carboxyhemoglobin levels could be explained by the fact that the youngest children are the most dependent on their parents, meaning they are exposed to the same things as their parents. He recommends combining physician intervention and technology to help educate parents about how smoking could affect their children.

"The simple, noninvasive device we used to test exposure may encourage healthcare providers to ask further questions of children and their parents regarding smoking habits," he said. "Personalized education coupled with the act of physically showing a parent the carboxyhemoglobin measurement in his or her child's blood may provide a graphic and concrete message to that parent."

Yee and his research group presented their findings at the American Society of Anesthesiologists' 2008 annual meeting.