TUESDAY, March 11, 2003 (HealthDayNews) -- Even if parents who smoke step out of the house to have a puff, they are still putting their children's health at risk, particularly if those children already suffer from asthma.
That's the finding of the first study ever to measure the dose-related effects of parents' cigarette smoke on their children.
"We've known for a long time that secondhand smoke is harmful to children with asthma, but what we didn't know was whether that harm was dose-related. We now know that it is," says study author Dr. Nathan Rabinovitch, an allergist at the National Jewish Medical Center in Denver.
Rabinovitch presented his findings at the annual meeting of the American Academy of Allergy, Asthma and Immunology now underway in Denver.
What made the study possible is a newly developed portable monitor capable of registering air pollutants in levels less than 2.5 microns in size. That's a microscopic 1/12,700 of an inch. The monitor was also small enough for the 40 children in the study, all of whom had moderate to severe asthma, to wear daily for four months.
Over the course of the study, the children took a twice-daily lung function test. After comparing lung function tests of all the children, the result was clear: "Children who lived in a smoking household registered significantly higher levels of 'particulate matter' in their lungs -- a measure of pollution-related damage -- than children of non-smoking parents," Rabinovitch says.
Further, he says, children whose parents step out of the house to smoke were exposed to 30 percent less damaging lung particles than those whose families smoked indoors.
But, he adds, their rate of exposure was still significantly higher than that of nonsmokers -- up to 70 percent more.
While there clearly is a dose-dependant effect to secondhand smoke, experts say parents should not take this to mean that a little smoke exposure is OK.
"Just because the damage was less if parents smoked outdoors doesn't mean there wasn't damage. And parents of children with asthma who continue to smoke in any capacity, even outside the home, have to realize they are purposefully putting their children in harm's way," says Dr. Zab Mohsenifar, executive vice chairman of pulmonary and critical care medicine at Cedars Sinai Medical Center in Los Angeles.
The truth is, Mohsenifar adds, exposure to even one cigarette is one exposure too many for a child with asthma.
According to Mohsenifar, the take-home message is clear: "Even if you limit your smoking to outdoors, you are still exposing your child to significant damage. If you love your child, you must stop smoking; there is no other answer," Mohsenifar says.
More information
To learn more about asthma and secondhand smoke, visit The U.S. Environmental Protection Agency. To learn more about allergies visit the American Academy of Allergy, Asthma and Immunology.
