Lungs of adults who had grown up with secondhand smoke had more `` holes '' Many `` holes '' -- less dense areas of lung -- are characteristic of emphysema . Even though smoke-exposed lungs functioned fine , there 's concern for future health . Comment:
Lungs of adults who had grown up with secondhand smoke had more `` holes '' Many `` holes '' -- less dense areas of lung -- are characteristic of emphysema . Even though smoke-exposed lungs functioned fine , there 's concern for future health . About 24 million people in the United States have emphysema , chronic bronchitis .