Experts are cautiously welcoming the results of the latest government study on childhood asthma.
The study published online in the journal Pediatrics finds that after going up for decades, asthma rates in U.S. children have quieted down.
The 2001-13 study suggests that a possible plateau in childhood obesity rates and declines in air pollution are possible factors.
Overall, average asthma rates among kids aged 17 and younger increased slightly, then leveled off and declined by the study's end.
Declines in the most recent years were in children younger than 5, Mexican kids, those in the Midwest and those from families that weren't poor. Rates plateaued among whites and those living in the Northeast and West, but increased in those aged 10 to 17, kids from poor families and those living in the South.
Rates increased but then plateaued among blacks.