Experts are cautiously optimistic about a new government study that suggests that asthma rates among children are declining.

FOX's Jeff Monosso reports from Chicago:

The 2001 to 2013 government survey published online in the Journal Pediatrics finds that after going up for decades, asthma rates in U.S. children have quieted down.

Declines in the most recent years were in children younger than 5, including kids in the Midwest and those from non poor families.

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 also increased, but then leveled off among black children.

The study suggests say possible plateau in childhood obesity rates and declines in air pollution as possible factors.

In Chicago, Jeff Monosso, FOX News.