It had been on the rise for decades, but asthma rates among children appear to be calming down here in New Jersey and across the country.

David McNew, Getty Images

Researchers found the prevalence of asthma in children ages 17 and younger, which skyrocketed in the 80s and 90s, peaked at 9.7 percent in 2011 and remained steady until 2013 when it dropped to 8.3 percent.

The researchers published their 2001-13 study Monday in the journal Pediatrics.

Meanwhile, figures provided by the New Jersey Department of Health show 8.7 percent of New Jersey children had asthma in 2013, the latest year with available data. That's the same number as 2011, and a notch lower than 2012.

Asthma and allergy expert Dr. Leonard Bielory, a professor with the Environmental Prediction Center at Rutgers, said this leveling off of asthma cases could be thanks to stronger efforts in fighting obesity. It's not totally clear, he said, whether the positive change can be linked to cleaner air.

"We've gotten toward a cleaner environment, but I can't jump on that immediately," he said, noting certain environmental issues are still not in check and can lead to a greater likelihood of childhood allergies in the future.

Researchers are not sure whether the latest numbers are just a plateau or the start of a decreasing trend.

Sign up for the Newsletter

Get the best of delivered to your inbox every day.