Cases of fentanyl poisoning in children across the U.S. has been steadily increasing for most of the past decade, according to a new study published Friday.

Researchers looked at over 3,000 incidents of nonfatal fentanyl exposure in children up to 19 years old that were reported to poison centers, and found a 1,194.2% increase between 2015 and 2023, according to the study published in the American Journal of Drug and Alcohol Abuse.

The exposures were categorized as either misuse or abuse, or as unintentional. During the studied period, the percentage of misuse or drug abuse cases increased from 26.1% to 39.2%, while there was a decrease in unintentional exposures, from 47.8% to 35.4%.

When the numbers were broken down into two age groups, teenagers 13 to 19 years of age were more likely to have been exposed to fentanyl than kids 12 and younger. There were 379 fentanyl exposures among children ages 12 and under reported to poison centers in 2023, compared to 514 among teens ages 13 to 19 that year, researchers found.