U.S. health officials are warning doctors to be on the lookout for possible cases of lead poisoning in children after at least 22 toddlers in 14 states were sickened by lead linked to tainted pouches of cinnamon apple puree and applesauce.

Children ages 1 to 3 were affected, and at least one child showed a blood lead level eight times higher than the level that raises concern, the Centers for Disease Control and Prevention said.

There’s no safe level of lead exposure, but the CDC uses a marker of 3.5 micrograms per deciliter to identify children with higher levels than most. The affected children’s blood lead levels ranged from 4 to 29 micrograms per deciliter.

The reported symptoms included headache, nausea, vomiting, diarrhea, a change in activity level and anemia.

The illnesses are part of an outbreak tied to recalled pouches of fruit puree marketed to kids from the brands WanaBana apple cinnamon fruit puree and Schnucks and Weis cinnamon applesauce pouches. The products were sold in stores and online.

Parents and caregivers should not buy or serve the products, and kids who may have eaten them should be tested for lead levels. Children who are affected may show no symptoms, experts said.

Lead exposure can lead to serious learning and behavior problems. Heavy metals like lead can get into food products from soil, air, water or industrial processes, according to the American Academy of Pediatrics.

The CDC said there were cases in the following states as of Nov. 7: Alabama, Arkansas, Louisiana, Maryland, Missouri, New Mexico, New York, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Texas and Washington.