In some cases, magnet ingestions can be fatal, experts warn.
Researchers cautioned that in addition to toy standards, labeling requirements, safety advisories and product recalls, efforts to educate parents and children on the dangers of magnetic toys and novelty items such as fake piercings should continue.
In conducting the study, researchers examined magnetic ingestion trends at The Hospital for Sick Children in Toronto, Canada's largest children's hospital. The investigators analyzed over 2,700 emergency room visits for foreign body ingestion that occurred from April 2002 through December 2012.
The findings are scheduled for publication in The Journal of Pediatrics.
To be included in the study, the children had to be under 18 years old and have a confirmed or suspected magnet ingestion. "We chose to limit our scope to the alimentary tract because the majority of serious harm from magnets arises from perforations and fistulae of the stomach, small bowel and colon," study leader Dr. Matt Strickland said in a journal news release.
The researchers identified 94 children who met the study's criteria. Of these children, 30 had confirmed ingestion of more than one magnet.
When dividing the study years into two periods -- 2002 to 2009, and 2010 to 2012 -- the investigators found that overall magnet ingestions tripled after the introduction of small, spherical magnetic sets in 2009. Moreover, the number of injuries involving multiple magnets was nearly 10 times greater after 2009.
Of the magnet ingestion cases examined, six children needed surgery for sepsis or potential for imminent bowel perforation. All six of these injuries took place between 2010 and 2012, the findings showed.
The study also revealed that the average size of ingested magnets was about 70 percent smaller after 2009 than it was in the earlier time period.
"The increased number of high-risk injuries featuring multiple, smaller magnets" -- such as those used as so-called stress relief desk toys or as fake tongue or nose piercings -- is "concerning," noted Strickland.
The American Academy of Pediatrics has more about kids and magnet safety.