In recent years, the legalization of both medical and recreational marijuana has become the new normal across much of North America.

The problem: New research finds that as legalization has spread, so have cases of cannabis poisoning.

“We did a systematic review of published studies reporting on what happened to the rates of poisoning after legalization or decriminalization,” said study author Nicholas Buckley, a professor of clinical pharmacology, biomedical informatics and digital health at the University of Sydney in Australia.

“With either, the rate generally went up,” Buckley noted. “The extent to which it did was quite variable. But on average [poisoning risk] went up three to four times. The rises in children were even more dramatic.”