Child Cannabis Poisonings Increased Significantly After California Legalization | Research

The takeaway

Monthly rates of medically significant child cannabis exposures in California increased after legalization, with 83.5% involving edibles and 14% requiring critical care, predominantly affecting children under 5.

Pediatricians, policymakers designing cannabis regulations, parents, and public health advocates.

What the researchers found

Monthly rates of moderate/severe cannabis exposure per million children increased significantly after legalization (beta=0.06; 95% CI: 0.05, 0.08). 83.5% of exposures involved edible products. 94% occurred at home. Among children under 5, exposures were almost entirely unintentional (87.7-99.2%), while adolescent exposures were predominantly intentional (85.5%).

Why it matters

California has the world's largest legal cannabis retail market. The significant increase in child poisonings, overwhelmingly from edible products that resemble candy, provides direct evidence that current packaging and marketing regulations are insufficient to protect children.

The numbers in context

1,695 poison control reports (2010-2020). Monthly rate increase after legalization: beta=0.06 (95% CI: 0.05, 0.08). 83.5% involved edibles. 94% occurred at home. 14% required critical care. Children <5: 87.7-99.2% unintentional. Adolescents: 85.5% intentional.

How the study worked

Interrupted time series analysis of 1,695 California Poison Control System reports of cannabis exposure in children aged 0-17 from 2010 to 2020. Analysis focused on moderate and severe exposures requiring medical attention. Edible product packaging was also analyzed.

What this study cannot tell us

Poison control data captures only reported cases and likely underestimates true exposure rates. The study period (2010-2020) overlaps with both medical and recreational legalization phases. Cannot isolate the effect of recreational legalization from increasing product availability and awareness. Ecological design cannot establish individual-level causation.

How to read the evidence

Large dataset with robust interrupted time series design and clear temporal association, though poison control data has known underreporting limitations.

When this study was published

Published 2025, using 2010-2020 California Poison Control data.

The bigger picture

Every state and country legalizing cannabis faces this challenge. California's experience, as the largest market, sets a benchmark. The finding that most exposures involve edibles packaged to look like candy points to a specific, fixable problem: packaging regulations need to be stricter and better enforced.

Questions still open

Whether plain packaging regulations (like those used for tobacco in some countries) would reduce child exposures
How California's child exposure rates compare to states with stricter edible packaging laws

Common questions

Why are edibles the biggest risk for children?

Many cannabis edibles are gummies, chocolates, and cookies that look identical to regular candy and snacks. Young children cannot distinguish them from regular treats. The study found that packaging on frequently cited edible brands could easily be mistaken for popular candy products.

How serious are these exposures?

14% of the children in this study required critical care admission. Cannabis exposure in young children can cause sedation, breathing difficulties, and altered consciousness. While deaths are extremely rare, the experience is distressing and medically significant.

Read the original research

Characteristics and Trends in Child Cannabis Exposures During Legalization in California.

American journal of preventive medicine, 69(4), 107963

View on PubMed ↗Publisher’s paper ↗

Citation

Schmidt, Laura A; Jacobs, Laurie M; Matthay, Ellicott C; Roake, James; Lewis, Justin; Ho, Raymond; Apollonio, Dorie E. (2025). Characteristics and Trends in Child Cannabis Exposures During Legalization in California.. American journal of preventive medicine, 69(4), 107963. https://doi.org/10.1016/j.amepre.2025.107963