UCSF

INTRODUCTION: In 2016, California legalized cannabis for adult recreational use; after recreational sales began in 2018, it became the largest retail market worldwide. This study profiled specific risks and prevention opportunities across age groups and examined changes in medically significant child cannabis exposures before and after legalization. METHODS: Researchers conducted analyses, including interrupted time series, to examine 1,695 California Poison Control System reports of cannabis exposure in children aged 0-17 years from 2010 to 2020. Analyses were confined to moderate and severe exposures, identified by California Poison Control System toxicologists as requiring medical attention. RESULTS: Monthly rates of moderate/severe cannabis exposure per million children increased after legalization (β=0.06; 95% CI=0.05, 0.08), especially in children aged <5 years. Fourteen percent required critical care admission. Exposures were primarily unintentional in younger children (87.7%-99.2%) and intentional in adolescents (85.5%). Across all ages, most exposures occurred in the home (94.0%) and involved edible products (83.5%). An analysis of packaging on edible brands frequently cited in health records found that most could be easily mistaken for popular candies and snack foods. CONCLUSIONS: After cannabis legalization in California, reports of child cannabis exposures requiring medical attention increased significantly. Most reported cannabis exposures occurred in the home through the ingestion of edible products, often packaged to look like popular candy and snack food brands. To prevent these harms, cannabis legalization should be accompanied by robust marketing and packaging regulations (e.g., plain labels, larger warning labels). Secondary prevention should focus on educating parents and caregivers on safe cannabis storage in the home.