With legal commercialization of cannabis in a growing number of US states, increasing numbers of children have experienced unintentional cannabis exposure resulting in calls to poison control centers, health care visits,1 and hospitalizations.2,3 Edible cannabis products, which can have a high concentration of δ-9-tetrahyrocannabinol and may resemble foods that appeal to youth, have been implicated in many such exposures.4,5 In addition, edible products are often sold with multiple doses per package, meaning ingestion of large quantities is possible before effects are realized. Use of edible cannabis products has increased over time,6,7 but we lack national estimates of edible-involved pediatric cannabis exposures.
We obtained data on cannabis-involved human exposure calls for children aged 0 to 9 years reported to US poison centers from January 1, 2017, to December 31, 2019. Data were extracted from the National Poison Data System (NPDS) in March 2020. The NPDS records the type of product involved in an incident using standardized codes, with generic codes for products that have no reported manufacturer.8 Data were composed of all closed incidents involving a cannabis generic code, including the code for edible products (added to NPDS November 16, 2016). Cannabidiol-only and synthetic cannabinoid exposures were excluded.
We compared edible exposures to all other types of cannabis exposures (eg, dried plant, concentrated extracts) and examined differences by age, sex, intentionality, caller location, and medical outcomes as defined by NPDS.8 We evaluated changes in exposure counts per quarter using linear regression and testing for differences in trend between edible and nonedible exposures. For 2019, we compared cases in states with legal adult cannabis use to cases in states without, including states with medical cannabis. Comparisons were assessed by using χ2 tests. Stata 16 software (Stata Corp, College Station, TX) was used and α = .05. The Washington State University Institutional Review Board determined this study was exempt from review.
There were 4172 cannabis exposure cases among children aged 0 to 9 years during the study period, of which 45.7% (n = 1906) were associated with edible cannabis products (Table 1). From 2017 to 2019, cannabis product exposures increased overall (slope coefficient [β] for quarter 31.6 [95% confidence interval [CI]: 26.0–37.3]), as did the proportion of cannabis cases that were associated with edible products (Fig 1). The increase in edible-related exposures per quarter (β = 26.0; 95% CI: 23.6–28.3) was greater than the increase in nonedible cannabis exposures (β = 5.7; 95% CI: 1.4–9.9), confirmed by a significant interaction term in a combined model (interaction term coefficient 20.3; 95% CI: 15.8–24.8; P < .001).
Children aged 3 to 5 years experienced the highest proportion of all exposures (43.1%). Most cases were exposed by ingestion (72.0%). A small proportion experienced major (1.4%) or moderate (15.4%) medical outcomes. In 2019, areas with legal adult cannabis use reported greater pediatric cannabis exposures compared with states without this policy: 975 exposures (8.9 per 100 000 population) versus 972 exposures (3.4 per 100 000 population). The proportion of calls due to edible cannabis product exposures was greater in legal states than in states without this policy: 62% vs 46% (P < .001).
Poison center calls associated with pediatric exposure to cannabis increased in the United States from 2017 to 2019; the increase appears to be largely composed of unintentional exposures to edible cannabis products. Pediatric exposures were more frequent, and more often involved edible products, in states with legal adult cannabis use.
A limitation of these data is that they rely on self-reports, potentially leading to underestimation of cases. Data were extracted from the NPDS before the annual “locking” of the database,8 so the 2019 data may be subject to minor changes.
The trend we observed could be expected to continue or increase. Cannabis consumers may shift from combustible to edible products because of the epidemic of e-cigarette– and vaping product–associated lung injury in late 2019. In addition, as many states close or restrict access to school and child care centers to mitigate the coronavirus disease pandemic, increases in unintentional ingestions of potentially harmful substances at home are of growing concern. State governments, particularly those with legal adult use, should consider issuing additional warnings about safe storage of cannabis. Regulators should ensure that packaging policies require child-resistant plain and opaque containers and that products, particularly edible products, do not appeal to children.
We thank Nathaniel Pham of the American Association of Poison Control Centers for assistance with data retrieval.
Dr Whitehill conceptualized and designed the study, drafted the initial manuscript, and reviewed and revised the manuscript; Dr Dilley conducted the analyses and reviewed and revised the manuscript; Dr Brooks-Russell conceptualized and designed the study and critically reviewed and revised the manuscript; Ms Terpak contributed to data analysis and critically reviewed and revised the manuscript; Dr Graves conceptualized and designed the study, obtained funding, and critically reviewed and revised the manuscript; and all authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.
FUNDING: Supported in part by funds provided for medical and biological research by the State of Washington Initiative Measure No. 171. The funder/sponsor did not participate in the work.
POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.
FINANCIAL DISCLOSURE: The American Association of Poison Control Centers (AAPCC) (http://www.aapcc.org/) maintains the national database of information logged by the country’s poison centers (National Poison Data System). Case records in this database are from self-reported calls: they reflect only information provided when the public or health care professionals report an actual or potential exposure to a substance (eg, an ingestion, inhalation, or topical exposure, etc) or request information and/or educational materials. Exposures do not necessarily represent poisoning or overdose. The AAPCC is not able to completely verify the accuracy of every report made to member centers. Additional exposures may go unreported to poison centers, and data referenced from the AAPCC should not be construed to represent the complete incidence of national exposures to any substance(s).