One in Five Toddlers Tested Positive for Marijuana Metabolites

In a small sample of young children in New York City, 20.8% had detectable marijuana metabolites in their urine, with higher rates among those exposed to household tobacco smoke.

Sangmo, Lodoe et al.·Pediatric research·2021·Preliminary EvidenceCross-Sectional
RTHC-03495Cross SectionalPreliminary Evidence2021RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Cross-Sectional
Evidence
Preliminary Evidence
Sample
N=53

What This Study Found

Among 53 children aged 0-3 years, 20.8% had detectable urinary COOH-THC (a marijuana metabolite), and children with high tobacco smoke exposure were significantly more likely to test positive (p<0.01).

Key Numbers

53 children; 20.8% had detectable COOH-THC; 90.2% had detectable cotinine; 34.8% of children in housing allowing smoking had detectable COOH-THC vs 13.0% in smoke-free housing; high tobacco exposure significantly associated with COOH-THC detection (p<0.01).

How They Did This

Cross-sectional study collecting urine samples from children at well-child visits or inpatient stays at Mount Sinai (2017-2018), analyzed for cotinine and COOH-THC with parent surveys.

Why This Research Matters

Objective biomarker evidence that young children are absorbing marijuana smoke, even in a state where recreational use was then illegal, underscores that secondhand exposure in shared living spaces is a measurable public health concern.

The Bigger Picture

As more jurisdictions legalize recreational cannabis, these biomarker data provide objective evidence that secondhand marijuana smoke reaches children, which could inform smoke-free housing and public health policies.

What This Study Doesn't Tell Us

Very small sample size (53 children); convenience sample from a single hospital; cross-sectional design; cannot determine health effects of detected levels.

Questions This Raises

  • ?At what urinary concentration of COOH-THC might health effects become concerning for young children?
  • ?Would smoke-free housing policies reduce detectable metabolite levels?

Trust & Context

Key Stat:
20.8% of children aged 0-3 had detectable marijuana metabolites in their urine
Evidence Grade:
Small convenience sample provides preliminary biomarker evidence requiring replication in larger studies.
Study Age:
Urine samples collected 2017-2018, when recreational marijuana was illegal in New York.
Original Title:
Secondhand marijuana exposure in a convenience sample of young children in New York City.
Published In:
Pediatric research, 89(4), 905-910 (2021)
Database ID:
RTHC-03495

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

A snapshot of a population at one point in time.

What do these levels mean? →

Frequently Asked Questions

How were children exposed to marijuana smoke?

Through secondhand smoke in their living environments. Children in attached housing where smoking was allowed had nearly triple the detection rate (34.8%) compared to smoke-free housing (13.0%).

Does detecting marijuana metabolites mean the children are harmed?

This study confirmed exposure through biomarkers but did not assess health effects. The long-term impact of secondhand marijuana smoke exposure on children's health remains an open research question.

Read More on RethinkTHC

Cite This Study

RTHC-03495·https://rethinkthc.com/research/RTHC-03495

APA

Sangmo, Lodoe; Braune, Tanya; Liu, Bian; Wang, Lanqing; Zhang, Li; Sosnoff, Connie S; Blount, Benjamin C; Wilson, Karen M. (2021). Secondhand marijuana exposure in a convenience sample of young children in New York City.. Pediatric research, 89(4), 905-910. https://doi.org/10.1038/s41390-020-0958-7

MLA

Sangmo, Lodoe, et al. "Secondhand marijuana exposure in a convenience sample of young children in New York City.." Pediatric research, 2021. https://doi.org/10.1038/s41390-020-0958-7

RethinkTHC

RethinkTHC Research Database. "Secondhand marijuana exposure in a convenience sample of you..." RTHC-03495. Retrieved from https://rethinkthc.com/research/sangmo-2021-secondhand-marijuana-exposure-in

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.