Nearly Half of Hospitalized Children of Smoking Parents Had Marijuana Metabolites in Their Urine | Research

The takeaway

Among children hospitalized in Colorado whose parents smoked tobacco, 46% had detectable marijuana metabolites in their urine, with exposure linked to parents who used marijuana daily, smoked it at home, and smoked in another room rather than outside.

Parents who use marijuana, pediatricians, public health policy makers.

46% of children tested had detectable marijuana metabolites; smoking in another room did not prevent exposure.

What the researchers found

46% of children had detectable COOH-THC (marijuana metabolite) and 11% had detectable THC itself. Of those with detectable THC, 6 of 9 were under 8 years old. Children with positive results were more likely to have parents who used daily, smoked (vs other forms), used in the home, and smoked in another room rather than outside.

Why it matters

This is among the first studies to biologically confirm secondhand marijuana smoke exposure in children. The finding that nearly half of tested children had detectable marijuana metabolites raises serious questions about passive exposure risks to developing children.

The numbers in context

Median child age: 6 years. 46% had detectable COOH-THC. 11% had detectable THC. Of 9 with detectable THC, 6 were under 8. No differences by age, sex, race, or socioeconomic status.

How the study worked

Cross-sectional study of children hospitalized in Colorado with parents in a smoking cessation study. Remaining urine samples were analyzed for cotinine and marijuana metabolites using LC-MS/MS.

What this study cannot tell us

Children were selected from a tobacco smoking cessation study, so all parents were smokers - not representative of all parents. Colorado-specific sample. Cannot determine health effects from exposure. Cannot distinguish secondhand smoke from other exposure routes.

How to read the evidence

Moderate - objective biological measurement with LC-MS/MS, but convenience sample from a tobacco cessation study.

When this study was published

Published in 2018. Colorado legalized recreational marijuana in 2012.

The bigger picture

As marijuana legalization expands, secondhand exposure to children is an emerging public health concern. Unlike tobacco, there are currently few public health campaigns or regulations specifically addressing secondhand marijuana smoke exposure.

Questions still open

What health effects does secondhand marijuana smoke have on children? Are current levels of exposure producing pharmacological effects? Should smoking-free policies explicitly include marijuana alongside tobacco?

Common questions

Can secondhand marijuana smoke affect children?

This study found that 46% of hospitalized children whose parents smoked tobacco also had marijuana metabolites in their urine. Parents who smoked marijuana in another room (rather than outside) did not adequately protect their children from exposure.

Does smoking marijuana in another room protect children?

Not effectively. This study found that children of parents who smoked marijuana in another room still had detectable marijuana metabolites. Parents who used marijuana daily and smoked at home (rather than outside) had children with the highest exposure.

Read the original research

Marijuana and Tobacco Coexposure in Hospitalized Children.

Pediatrics, 142(6)

View on PubMed ↗Publisher’s paper ↗

Citation

Wilson, Karen M; Torok, Michelle R; Wei, Binnian; Wang, Lanqing; Lowary, Michelle; Blount, Benjamin C. (2018). Marijuana and Tobacco Coexposure in Hospitalized Children.. Pediatrics, 142(6). https://doi.org/10.1542/peds.2018-0820