# Polycyclic aromatic hydrocarbons and cannabinoids in secondhand cannabis smoke. > **Author:** Benjamin Caplan, MD (ABFM Board Certified, MA Lic. #240562, NPI: 1962722637) > **Publisher:** CED Clinic (https://cedclinic.com) > **Canonical URL:** https://cedclinic.com/polycyclic-aromatic-hydrocarbons-and-cannabinoids-in-secondhand-cannabis-sm/ > **Published:** 2026-04-28T04:02:32-04:00 | **Last Modified / Clinically Audited:** 2026-09-28T17:16:25-04:00 > **Clinical Summary:** The legalization of cannabis is exposing more people to secondhand smoke (SHS) generated during cannabis use. Given the serious health effects caused by toba... --- CED Clinical Relevance  #62Notable Clinical Interest  Emerging findings or policy developments worth monitoring closely. 🔬 Evidence Watch  |  CED Clinic Journal Environment international Study Type [Clinical Study](https://cedclinic.com/cannabis-hyperemesis-syndrome-psychiatric-risk/) Population Human participants Why This Matters This item covers developments relevant to [cannabis medicine](https://cedclinic.com/essential-oils-industrial-hemp-antimicrobial-benefits/) and [clinical practice](https://cedclinic.com/cannabis-reproductive-health-women-clinical-evidence/). Clinicians monitoring evidence in this area should review the source material. Clinical Summary The legalization of cannabis is exposing more people to secondhand smoke (SHS) generated during [cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/). Given the serious health effects caused by tobacco SHS, there is a need to assess the potential health effects of exposure to cannabis SHS. As a step toward this, we measured the concentrations of cannabinoids, nicotine and polycyclic aromatic hydrocarbons (PAHs) in air samples collected in public places where cannabis was being consumed. These were compared with concentrations in exhaled aerosols from cannabis smoking and vaping, and in tobacco SHS. Tetrahydrocannabinol concentrations were 22 to 255 µg/m Dr. Caplan’s Take “This is a development worth tracking. The clinical implications will become clearer as more evidence accumulates.” Clinical Perspective 🧠 Clinicians should review this item in the context of their current practice and patient population. 💬 Join the Conversation Have a question about how this applies to your situation? [Ask Dr. Caplan →](https://benjamincaplan.com/ask-dr-caplan) Want to discuss this topic with other patients and caregivers? 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Share it: [X Share on X](https://twitter.com/intent/tweet?text=Just%20read%20this%20on%20CEDclinic.com%3A%20Polycyclic%20aromatic%20hydrocarbons%20and%20cannabinoids%20in%20secondhand%20cannabis%20smoke.%20%40drcaplan&url=https%3A%2F%2Fcedclinic.com%2Fpolycyclic-aromatic-hydrocarbons-and-cannabinoids-in-secondhand-cannabis-sm%2F)[in Share on LinkedIn](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fcedclinic.com%2Fpolycyclic-aromatic-hydrocarbons-and-cannabinoids-in-secondhand-cannabis-sm%2F)[🦅 Share on BlueSky](https://bsky.app/intent/compose?text=Just%20read%20this%3A%20Polycyclic%20aromatic%20hydrocarbons%20and%20cannabinoids%20in%20secondhand%20cannabis%20smoke.%20via%20%40drcaplan.bsky.social%20https%3A%2F%2Fcedclinic.com%2Fpolycyclic-aromatic-hydrocarbons-and-cannabinoids-in-secondhand-cannabis-sm%2F)[📷 Follow on Instagram](https://www.instagram.com/drbenjamincaplan)[📝 Read more on Substack](https://doctorapprovedcannabis.substack.com/)[🔔 Subscribe via RSS](https://cedclinic.com/feed/) 📰 Source: [https://pubmed.ncbi.nlm.nih.gov/41793955/](https://pubmed.ncbi.nlm.nih.gov/41793955/) ## FAQ ### Why are researchers studying secondhand cannabis smoke? Legalization is exposing more people to secondhand smoke produced during [cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/). Because tobacco secondhand smoke causes serious health effects, the researchers argue there is a need to assess the potential health effects of exposure to cannabis secondhand smoke. The study was published in Environment International. ### What did researchers measure in secondhand cannabis smoke, and how? They measured concentrations of cannabinoids, nicotine, and polycyclic aromatic hydrocarbons (PAHs) in air samples collected in public places where cannabis was being consumed. These levels were then compared with concentrations in exhaled aerosols from cannabis smoking and vaping, and with tobacco secondhand smoke. [https://cedclinic.com/contact/](https://cedclinic.com/contact/) Physician-Led, Whole-Person Care A doctor who takes the time to truly understand you. 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Health, Longevity, Wellness One-on-One Cannabis Guidance Metabolic Balance [Leave a Message](https://cedclinic.com/contact/) [Metabolic Care](https://cedclinic.com/metabolic/metabolic-how-it-works/) [Medical Consulting](https://cedclinic.com/book/) [Cannabis Care](https://cedclinic.com/book/) [https://cedclinic.com/contact/](https://cedclinic.com/contact/) ### Related --- ### Verification & Medical Governance - **Lead Clinical Author:** Benjamin Caplan, MD - **Credentials:** Board Certified in Family Medicine (ABFM), Former CMO Canna Care Docs (250,000+ patients supervised), Founder & CMO CED Clinic & CED Foundation, Author of *The Doctor-Approved Cannabis Handbook* (Penguin Random House). - **Clinical Scale:** 350,000+ lifetime evaluations overseen; 81,008-patient Real-World Evidence Registry (`~/.ced_rwe_vault.db`); 125,000+ peer-reviewed study literature observatory (`http://localhost:8768/api/explorer/terminal`). - **License Verification:** Commonwealth of Massachusetts License #240562 (https://checkahealthlicense.mass.gov/). - **NPI Registry:** 1962722637 (https://npiregistry.cms.hhs.gov/provider-view/1962722637). - **Ethics & Data Privacy:** Clinical registry observations adhere strictly to HIPAA Safe Harbor de-identification (45 CFR § 164.514(b)) and criteria for secondary research exemption under 45 CFR § 46.104(d)(4).