10/11/22: Fine Particulate Matter Exposure from Secondhand Cannabis Bong Smoking

Fine Particulate Matter Exposure from Secondhand Cannabis Bong Smoking

About the webinar:

Secondhand cannabis smoke (SHCS) is a novel exposure source uncharacterized in homes, containing known health risk factors including exposure to several hundred toxic chemicals, carcinogens, and fine particulate matter (PM2.5), many at higher concentrations than tobacco smoke. Decades of secondhand tobacco smoke (SHTS) research demonstrate causal links to cancer, respiratory and cardiovascular diseases, preterm birth, and decreased immune function. These concerns have not translated to cannabis bong smoking, a popular consumption method in social settings among young adults, wherein smoke is drawn through water. Understanding SHCS exposures is critical to identifying proper industrial hygiene controls and public health policies to prevent toxic exposures in homes, apartments, and cannabis smoking lounges. Our study measured PM2.5 from SHCS and found that social cannabis bong smoking generated fine particulate matter levels 10 times greater than the highest daily concentration in the days the Bay Area experienced orange skies from wildfires. Even 12 hours after cannabis smoking ceased, fine particulate matter decayed slowly so that the daily average concentration still exceeded US EPA daily standard by 6-fold. This presentation is the first study to quantify SHCS fine particulate matter levels from social cannabis smoking in the home and discusses the dangers of social bong smoking in the home.

Learning Objectives

At the completion of this activity, the learner will be able to:

  • Discuss cannabis smoking trends including social cannabis bong smoking in homes

  • Compare PM2.5 exposure from social cannabis bong smoking to air quality standards and previous studies on tobacco smoking in homes

  • Summarize home secondhand cannabis smoke and secondhand tobacco smoke to understand the potential health risks of social cannabis bong smoking

Speaker: Patton Khuu Nguyen, MPH, ASP

Patton is a graduate of the 4+1 B.A. '18 and M.P.H. '19 program in Industrial Hygiene and Environmental Health Sciences at UC Berkeley. As an undergraduate, he helped identify an analytical method to detect quinones in ambient air as part of the Children's Health and Air Pollution Study. In 2017, he became UC Berkeley's inaugural Smoke and Tobacco Free Fellow as provided by the UC Office of the President. He worked closely with the University Health Services on a campus smoke-free campaign, while also completing an honors thesis on novel research on secondhand cannabis smoke in the BEAR Lab. After graduating with honors in 2018, he continued his ambient air pollution research and completed a capstone comparing exposures to polycyclic aromatic hydrocarbons and quinones in cities in California and China. His graduate work earned him the EHS Research Excellence award, only awarded to one student in the department who demonstrates high quality and outstanding research. Inspired by his Industrial Hygiene work, he was awarded the Center for Global Public Health research fellowship and completed a Summer 2019 practicum in Hanoi, Vietnam, working with an NGO and government agency to conduct qualitative research to support workers' rights and help improve working conditions. Patton now works at IBM as an Industrial Hygienist and Safety Professional leading business continuity and employee health planning. Overall, his past research and interests include secondhand cannabis smoke, ambient air pollution, toxicology, and workplace health and safety.


The Center for Occupational and Environmental Health designates this activity for a maximum of 1.0 Contact Hour. Participants should claim only the credit commensurate with the extent of their participation.

Certificates of Completion

Certificates of Completion will be available to webinar participants who are present for the complete, live webinar, and logged in with their registered email address. Call-in attendees are not eligible for certificates at this time - Please download the Zoom app to log in via email on your smartphone whenever possible.

In order to receive your Certificate of Completion, qualified learners must complete the post-webinar evaluation within 7 days of the webinar. A link to the evaluation will be emailed to qualified learners 24 hours after the webinar via no-reply@zoom.us. Qualified learners who submit their evaluation will receive a Certificate of Completion via email, and can also print/save the certificate from their browser after submitting their evaluation.

If you're not able to attend the live presentation, no problem! We record most presentations and will host them on our website provided we have permission to do so. Presentation recordings are not eligible for Certificates of Completion.


About Northern California Center for Occupational and Environmental Health

The Northern Center for Occupational and Environmental Health (COEH) and its sister centers at Los Angeles and Irvine serve government, industry, schools, health professionals, and the general public through programs and partnerships designed to deepen understanding of occupational and environmental hazards and to prevent disease, fatalities, and injuries.


If you require an accommodation for effective communication (ASL interpreting/CART captioning, alternative media formats, etc.) to fully participate in this event, please contact Michelle Meyer at (510) 642-8365 or mmeyer@berkeley.edu(link sends e-mail) with as much advance notice as possible and at least 7-10 days in advance of the event.