Potential exposures associated with indoor marijuana growing operations.

Area of Science:

• Environmental Health
• Occupational Safety
• Industrial Hygiene

Background:

• Indoor marijuana grow operations (IMGOs) present unique environmental challenges for first responders.
• Assessment of airborne contaminants and chemical exposures is crucial for ensuring responder safety.

Purpose of the Study:

• To determine potential exposures of first responders to airborne fungal spores, volatile organic compounds (VOCs), carbon dioxide (CO2), carbon monoxide (CO), and delta-9-tetrahydrocannabinol (THC) in 30 IMGOs.
• To identify chemicals used in IMGOs and assess their toxicity.
• To evaluate fungal spore levels and species shifts during IMGO investigations.

Main Methods:

• Conducted environmental sampling within 30 IMGOs alongside law enforcement investigators.
• Collected samples for airborne fungal spores, VOCs, CO2, CO, and surface/hand-wipe delta-9-tetrahydrocannabinol (THC).
• Identified chemicals used, including pesticides and fertilizers, and analyzed spore counts and species using impactor plates and 400-hole impactors.

Main Results:

• Chemicals used were primarily pesticides and fertilizers with low toxicity.
• Carbon monoxide (CO) levels were not elevated despite CO2 enrichment processes.
• Elevated fungal spore levels, particularly Penicillium sp., were found indoors, increasing significantly during plant removal (exceeding 50,000 spores/m³).
• Delta-9-tetrahydrocannabinol (THC) was detected on surfaces and responders' hands but at non-toxic levels.

Conclusions:

• First responders may be exposed to high fungal spore concentrations in IMGOs, comparable to mold remediation environments.
• Respiratory protection is recommended for responders during IMGO investigations, especially during plant removal.
• While THC and chemical exposures were not acutely toxic, fungal spore levels pose a significant respiratory risk.