Secondhand cannabis smoke

The inhalation of smoke by nonsmokers in proximity to active cannabis users—has been a topic of interest and concern. While research is ongoing, we’ll explore what we currently know about the effects of secondhand cannabis smoke and its potential impact on nonsmokers.

1. Psychoactive Effects

What happens when you’re exposed to secondhand cannabis smoke?

• Studies have shown that nonsmokers exposed to cannabis smoke can experience mild effects of the drug. These effects are often colloquially referred to as a “contact high.”
• Memory and coordination: Nonsmokers may exhibit minor impairments in memory and coordination after exposure to secondhand cannabis smoke.
• Drug tests: Researchers measured THC levels in the blood of nonsmokers who spent time in well-ventilated spaces with cannabis smokers. While THC was detected, the amounts were well below the threshold needed to fail a drug test.

2. Health Risks

How does secondhand cannabis smoke compare to tobacco smoke?

• Cardiovascular effects: A study in rats found that one minute of exposure to secondhand cannabis smoke impaired blood vessel function similarly to secondhand tobacco smoke. The effects from cannabis smoke lasted longer than those from tobacco smoke.
• Toxins and tar: Marijuana smoke contains toxins and tar, similar to tobacco smoke. This raises concerns, especially for vulnerable populations like children and individuals with asthma.

3. Practical Considerations

What should nonsmokers be aware of?

• Ventilation matters: The level of ventilation plays a role. In an unventilated room or enclosed vehicle, extreme exposure to cannabis smoke can lead to detectable THC levels and mild intoxication.
• Legal implications: Nonsmokers who test positive for THC in urinalysis due to secondhand exposure may face legal challenges or workplace consequences.

Conclusion

While more research is needed, it’s clear that secondhand cannabis smoke is not entirely benign. Nonsmokers should be mindful of exposure, especially in confined spaces. As cannabis legalization continues, understanding the risks and taking precautions becomes crucial.

Remember, knowledge evolves, and staying informed is essential. If you have specific health concerns, consult a healthcare professional.