Scientists: Second-Hand Pot Smoke Damages Blood Vessels

Second-hand smoke from marijuana is more damaging than previously thought, new research shows, according to CBS News.

A study from the University of California San Francisco found that second-hand pot smoke impaired blood vessel function by 70 percent after exposure for about 30 minutes by lab rats — acting in the same way tobacco smoke does, CBS noted. Such impairment is a precursor to hardening of the arteries, which can cause a heart attack, the researchers said.

"Smoke is smoke. Both tobacco and marijuana smoke impair blood vessel function similarly," the study's senior author and UC associate professor of medicine Matthew Springer told CBS.

"People should avoid both, and governments who are protecting people against secondhand smoke exposure should include marijuana in those rules," Springer added.

A U.S. Surgeon General's report for 2014 found about 34,000 people had died prematurely from second-hand tobacco smoke, CBS noted. The American Lung Association has noted that marijuana smoke "contains a greater amount of carcinogens than tobacco smoke."

For that reason, concern among the medical community rises over pot's health impacts as more states vote to legalize or decriminalize marijuana use.

Twenty-three states permit medical marijuana. Supporters predict the issue will go the same way as alcohol prohibition, although some amendments have lost in recent elections including a hard-fought ballot measure before voters in Florida earlier this month, USA Today noted.

The District of Columbia, Alaska and Oregon approved legalization in the recent midterm election, according to Rolling Stone magazine.

Related stories:

• UN: Legalized Pot in US States Violates International Law
• Pot Study: Brain Changes From Marijuana May Include Shrinkage