Secondhand marijuana smoke impairs blood vessel functioning
The American Heart Association found that blood-vessel function in lab rats dropped by 70% after 30 minutes of exposure to secondhand marijuana smoke, and did not return to normal even after 40 minutes. The rats also suffered the same effects even if the marijuana contained no THC. The conclusion is that with continued exposure to marijuana smoke, a bystander could suffer impaired lung and blood-vessel function.
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