Literature Review: "One Minute of Marijuana Secondhand Smoke Exposure Substantially Impairs Vascular Endothelial Function"
This study looks into the potential harmful effects of second-hand cannabis smoke in comparison to second-hand tobacco smoke. It clearly shows that cannabis smoke impairs arterial dilation reflex response in the same fashion as second-hand cigarette smoke. The study results do support that limiting secondhand smoke exposure overall is a good idea and suggests that whole-plant usage may not be the best choice for patients taking medications with vasodilator effects.
What it doesn't clearly discuss is that this seems to be an effect of smoke, period. It has nothing to do with THC, although they did control for cannabinoids. The authors seem to be implying that laws should be rewritten to limit all smoke exposure, regardless if tobacco or cannabis. A quick reading of this study seems to imply that this effect is somehow particular to cigarettes or cannabis but a closer reading shows that if you burn anything and force rats to inhale it, the smoke will impair vasodilation. So it irritates me somewhat that this is a smoke study dressed up as a cannabis study.