New York, Nov 17 (IANS): Breathing second-hand marijuana smoke could damage your heart and blood vessels as much as second-hand cigarette smoke, says a new research.

Reduced blood vessel function may raise the chances of developing atherosclerosis and consequently lead to a heart attack. Atherosclerosis is the disease process that causes plaque build-up in the arteries, which narrows them and restricts blood flow.

"If you're hanging out in a room where people are smoking a lot of marijuana, you may be harming your blood vessels," said senior author of the study Matthew Springer, associate professor of Medicine at the University of California in the US.

"There is no reason to think marijuana smoke is better than tobacco smoke. Avoid them both," Springer added.

In the study, blood vessel function in lab rats dropped to 70 percent after 30 minutes of exposure to second-hand marijuana smoke.

Even when the marijuana contained no tetrahydrocannabinol (THC) - a compound in marijuana that produces intoxication - blood vessel function was still impaired.

Marijuana and tobacco smoke are chemically and physically alike.

Now that marijuana is becoming increasingly legalized in the United States, its effect on others is a growing public health concern, Springer said.

The study was presented at the ongoing American Heart Association's Scientific Sessions 2014 in Chicago, Illinois.