Hookahs are not harmless, in spite of what teens may think

Q: You recently wrote about e-cigarettes not being safe for teens. What about hookahs? I don't completely understand what they are. Are they OK for my teen? I think he might be smoking them.

A: A hookah is a water pipe that people use to smoke a specially made tobacco. Often the tobacco used in hookahs is flavored, which makes smoking it more attractive to some people.

A hookah uses coal to burn the tobacco. This creates either smoke or a vapor that is inhaled through a tube. People usually smoke a hookah as a group, passing the mouthpiece from one person to another.

Hookah smoking is on the rise among youths. According to a 2014 study in the journal Pediatrics, 18 percent of high school seniors have smoked a hookah.

Hookahs have been around for centuries. In ancient Persia and Asia, smoking a hookah was considered an aristocratic and elegant thing to do. Perhaps because of this reputation - and because it's an ancient practice - many people think that it isn't as dangerous as smoking cigarettes. But it is just as dangerous, if not more so.

The smoke you inhale from a hookah contains the smoke from both coal and tobacco, which are full of toxins and cancer-causing substances.

In fact, tobacco smoke contains more than 7,000 chemicals, including hundreds that are toxic and about 70 that can cause cancer. The smoke also has nicotine. Nicotine, by itself, does not cause cancer - but it is the chemical that makes people addicted to tobacco.

Smoking a hookah increases all the same health risks as smoking a cigarette. This includes cancers of the mouth, esophagus, stomach, lung, bladder and other parts of the body. It can lead to lung disease, cardiovascular disease, infertility, and low birth weight in the babies of women who smoke hookahs.

Also, because the mouthpiece is often passed from person to person, there is the risk of passing infection.

Since hookahs are smoked as a group, the smoking session may last a while, which can lead to more exposure to the toxins. A person smoking a hookah with a group of other people not only is exposed to the smoke he deliberately sucks into his body through the tube. He is also exposed to smoke in the air around him, which typically is heavy.

As a result, an hour of hookah smoking exposes someone to as much as 200 times the smoke as smoking one cigarette.

Smoking a hookah may be more appealing to teens than smoking cigarettes. First, there's the novelty of the device itself. Second is the fact that it's a group activity - and it's particularly important for teens to feel like part of a group.

Your teen may think that smoking a hookah is just something fun to do with his friends.

Tell him about the health risks involved. Be sure to let him know that he and his friends could end up putting their health, even their lives, in danger if they continue the practice.

• Dr. Komaroff is a physician and professor at Harvard Medical School. For questions, go to AskDoctorK.com.