PITTSBURGH, Pa. (CBS) — Some smokers looking for an alternative have turned to hookahs, but a new study has found hookahs may be more dangerous than cigarettes.

Researchers at the University of Pittsburgh School of Medicine found hookah exposes the smoker to more tar, nicotine and carbon monoxide than a cigarette.

“Our results show that hookah tobacco smoking poses real health concerns and that it should be monitored more closely than it is currently,” said lead author Brian A. Primack, M.D., Ph.D., assistant vice chancellor for health and society in Pitt’s Schools of the Health Sciences.

Researchers note that comparing a hookah smoking session to smoking a single cigarette is a complex comparison to make because of the differences in smoking patterns. They say a cigarette smoker may smoke 20 cigarettes a day, while a hookah smoker may only participate in a few hookah sessions each day.

Dr. Primack says, “It’s not a perfect comparison because people smoke cigarettes and hookahs in very different ways. We had to conduct the analysis this way—comparing a single hookah session to a single cigarette—because that’s the way the underlying studies tend to report findings. So, the estimates we found cannot tell us exactly what is ‘worse.’ But what they do suggest is that hookah smokers are exposed to a lot more toxicants than they probably realize. After we have more fine-grained data about usage frequencies and patterns, we will be able to combine those data with these findings and get a better sense of relative overall toxicant load.”

A recent national youth tobacco survey found hookah use doubled, while cigarette use dropped.