Hookahs, or water pipes, and the tobacco used in them may be considered "the first new tobacco trend of the 21st century" and may be less harmful than cigarettes.

In new research presented at a meeting of the American Chemical Society, hookah tobacco and smoke contain lower levels of four toxic metals than those found in cigarettes.

"Any form of smoking is dangerous, and our studies on toxic metals in hookah smoke are taking the first steps toward the necessary animal and human studies that will establish a clearer picture of the relative dangers of hookah and cigarette smoking," Joseph Caruso, Ph.D., who led the study, said in a statement. "It is very difficult to compare hookah smoking with cigarette smoking because they are done so differently."

A team of scientists collected 12 different varieties of hookah tobacco made in the U.S. and Middle East and broke them down to liquid form. Test results showed that hookah tobacco contained fewer toxic metals, such as arsenic, lead, cadmium and chromium, than those in cigarette tobacco.

While some believe the difference lies in filtering smoke through water, Caruso said his team’s findings point to the composition of shisha itself. The specially prepared tobacco for water pipes contains molasses, honey and flavoring agents and lower levels of toxic metals. Caruso’s team did not detect excess amounts of the toxic metals in the hookah water.

Despite the recent findings, Caruso said there are difficulties comparing the two kinds of tobacco. Previous studies have shown that a typical hourlong hookah smoking session involves 200 puffs – equivalent to five to 10 packs of cigarettes, according to the World Health Organization. An average cigarette smoke takes 20 puffs.

In April, a study conducted by the University of California San Francisco showed that hookah smoke contained different kinds of harmful toxins that expose smokers to heart or respiratory conditions, and to higher levels of benzene, long associated with leukemia risk.

“People want to know if it is a lesser health risk if they switch from cigarettes to smoking a water pipe on a daily basis,” UCSF research chemist Peyton Jacob, said in a statement. “We found that water-pipe smoking is not a safe alternative to cigarette smoking, nor is it likely to be an effective harm-reduction strategy.”

A hookah, also known as narghile, shisha and goza, is a water pipe with a smoke chamber, a bowl, a pipe and a hose. Specially made tobacco is heated, and the smoke passes through water and is then drawn through a rubber hose to a mouthpiece.

“Young people are very interested in it,” Ryan Saadawi, the lead graduate student on an American Chemical Society study examining the effects of hookah smoking, told Vice.com. “Cherry apple and bubble gum are more enticing than Marlboro Red.”