New research suggests that despite declines in the number of youths who smoke cigarettes, hookah or water pipe use continues to rise among Canadian youth.

Researchers at the University of Waterloo found that almost one in four high school seniors try smoking hookah.  Their study estimates that more than 78,200 youth are current water pipe users.

"While we can celebrate a continued slow decline in cigarette use across the country, water pipes are bucking the trend," Leia Minaker, who conducted the study funded by the Canadian Cancer Society, said in a statement.

Water pipes work by bubbling tobacco smoke through water, leading many users to believe that they carry less risk than cigarettes.

For the study, which analyzed data from the national 2012-2013 Youth Smoking Survey, found that over a third of youth believe it is less harmful to smoke tobacco in a water pipe than smoking a cigarette.

"The idea that water pipes are somehow less harmful than cigarettes is a dangerous misperception," Minaker said in a statement. "Since most water pipe smoking sessions last much longer than a cigarette, water pipe smokers may absorb higher concentrations of the same toxins as in cigarette smoke."

Water pipes join a growing number of products marketed to youth using flavored tobacco. The survey found that among students who reported using water pipes, about half used flavored products.

"The tobacco industry continues to add candy, fruit and other flavors to tobacco products to attract young people. Restricting flavors in tobacco products is an important part of a comprehensive tobacco control strategy," Minaker said.

The study also found that water pipe use increases significantly by grade, with boys more likely than girls to try hookah during their high school years. Youth with higher amounts of weekly spending money have significantly higher odds of using water pipes. About 14 percent of grades 9 to 12 students in Canada have tried water pipes, up from 10 percent in 2010.

The findings are detailed in the journal Cancer Causes and Control.