The Internet is replete with home videos of teenagers dancing, goofing around, and delivering grand soliloquys on such subjects as school, peer pressure, boys and girls, and even the state of the union.

But with the wider emergence of YouTube and the mobile Web in recent years, teenagers have been posting and sharing some unhealthy behaviors. In so-called "thinspiration" videos, teenagers coach others in the ways of anorexia nervosa and bulimia, offering tips on vomiting as well as weight-loss encouragement. And a new study from Switzerland shows that 22 percent of teenagers, mostly girls, are posting sexually explicit photos and videos of themselves online, in mostly a bid for attention and self-esteem researchers say.

Now, the "Cinnamon Challenge" is gaining more attention from grownups with a write-up in May's issue of the journal Pediatrics, warning of potential long-term health risks to the fad, aside from an immediate risk of aspiration. In the challenge, an adolescent or teenager attempts to swallow a spoonful of cinnamon, invariably coughing and choking for the amusement of the audience.

"Typically, a video reveals a group of adolescents watching as someone taking the challenge begins coughing and choking when the spice triggers a severe gag reflex in response to a caustic sensation in the mouth and throat," said Amelia Grant-Alfieri, a pediatrics researcher at the University of Miami.

Though harmless when used to spice food, cinnamon can be dangerous when ingested in large quantities. The spice is comprised of cellulose fibers that neither dissolve nor biodegrade if aspirated into the lungs. Although researchers have conducted no human studies, several animal studies show that intratracheal exposure to the spice may cause granulomata, interstitial fibrosis, alveolar histiocytosis, alveolar lip proteinosis, and alveolar cell hyperplasia.

Kids with broncho-pulmonary diseases, such as asthma, may be particularly susceptible to injury, the researchers said. The cinnamon challenge has brought at least 30 to the emergency room in recent years with poison control centers in the United States receiving 51 cinnamon-related calls in 2011 and 178 during the first half of last year.

"Given the allure of social media, peer pressure, and a trendy new fad, pediatricians and parents have a 'challenge' of their own in counseling tweens and teens regarding the sensibilities of the choices they make and the potential health risks of this dare," the study authors wrote.

The study received support by the US Department of Health and Human Services, the National Center for Toxicological Research, the L. Coulter Foundation, the Batchelor Foundation, and the National Institutes of Health.