Hippies beware: incense poses cancer risk

Incense releases large amounts of smoke containing particulate matter that gets caught in the lungs, as well as possible carcinogens such as polyaromatic hydrocarbons (PAHs), carbonyls and benzene.

Indoor concentrations of particulate matter from burning incense has been found to far exceed outdoor air quality standards, and can potentially produce more particulate matter than second-hand tobacco smoke, previous studies have shown.

Burning incense almost doubled the risk of squamous cell carcinomas in the upper respiratory tract, such as the nose and sinuses, tongue, mouth and larynx, said the researchers led by Dr. Jeppe Friborg of the epidemiology department at Statens Serum Institut in Copenhagen, Denmark.

Their findings are published in the Oct. 1 issue of the journal Cancer.

"Given the widespread and sometimes involuntary exposure to smoke of burning incense, these findings carry significant public health implications," the study's authors concluded.

"Besides initiatives to reduce incense smoke exposure, future studies should be undertaken to identify the least harmful types of incense."