Long-Term Incense Exposure Increases Risk of Respiratory Cancers

Burning incense may make your home smell nice, but a new study finds long-term exposure can increase the risk of developing cancers of the respiratory tracts, said researchers.

A 12-year study that followed more than 61,000 ethnic Chinese between the ages of 45 to 74, living in Singapore, found that regularly burning incense nearly doubled the risk of developing various forms of respiratory cancers including mouth, nasal/sinus and tongue cancers amongst others.

All study subjects were cancer-free at the outset. They were asked to answer a series of questions ranging from their lifestyle to eating habits and details about their exposure to incense such as how frequently they burned incense and for how long – (i.e. typically all day or during the evening.)

Over the duration of the study, 325 participants developed oral, nasal or throat cancers and 821 developed lung cancer.

Participants who used incense all day or night were 80 percent more likely than that of non-users to develop cancers of the entire respiratory tract.

Researchers determined that incense use was linked with a statistically significant higher risk of cancers of the respiratory tract, excluding that of nasopharyngeal cancer.

Participants who regularly used incense in their home showed higher rates of a type of cancer known as squamous cell carcinoma, the second most common form of skin cancer. The risk was noted in both smokers and non-smokers.

Incense is derived from fragrant plant materials such as roots, essential oils and flowers. Previous studies have found that the practice of burning incense can produce polyaromatic hydrocarbons and benzene, potentially cancer-causing substances.

However, until now, no studies have linked the practice of burning incense to increased risk of cancer, according to researchers.

“Incense burning should be used with extreme caution based on results provided by several experimental studies that have shown incense smoke contains carcinogenic substances," said Dr. Jeppe Friborg, of the department of epidemiology research at Statens Serum Institute.

Researchers say more studies are needed to determine if different types of incense are linked with different degrees of cancer risks.

The study findings are published in the medical journal Cancer. #