Burning Incense May Increase Risk of Respiratory Tract Cancer

Posted: August 26, 2008

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Friborg's team documented a total of 325 upper respiratory tract cancers (including nasal/sinus, tongue, mouth, laryngeal and other cancers) and 821 lung cancers during follow-up. Incense use was associated with a significantly increased risk of upper respiratory tract cancer (other than nasopharyngeal), but there was no overall effect on lung cancer.

The researchers also noted that the duration and intensity of incense use were associated with an increased risk of squamous cell carcinomas in the entire respiratory tract. Squamous cells cover the internal and external surfaces of the body.

According to the study data, incense use seemed to add to the increased risk of upper respiratory tract squamous cell carcinoma in smokers. It also considerably increased the risk in never smokers, which points to an independent effect of incense smoke.

The authors note that their study is the first prospective investigation on incense and cancer risk, and they stressed that incense use extends beyond the Chinese populations—it is used on a daily basis in both temples and homes in many non-Chinese, Asian communities, including those in Southeast Asia and the Indian subcontinent. Regular use also occurs in the West.

"Given the widespread and sometimes involuntary exposure to smoke of burning incense, these findings carry significant public health implications," they wrote. "Besides initiatives to reduce incense smoke exposure, future studies should be undertaken to identify the least harmful types of incense," they added.