Avoid releasing smoke in the home

People with long-term exposure to incense may face an increased risk of cancers in the squamous cells of the respiratory tract, according to researchers at the Statens Serum Institut in Copenhagen, Denmark.

In large areas of Asia, the regular burning of incense is an integral part of their daily rituals. Incense burning is also a popular practice among some communities in the West. The study therefore has important implications on public health.

Burning incense results in the production of particulate matter, which contains compounds such as polyaromatic hydrocarbons, benzene and carbonyls, all of which are carcinogenic. In addition, condensates of incense smoke have been found to cause mutations and damage to genetic material in mammalian cells at levels even higher than tobacco smoke. Long-term use of incense in the home has also been linked to childhood leukemia and brain tumors.

The study involved the review of data from a large cohort study of 61,320 Singapore Chinese. The data covered the period 1993 to 1998 and included living conditions, diet, and lifestyle. The ages of the participants ranged from 45 to 74 at the time they were interviewed. All of them did not have any cancer, and nearly three of four used incense regularly.

A follow-up monitoring was done 12 years later in 2005. At this point, 325 participants had developed cancer in the upper respiratory tract -- or in parts of the nose, mouth and throat. Another 821 had been diagnosed with lung cancer.

There was a statistically significant association between incense use and higher risk of cancer in the upper respiratory tract, except for nasopharyngeal cancer. However, the researchers did not detect any overall effect of incense use on risk of lung cancer.

Heavy use of incense appeared to influence higher rates of cancers in the squamous cells, which line the internal and external surfaces in the body. Both smokers and nonsmokers were affected.

Heavy use, or use of incense all day, resulted in 80 percent more likelihood of developing cancers in the squamous cells of the respiratory tract compared to non-use of incense.

In response to the study results, the chief medical officer of the American Lung Association announced that incense burning will be added as a risk factor to respiratory cancer. The association stressed that this is nowhere near the danger posed by smoking a pack of cigarettes daily for 20 years, but the danger exists.

Safety Tip:

* Avoid releasing smoke in the home. Anything that downgrades air quality is generally not good for your body. Casual incense use is of little consequence.