Danish researchers say long-term exposure to burning incense can raise the risk of cancers in the upper respiratory tract but not necessarily the lungs. They interviewed 61,000 Singapore Chinese between the ages of 45 and 74 who were cancer-free when the study began. They found exposure to burning incense nearly doubled the risk of cancer developing in the nasal or sinus area, as well as the tongue, mouth, and larynx.
There was no overall increased risk in lung cancer.
The findings will be published in the October issue of Cancer.