The increased risk was seen in smokers and non-smokers , indicating an independent effect of incense . Previous research has shown that burning incense produces cancer-causing substances such as benzene , although the new study did not show increase in the over all risk of lungs cancer . The American Lung association says it will add incense burning to its list of risk factor for lung cancer . If you regularly burn it, avoid doing so in room where you spend the most time , and ensure that your room is ventilated .