A recent study finds that burning incense generates indoor air pollutants that may cause inflammation in human lung cells.
Previous studies, some by co-author Karin B. Yeatts, research assistant professor of epidemiology and other University of North Carolina (UNC) colleagues, have associated incense smoke with a number of health problems, including eye, nose, throat and skin irritation; respiratory symptoms, including asthma; headaches; exacerbation of cardiovascular disease; and changes in lung-cell structure.
Indoor air pollution is an international health concern. The World Health Organization estimates that more than 1 million people a year die from chronic obstructive respiratory disease (COPD), primarily a result of exposure to pollutants from cook stoves and open hearths. Burning incense releases similar pollutants, including carbon monoxide.
In the current study, the authors identified and measured the particles and gases emitted from two kinds of incense typically used in UAE homes.
The testing was done over three hours, the typical timeframe during which incense is burned, in a specially designed indoor environmental chamber with a concentration of smoke that might be present in a typical UAE living room.
The researchers analyzed both particulate concentrations and levels of gases such as carbon monoxide, sulfur dioxide, oxides of nitrogen and formaldehyde.
Human lung cells were placed in the chamber to expose them to the smoke, then incubated for 24 hours to allow particulates to settle and the cells to respond.
The resulting inflammatory response, a hallmark of asthma and other respiratory problems, was similar to that of lung cells exposed to cigarette smoke.
Incense is burned weekly in about 94 percent of households in the UAE as a cultural practice to perfume clothing and air and to remove cooking odors.
Since people there spend more than 90 percent of their time indoors, researchers said, indoor air pollution has become a source of increasing concern.
Adding to the concern is that charcoal briquettes frequently are used to ignite and burn the incense. That adds significantly to potentially harmful levels of carbon monoxide and other pollutants, they said.
The study is published in the journal Science of the Total Environment.