Burning incense contributes to indoor air pollution and could be harmful to human health, according to researchers in the Gillings School of Global Public Health at the University of North Carolina at Chapel Hill.

Authors identified and measured the particles and gases emitted from two kinds of incense typically used in homes in the United Arab Emirates (UAE). Burning incense is particularly popular in Arabian Gulf countries, according to researchers.

The team analyzed both particulate concentrations and levels of gases such as carbon monoxide, sulfur dioxide, oxides of nitrogen and formaldehyde. They placed human lung cells 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 cells exhibited an inflammatory response similar to that of lung cells exposed to cigarette smoke, according to the authors, who recommended implementing better ventilation in UAE homes when incense is burned, such as opening a door or window to improve air flow. They also suggested using alternatives to briquettes frequently are used to ignite and burn the incense.