Health and Environmental Risks of Incense Smoke: Mechanistic Insights and Cumulative Evidence

J Inflamm Res. 2022 Apr 26:15:2665-2693. doi: 10.2147/JIR.S347489. eCollection 2022.


Incense burning is practiced alongside many sacred rituals across different regions of the world. Invariable constituents of incense brands are 21% (by weight) herbal and wood powder, 33% bamboo stick, 35% fragrance material, and 11% adhesive powder. Major incense-combustion outputs include particulate matter (PM), volatile organic content, and polyaromatic hydrocarbons. The relative toxicity of these products is an implicit function of particle size and incomplete combustion, which in turn vary for a specific incense brand. Lately, the attention given to the Air Quality Index by international regulatory bodies has created concern about mounting PM toxicity. The uncharacteristically small physical dimensions of these entities complicates their detection, and with no effect of gravity PM fractions rapidly contribute to oxidative stress, enhancing random biochemical reactions upon being inhaled. Incense burning generates four times the PM extent (45 mg•g-1) of cigarettes (~10 mg•g-1). Several poisonous gases, such as CO, CO2, NO2, and SO2, and the unavoidable challenge of disposing of the burnt incense ash further add to the toxicity. Taken together, these issues demonstrate that incense burning warrants prompt attention. The aim of this article is to highlight the toxicity of incense-combustion materials on the environment and human health. This discussion could be significant in framing future policy regarding ecofriendly incense manufacture and reduced usage.

Keywords: burnt incense ash; incense combustion; oxidative stress; particulate matter; polyaromatic hydrocarbons; volatile organic content.

Publication types

  • Review

Grants and funding

The authors gratefully acknowledge the Deanship of Scientific Research, King Khalid University (KKU), Abha-61421, Asir, Kingdom of Saudi Arabia for funding this research work under the grant number RGP.2/140/43. This work was funded by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) of the Republic of Korea (No. 20210310100020).