Incense Stick: An Overlooked Source of Health Hazard

Development and application of the Ames test using a direct-exposure module: The assessment of mutagenicity of incense and sidestream cigarette smoke

We had previously developed an improved Ames module to directly determine the mutagenicity of gaseous formaldehyde (HCHO) and toluene without liquid extraction. This study further evaluated the suitability and sensitivity of this module on whole and real polluted air samples. For this, two common brands of stick incense (A and B) and cigarettes (A and B) were harvested, and various types of incense smoke (IS) and sidestream cigarette smoke (SCS) samples were generated by lighting 3, 6, 12, 24, 30, or 36 incense sticks, and by lighting 1, 2, or 3 cigarettes, respectively, in an acrylic box. CO₂ , CO, total volatile organic compound (TVOC), PM_1.0, and HCHO concentrations in the air samples were determined, and all air samples did not partially fit the requirements of the air quality standards. The smoke samples were then directly exposed to TA100 for 10, 20, 30, or 60 min in our exposure module. Exposure to IS (brand A) for 30 to 60 min and exposure to IS (brand B) for 60 min led to statistically (p < 0.05) weak (below the twofold rule) but dose-dependent mutagenic activities either with or without metabolic activation. Furthermore, a short-term exposure (10-60 min) to SCS (brands A and B) displayed statistically significant (p < 0.05) direct-acting, indirect-acting, time- and dose-dependent mutagenic activities. Furthermore, our data also support that the liver S9 enzyme could enhance the mutagenic activities in most IS and SCS samples. This study confirmed that the modified Ames module can be applied to directly detect the mutagenic activities of real polluted air samples.

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

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.