Health Impacts of Indoor Air Pollution from Incense Burning

Incense burning is a widespread ritual in many cultures, yet it releases a complex mixture of fine particulate matter, gaseous by-products and volatile organic compounds into the indoor environment. Prolonged inhalation of these pollutants has been linked to respiratory symptoms such as wheezing, asthma exacerbation and allergic airway inflammation. Evidence also points to systemic effects including endothelial dysfunction, increased risk of peripheral arterial disease and elevated cardiovascular mortality. Emerging data suggest neurocognitive consequences, with pollution-induced oxidative stress and inflammatory cascades contributing to neuronal injury. Molecular studies reveal activation of mitogen-activated protein kinases and generation of reactive oxygen species in exposed cells, while organic species such as benzene, toluene and furfural drive secondary aerosol formation and long-range transport. Given the global prevalence of incense use indoors, this body of research underscores the need for ventilation guidelines, development of lower-emission products and public health policies to reduce exposure.

Research from Nature Portfolio

Recent studies have demonstrated that older adults who engage in weekly indoor incense burning exhibit accelerated cognitive decline over a three-year period. Detailed neuropsychological assessments revealed deficits in memory, attention and executive function at baseline and follow-up. Concurrent magnetic resonance imaging showed reduced connectivity within the default mode network, a brain circuit critical for higher-order cognition. These effects were most pronounced in individuals with comorbid diabetes, hyperlipidaemia or white matter hyperintensities, indicating that vascular risk factors potentiate the neurotoxic impact of incense-derived air pollution.

Health Impacts of Indoor Air Pollution from Incense Burning publication trend

The graph below shows the total number of articles in health impacts of indoor air pollution from incense burning across all publications each year (not limited to Nature Index journals).

Technical terms

Particulate matter (PM₂.₅): Airborne particles with aerodynamic diameter ≤ 2.5 µm that penetrate deep into the lung.

Volatile organic compounds (VOCs): Organic chemicals that readily evaporate at room temperature, contributing to indoor air pollution and secondary aerosol formation.

Reactive oxygen species (ROS): Highly reactive molecules derived from oxygen that can damage cellular components and trigger inflammation.

Secondary organic aerosol (SOA): Particles formed in the atmosphere by the oxidation of VOCs, contributing to fine particulate burden.

Default mode network (DMN): A network of interacting brain regions active during rest and involved in memory, self-referential thought and planning.

References

1. Incense Use and the Risk of Chronic Limb-Threatening Ischemia Among Middle-Aged and Older Adults in the Singapore Chinese Health Study. Environmental Health Perspectives (2025).
2. Tanshinone IIA suppresses burning incense-induced oxidative stress and inflammatory pathways in astrocytes. Ecotoxicology and Environmental Safety (2023).
3. Molecular fingerprints and health risks of smoke from home-use incense burning. Atmospheric Chemistry and Physics (2023).
4. Incense Use and Cardiovascular Mortality among Chinese in Singapore: The Singapore Chinese Health Study. Environmental Health Perspectives (2014).
5. Incense smoke: clinical, structural and molecular effects on airway disease. Clinical and Molecular Allergy (2008).
6. Indoor incense burning impacts cognitive functions and brain functional connectivity in community older adults. Scientific Reports (2020).