5 Surprising Reasons To Reconsider Burning Incense Indoors
Burning incense can release toxic air pollutants and worsen cognitive health.
Posted August 14, 2021 Reviewed by Vanessa Lancaster
Key points
- Research showed that indoor incense burning was associated with worse cognitive performance and decreased brain connectivity over three years.
- A 2020 study found that burning incense indoors can facilitate the transmission of the SARS-CoV-2 virus.
- Researchers found that incense cones had a higher probability of being more polluting than incense sticks depending on quality and manufacturer.

Burning incense is often a calming and enjoyable scent in yoga studios, spas, temples, and homes.
However, new research has found some surprising health reasons to reconsider the health risks of burning incense indoors–it can worsen the transmission of the SARS-CoV-2 virus and release toxic air pollutants that have been linked to worsening brain and cognitive health. Here are five surprising health reasons about the harmful effects of burning incense indoors from new scientific research.
1. Indoor incense burning has been linked to worsen brain health.
Recent research published in the journal Nature in 2020 has found that indoor incense burning was associated with worse cognitive performance and decreased brain connectivity over three years. The study measured cognition through detailed neuropsychological testing of 515 older adults and found that those exposed at least weekly to indoor incense burning had worse cognitive performance and decreased brain connectivity at three years. Air pollutants released from incense smoke have been associated with accelerated cognitive aging, intellectual decline, and an increased risk for Alzheimer’s Disease and vascular dementia.
2. Burning incense indoors can increase the transmission of viruses such as the SARS-CoV-2 virus, which causes COVID-19, and has other health risks.
A study published in 2020 suggested that burning incense indoors can facilitate the transmission of the SARS-CoV-2 virus since incense puts coarse and fine particles into the air. Previous studies have found that burning incense can be linked to health issues, including blood pressure issues in pregnant women and associated with motor delay in babies.
3. Burning incense indoors has been linked to poor air quality, including concerning levels of benzene and formaldehyde.
Another recent study published in The International Journal of Environmental Research and Public Health found that burning incense cones/sticks indoors resulted in benzene and formaldehyde, and other pollutants at higher than the guidelines recommended by the World Health Organization. Researchers found that a host of VOCs or volatile organic compounds were released into the air from incense.
4. Mosquito-repellent incense can release formaldehyde.
Mosquito-repellent incense has been known to release formaldehyde into the air. Researchers found about 10-20% of the air pollutants from the incense was formaldehyde. The good news is that burning such incense outdoors can help reduce the amount exposed to these toxic pollutants.
5. Incense cones appear to be more likely problematic for air pollution compared to incense sticks.
Researchers found that incense cones had a higher probability of being more polluting than incense sticks, though this may vary by quality and manufacturer of the incense. Researchers acknowledge that incense is one of many products that can release VOCs, including scented candles and perfumes. Health risks are related to the overall amount of exposure to such chemicals.
The study recommends that, given these health risks of indoor incense burning, children and anyone with respiratory illnesses, such as asthma or COPD, should avoid spaces with incense, especially in indoor areas with poor ventilation.
People who would like to continue to enjoy the ritual or calming effects of burning incense can help reduce their health risks by using strong indoor air ventilation, limiting the amount of time or size of burning incense, or can opt to burn incense outdoors.
Marlynn Wei, MD, PLLC Copyright © 2021