New studies show sandalwood incense smoke releases fine particles and toxic chemicals linked to lung cancer and respiratory diseases
Medical experts and recent scientific studies are raising alarms over the health risks of burning incense sticks, commonly used in homes and places of worship. Pulmonologists warn that the smoke and fragrance released from sandalwood incense may be as harmful as cigarette smoke, particularly to the lungs.
Fine Particles Comparable to Cigarettes
A growing body of research has shown that when a single incense stick is burned, it releases fine particulate matter (PM2.5 and ultrafine PM1) in concentrations comparable to — and in some cases greater than — those produced by a cigarette. These microscopic particles can penetrate deep into the lungs, triggering inflammation, asthma, chronic obstructive pulmonary disease (COPD), and even lung cancer.
A 2023 chemical analysis published in Atmospheric Chemistry and Physics found that incense smoke contains over 300 volatile organic compounds (VOCs) including benzene, toluene, formaldehyde, and polycyclic aromatic hydrocarbons (PAHs) — all known or suspected carcinogens. Researchers concluded that even so-called “smokeless sandalwood” sticks produced hazardous aromatic compounds that accumulate indoors.
Medical Experts Voice Concern
Respiratory specialists emphasize that the health risks from incense smoke are often underestimated.
“People assume incense is harmless because it is linked with tradition and spirituality. But in reality, the smoke contains toxins and fine particles similar to those in tobacco smoke,” said Dr. Arun Mehta, a pulmonologist based in New Delhi.
“Continuous indoor exposure — especially in poorly ventilated homes — can raise the risk of chronic bronchitis, reduced lung function, and lung cancer.”
Several hospital-based studies in Taiwan and Singapore found that long-term incense use was linked with higher rates of upper respiratory cancers and measurable declines in lung function among temple workers and frequent users.
More Dangerous in Confined Spaces
Unlike cigarette smoke, which is usually inhaled by the smoker, incense smoke fills enclosed spaces and can expose entire families, including children and the elderly. Experts stress that this passive exposure could be especially dangerous for vulnerable groups.
The World Health Organization (WHO) already classifies household air pollution from solid fuels and biomass burning as a major health hazard. Public health researchers argue that incense smoke should be considered in the same category.
What People Can Do
Doctors recommend reducing exposure by:
Burning incense less frequently.
Using well-ventilated spaces or outdoor areas.
Considering alternatives such as essential oil diffusers or low-smoke incense.
While incense sticks remain an integral part of cultural and religious practices, experts urge the public to recognize the hidden dangers. “Incense smoke may smell pleasant, but prolonged exposure can have lifelong consequences,” said Dr. Mehta.
