Burning incense is an important religious ritual for many cultures. It is also used to mask bad smells and repel mosquitoes and flies in homes.
Studies have found that temple incense-burning releases air pollutants including particulate matter and polycyclic aromatic hydrocarbons (PAHs). The latter are known to cause DNA damage and increase the risk of oxidative stress.
Many people are unaware that the burning of incense sticks creates air pollution and contributes to poor AQI. Inhaling the smoke from incense releases particulate matter, carbon monoxide, VOCs and polycyclic aromatic hydrocarbons (PAHs). These pollutants are a known cause of cardiovascular and respiratory diseases and lung cancer.
The incense industry is mainly comprised of factories that produce rolled and cored incense sticks. The support materials for these sticks are either made of bamboo or wood, which are then coated with a mix of fragrance materials and plant-based binders.
These binders are used to form the paste-like incense that can be shaped into larger coils or cored sticks. This incense is then dried before being ready to be burned. To test the pollution emissions from this type of incense, the researchers used a lab chamber equipped with an exhaust duct. Using field data and the indoor air quality model equations, they calculated emission factors for particulate matter and carbon monoxide from incense stick burning.
Many types of incense require a binder to hold and support the fragrant material in their form. Binders are often made from natural plant sources. For example, the viscous mucilage in the bark of the tabu-no-ki (Machilus thunbergii) tree is commonly used as wet binding powder for indirect-burning incense in Japan. Dry binding powder, such as ground larch (Larix kauri) or the woody powder of the makko (Michaelinen), is also used.
Incense smoke contains particulate matter that can irritate the nose, eyes and throat, and is a respiratory stimulant in high concentrations. It also contains carbon monoxide, which combines with hemoglobin to deprive the brain and heart of oxygen, leading to headaches, weakness and fainting.
Regular burning of direct-burning incense produces polycyclic aromatic hydrocarbons, which have been linked to cancer. Several studies show that the amount of PAHs produced by burning incense varies with the amount of incense burned and with the temperature at which it burns.
Human Health Impact
Many cultures use incense for hygienic and spiritual purposes. When incense is burned in closed spaces without ventilation, it releases particulate matter into the air that can irritate the lungs and cause other health problems. This can be especially true for those who regularly inhale incense smoke.
Incense is produced in two primary forms: whole and kneaded. The former is burnt directly on coal embers to produce short-term intense fragrances, while the latter uses a binder to hold incense blend materials together and allow the scents to mellow. Much Arabian incense, called bukhoor or bakhoor, is of this type. Japan also has a long tradition of making kneaded incense, called neriko or awaseko.
Both types of incense emit pollutants when they are burned, including particulate matter (PM2.5), carbon monoxide, and carbon dioxide. The pollutants can be dangerous for children and unborn babies, as they can cause respiratory irritation, asthma, or even cancer. To minimize emissions, temples may need to consider using mist spray geo-engineering, which can reduce PM2.5 and other pollutants.
Burning incense sticks creates harmful air pollutants including particulate matter, carbon monoxide and volatile organic compounds like benzene. The pollutants are released when the incense is burned, and they can lead to respiratory problems such as coughing and sneezing for people who regularly use incense.
Incense is made from a variety of materials that include resins, wood, tree branches and roots, seeds, and herbs. It can be found in various forms, from whole, raw ingredients to powdered or granulated products that are burned on coal embers.
These ingredients can be sourced from natural or synthetic sources. However, the production process of incense requires many fossil fuels that are a concern for the environment. Using renewable resources for incense production would reduce the impact on the environment by reducing dependence on non-renewable energy and fuels. It also allows for the growth of a sustainable economy, promoting fair trade and helping to build up local communities. As an added benefit, the use of incense could be a healthier alternative to other indoor air fresheners such as aerosol sprays that can increase indoor pollutants.