Yes, burning incense is bad for cats but the reports are somewhat conflicting and more work is needed. Please read on for some more detail! I was reading a book by Dr Yuki Hattari, Japan’s leading cat doctor. He tells us, like any decent cat owner would, that cigarette smoking in the home carries a threefold risk of a domestic cat developing a lymphoma. He then goes on to state that it is best not to burn incense in a room frequented by your cat. That got me digging around a bit on the Internet into the health impact of burning incense in both humans and their human companions.
In general terms
In the round and in general terms, cats are sensitive to smoke and burning incense can result in upper respiratory symptoms such as congestion, sneezing and watery eyew. And if a cat has an underlying respiratory illness or is hard of breathing such as for the flat-faced breeds then incense can make matters worse. It may also trigger asthma.
Fortunately, I’m able to dig a bit deeper and refer to a scientific study carried out in 2008. The study reminds me that in Asian countries where Buddhism and Taoism are mainstream religions incense burning is a way of life. It happens on a daily basis. And there are a lot of domestic cats in these countries so I wonder whether cat guardians in these countries are considering the health implications of incense burning on their cats?
There are a multitude of potential health consequences of burning incense. Incense burning pollutes the air. There is particulate matter. These are small particles some of which are too large to penetrate the respiratory systems of humans and cats but particles less than 10 micrometres are a health risk because they can accumulate in the respiratory system. It appears that there are no studies on the impact of these particulates from incense burning. However, the addition of calcium carbonate in incense can suppress the omission of particulates by as much as 40 percent.
The gaseous emissions from incense are extensive. Carbon monoxide is emitted and it combines with haemoglobin more readily than oxygen and therefore reduces the blood’s capacity to transport oxygen.
Incense also emits sulphur dioxide and nitrogen dioxide which aggravate existing cardiovascular diseases. They have an effect on pulmonary function, respiratory illnesses and can cause lung irritation and alterations to the defence system of the lungs.
Burning incense also throws volatile organic compounds into the air. These are chemicals that have low boiling points and therefore they evaporate at room temperature. These chemicals include benzene, toluene, isoprene and xylenes. They can cause eye irritation, nose irritation, throat irritation, headaches, dizziness, asthma exacerbation, nausea and vomiting. As an extreme, they can cause cancer, kidney damage, liver damage, and central nervous system damage. Studies have concluded that the measured benzene concentrations are significantly higher than standard in buildings in Hong Kong.
Burning incense also generates aerosols and formaldehyde. Aldehydes are volatile organic compounds. They cause irritation to the skin, upper respiratory tract and eyes. Aldehydes also affect nasal mucous membranes and oral passages. They can cause a burning sensation, choking and coughing and bronchial constriction.
Formaldehyde is linked to cancer. Incense sticks have wood dust in them and studies have correlated wood dust and formaldehyde with nasal cancer. Wood which carries formaldehyde makes the formaldehyde more toxic.
The smoke emitted by incense burning contains polycyclic aromatic hydrocarbons. Taiwanese temples are polluted with incense smoke especially during festivals such as the Chinese New Year.
In India diethylphthalate is used in incense sticks as it binds the perfumes. It is emitted when the incense stick is burnt. It is a suspected carcinogen. It can injure the liver.
Second hand smoke from incense burning is harmful to human and cat health. And the volatile organic compounds are toxic to the lungs and allergenic to skin and eyes.
When the pollutants emitted from incense burning is inhaled they cause respiratory dysfunction. In addition, incense burning raises the risk of an allergic reaction and dermatological problems i.e. skin problems.
It has been suggested that incense burning can cause indoor air pollution which is akin to cigarette smoking and possibly cancer in humans and cats. Incense smoke contains various N-nitroso compounds which are “potent nervous system carcinogens”. They’re particularly dangerous when transferred from mother to embryo. There is an increased risk of brain tumour.
Although several studies have shown that there is no association between incense smoke and cancer. This information conflicts with some of what I have written above. But in conclusion, and I will quote from the study, “When incense smoke pollutants are inhaled, they cause airway dysfunction. Incense smoke is a risk factor for elevated cord blood IgE levels and has been indicated to cause allergic contact dermatitis. Incense smoke also has been associated with neoplasm. However, several conflicting reports have also been documented.”
Further studies need to be carried out. Clearly I cannot end the article without stating that there are beneficial effects of incense burning to humans. It makes them feel better but it seems that this emotional benefit is at the potential expense of feline health. Link to: Incense smoke: clinical, structural and molecular effects on airway disease.