They are considered an essential part of prayer. No Hindu puja is complete without burning an agarbatti. But now think twice before lighting that stick of incense. You might be getting more than a gentle whiff of sandalwood.

According to a group of researchers in China, burning incense could be a cancer risk! And you thought those purifying aromas were only spiritually comforting.

The Study

Scientists in South China University of Technology, tested the two most common types of incense, agarwood and sandalwood on rats.

They then found that incense-smoke is mutagenic (causes changes at the DNA level), genotoxic (causes genetic changes leading to cancer) and cytotoxic (so toxic that it kills your cells, chemotherapy is cytotoxic). Simply put, the toxins from incense smoke can make genetic mutations and changes in cells’ DNA, all of which can lead to cancer.

When compared to cigarette smoke, incense smoke was found to be more mutagenic, cytotoxic and genotoxic than the toxins released by a cigarette.

Levels of one chemical believed to cause lung cancer were 40 times higher in a badly ventilated temple in Taiwan than in houses where people smoke cigarettes.

Beyond the cancer scare, incense is actually bad for the air. If inhaled, they become trapped in the lungs, and are known to cause an inflammatory reaction.

The study published in Environmental Chemistry Letters, also finds that “burning incense creates more pollution than road traffic at a local intersection”. In the smoky temple tested in Taiwan, the incense emissions exceeded the standard “safe” levels for ambient air.

The smoke of the incense sticks analysed contained more than 64 compounds.

Doctors Advice: Don’t Burn Incense Around Children

In no way does the study imply that cigarette smoking is as harmless as burning incense. If you do light up, ensure you have good ventilation and don’t buy cheap sticks, which usually give out more pollutants.

Dr Nick Hopkinson, the medical adviser to the British Lung Foundation says people with lung disease should avoid burning incense and parents should avoid burning the sticks around children.

Smoke from any source has an effect on the lungs, and it has a particularly bad effect on developing lungs. The main cause of lung disease is cigarette smoke, but there are other types of smoke. This study shows incense smoke has toxic effects, in a laboratory setting.
– Dr Nick Hopkinson, Medical Adviser, British Lung Foundation

On an average, most people are not exposed to a lot of incense smoke. So you think. From Hindus, Christians and Buddhists, all use agarbattis while worshipping. There are more than three million religious places of worship in India alone and over 10 million marriages take place every year in this country according to the 2011 census. Now multiply the amount of smoke generated in all these places. The emissions will baffle you.