Joss sticks as bad as cigarettes, says study
Staff and people who pray at temples and shrines filled with smoke from joss sticks are prone to lung cancer due to long-term exposure, a study by Chulabhorn Research Institute has found. The study was conducted over the course of the past two years at three famous temples in Ayutthaya, Chachoengsao and Samut Prakan.
The researchers collected blood and urine samples from 40 people working in the temples to compare them with samples from 25 people living in a joss stick smoke-free environment.
Manoon Leechawengwong, a research team member, said joss stick smoke contains high level of cancer-causing substances, including benzene, butadiene and benzo(a)pyrene.
Air quality measured at the smoke-filled temples found dangerously high levels of these carcinogenic substances, said Dr Manoon.
According to the study, released yesterday, the air at these temples contained 94 microgrammes per cubic metre (ug/cu m) of benzene, against a safety standard of 1.7 ug/cu m, 11 ug/cu m of butadiene against a safety level of 0.33, and 2.52 nanogrammes per cubic metre of benzo(a)pyrene, the safety standard for which is at 0.25.
''One joss stick creates the same amount of cancer-causing chemicals as one cigarette,'' said Dr Manoon.
Urine tests on 40 temple staff also detected monohydroxybutenyl-mercapturic acid, an indicator of cancer-causing chemicals in the body, he said.
Moreover, the study found that the abilities of the bodies of the people exposed to a joss stick smoke-concentrated environment to repair damaged DNA was lower than among other groups.
''Crowded shrines in Yaowarat are of the most concern since the temples and shrines are filled with smoke all day, every day. Traffic pollution has worsened the air quality in Yaowarat,'' he said.
The situation could lead to residents developing cancer, he warned.
To ease air pollution from joss sticks, the doctor suggested that temple staff and people who pray blow them out after prayers are finished.
Smoke from joss sticks also contributes to global warming, the research found.
One tonne of joss sticks burned reportedly emits 325 kilogrammes of carbon dioxide and 7.2 kg of methane.