Like most other alternative remedies and rituals there are also a wealth of bizarre claims going around burning incense sticks. An often seen passage on sites promoting incense as a health benefit is the Ten Virtues of Incense, as written by an anonymous sixth-century monk. Let's dissect a few of these claims...
1. Incense brings communication and the transcendent.I won't go into claim one too much because the criteria for 'transcendent' is far too vague, as I'm sure you well know. I don't know about you but I don't tend to experience any superhuman abilities or talents whenever I'm burning a stick of eastern dragon or witchdoctor - relaxation and calm, sure, but nothing out of the ordinary. Who knows, maybe the laws of physics could be easily broken 1500 years ago and people could cast firebolts from their fingertips at will through the fragrant haze...
2. It purifies mind and body.
3. It removes uncleanliness.
The second claim also relies on very vague criteria, since we don't know what purification actually entails. If we're talking about removing toxins and other potentially harmful chemicals then incense actually does the opposite - according to a study reported by New Scientist 10 years ago burning incense releases some highly carcinogenic chemicals into the air but it isn't known how much of a risk this poses to health. This also throws claim three about removing uncleanliness into question - there's a lot of ash to clear away, but I suspect they meant an amorphous concept about uncleanliness of the soul or something equally implausible.
Incidentally, the report says that levels of benzopyrene, a highly carcinogenic chemical, were 45 times higher in a badly ventilated temple which burned incense non-stop than in homes where the residents smoke tobacco. This is a startlingly poor comparison - for one thing we've got no idea whether the people in the house are chain-smoking non-stop or how the number of cigarettes being burnt compares to the number of incense sticks being burnt. Secondly, we also have no idea how many people were in this category and how well-ventilated their homes were when they smoked. These conditions were unlikely to have remained constant as they should be in a scientific study of this nature. There may well be harmful carcinogens in incense sticks, but they should be taken in moderation like everything else in life.
In other words the benefits from burning incense are likely to be pure placebo effect. But hey, at least it's less likely to get me drunk than Dr Bach's floral remedies and a damn sight cheaper too.