Burning incense ceremonially has long been a tradition in many religious practices, including that of the Zhongyuan Ghost Festival, held annually by the people of Taiwan. During this festival, the Taiwanese customarily prepare feasts and burn incense as offerings for the appeasement of ghosts. This year, however, the Environmental Protection Agency has warned again that burning such incense outdoors is illegal and will result in large fines due to the damaging effects of incense smoke on the atmosphere.



With the EPA imposing such a ban, it is clear that just as burning incense outdoors poses a threat to the environment, burning incense indoors is extremely hazardous to human health. While often marketed as a method for promoting a sense of peace and purifying the air, incense simply masks odors by emitting large quantities of particulate matter. And because these particulates have a mere diameter of no more than two and a half microns (a micron equals one millionth of a meter), they are easily able to avoid filtration and make their way deep into the lungs.

Upon absorption into the respiratory system, particulate matter may cause a variety of adverse health effects, such as headaches, lethargy, dizziness, nausea, and eye, nose, and throat irritation. These symptoms, when triggered by pollutants such as incense smoke, will become less severe and often disappear when the source of pollution is removed. However, with continued exposure, studies have shown that inhaling the smoke of incense can lead to serious illnesses, including asthma, dermatitis, and cancers.

Because of such serious risks, the practice of burning incense has recently received increasing attention. But while researchers and regulatory groups warn against the dangers, they also know that many will continue burning incense, whether for traditional practices or for personal enjoyment. Therefore, although discontinuing the use of incense is most strongly suggested, researchers offer additional suggestions for preventing the inhalation of smoke particulates, including ventilating rooms to outdoor air and utilizing negative ion generators.

Negative ion generators, such as room ionizers, have provided the benefits of negative ions for decades with their ability to remove hazardous particulates from the air, including pollen, dust, chemicals, mold spores, animal dander, bacteria, and smoke. Once negative ions are released into the air, they quickly attract such particulates, which are positively charged. As the negative ions and positive particulates cluster together, they become heavy, ultimately falling to surfaces where they can be vacuumed or dusted away rather than inhaled.

In nature, the benefits of negative ions are most noticeable after thunderstorms, at beaches, or around waterfalls where neutral water molecules can easily lose electrons upon impact. Once an electron has escaped, it then attaches itself to another nearby particle. If the resulting atom or molecule contains more electrons than protons, a negative charge is formed and, thus, a negative ion. These ions are, in fact, one of the earth's natural cleansers, and ionizers simply utilize this knowledge to create the same purifying effects indoors.

Although many types of air cleaners exist, one of the benefits of negative ions lies in their ability to remove finer particulates (including those of incense smoke) from the air than other types of purifiers. For example, while a HEPA filter can only eliminate particles down to three tenths of a micron in size, a negative ion generator is able to purify the air of particulates as small as one tenth of a micron. Further, while fan-based cleaners are only able to purify air drawn through their filters, ionizers disperse negative ions throughout a room, removing fine particles even several feet away from the machine.

Because indoor air quality has become a rising concern, with indoor air anywhere from two to ten times more polluted than that outdoors, the use of a negative ion generator has become increasingly important. And while not a cure-all, the benefits of negative ions can help to remedy the risks of burning incense. With their ability to freshen and purify the air, to promote a sense of calm and well-being, and to provide health benefits such as an enhanced immune system and stabilized blood pressure, negative ions, as produced by ionizers, can work wonders.