Editing Incense (section)

==Health risks from incense smoke==
Incense smoke contains various contaminants including gaseous pollutants, such as [[carbon monoxide]] (CO), [[nitrogen oxide]]s ({{Chem|NO|x}}), [[sulfur oxide]]s ({{Chem|SO|x}}), [[volatile organic compounds]] (VOCs), and adsorbed toxic pollutants ([[polycyclic aromatic hydrocarbons]] and [[toxic metal]]s). The solid particles range between around {{convert|10| and(-)|500|nm|sigfig=1|abbr=off}}. In a comparison, Indian sandalwood was found to have the highest emission rate, followed by Japanese [[agarwood|aloeswood]], then Taiwanese [[aloeswood]], while Chinese smokeless sandalwood had the least.<ref name="siao">{{cite journal |author=Siao Wei See |title=Physical characteristics of nanoparticles emitted from incense smoke |journal=Science and Technology of Advanced Materials |volume=8 |issue=1–2 |year=2007 |pages=25–32 |doi=10.1016/j.stam.2006.11.016 |author2=Rajasekhar Balasubramanian |author3=Umid Man Joshi |bibcode=2007STAdM...8...25S|doi-access=free}}</ref>

Research carried out in [[Taiwan]] in 2001 linked the burning of incense sticks to the slow accumulation of potential [[carcinogen]]s in a poorly ventilated environment by measuring the levels of [[polycyclic aromatic hydrocarbon]]s (including [[benzopyrene]]) within Buddhist temples. The study found gaseous [[aliphatic compound|aliphatic]] [[aldehyde]]s, which are carcinogenic and mutagenic, in incense smoke.<ref>{{Cite journal |volume=53 |issue=3 |pages=374–381 |vauthors=Lin JM, Wang LH |title=Gaseous aliphatic aldehydes in Chinese incense smoke |journal=Bulletin of Environmental Contamination and Toxicology |date=September 1994 |pmid=7919714 |doi=10.1007/bf00197229 |s2cid=33588092 |url=http://ntur.lib.ntu.edu.tw/bitstream/246246/160931/1/11.pdf |access-date=2022-03-03 |archive-date=2023-03-24 |archive-url=https://web.archive.org/web/20230324014433/http://ntur.lib.ntu.edu.tw/bitstream/246246/160931/1/11.pdf |url-status=dead }}</ref> A survey of risk factors for lung cancer, also conducted in Taiwan, noted an inverse [[association (statistics)|association]] between incense burning and [[adenocarcinoma]] of the lung, though the finding was not deemed [[statistical significance|significant]].<ref>{{cite journal |vauthors=Ger LP, Hsu WL, Chen KT, Chen CJ |title=Risk factors of lung cancer by histological category in Taiwan |journal=Anticancer Res. |volume=13 |issue=5A |pages=1491–500 |year=1993 |pmid=8239527}}</ref>

In contrast, epidemiologists at the Hong Kong Anti-Cancer Society, Aichi Cancer Center in Nagoya, and several other centers found: "No association was found between exposure to incense burning and respiratory symptoms like chronic cough, chronic sputum, chronic bronchitis, runny nose, wheezing, asthma, allergic rhinitis, or pneumonia among the three populations studied: i.e. primary school children, their non-smoking mothers, or a group of older non-smoking female controls. Incense burning did not affect lung cancer risk among non-smokers, but it significantly reduced risk among smokers, even after adjusting for lifetime smoking amount." However, the researchers qualified their findings by noting that incense burning in the studied population was associated with certain low-cancer-risk dietary habits, and concluded that "diet can be a significant confounder of epidemiological studies on air pollution and respiratory health."<ref>{{cite journal |author1=Koo, Linda C. |author2=Ho, J.H-C. |author3=Tominaga, Suketami |author4=Matsushita, Hidetsuru |author5=Matsuki, Hideaki |author6=Shimizu, Hiroyuki |author7=Mori, Toru |date=1995-11-01 |title=Is Chinese Incense Smoke Hazardous to Respiratory Health?: Epidemiological Results from Hong Kong |journal=Indoor and Built Environment |volume=4 |issue=6 |pages=334–343 |doi=10.1177/1420326X9500400604 |s2cid=73146243}}</ref>

Although several studies have not shown a link between incense and [[lung cancer]], other types of cancer have been directly linked to burning incense. A study published in 2008 in the medical journal ''[[Cancer (journal)|Cancer]]'' found that incense use is associated with a statistically significant higher risk of cancers of the [[upper respiratory tract]], with the exception of [[nasopharyngeal cancer]]. Those who used incense heavily also were 80% more likely to develop [[squamous-cell carcinoma]]s. The link between incense use and increased cancer risk held when the researchers weighed other factors, including cigarette smoking, diet and drinking habits. The research team noted that "This association is consistent with a large number of studies identifying carcinogens in incense smoke, and given the widespread and sometimes involuntary exposure to smoke from burning incense, these findings carry significant public health implications."<ref>{{cite news |url=https://www.reuters.com/article/us-incense-cancers-idUSPAT56944620080825 |title=Burning incense linked to respiratory cancers |work=Reuters |date=2008-08-25 |access-date=2016-07-20}}</ref>

In 2015, the South China University of Technology found toxicity of incense to Chinese hamsters' ovarian cells to be even higher than cigarettes.<ref>{{cite journal |doi=10.1007/s10311-015-0521-7 |volume=13 |issue=4 |title=Higher cytotoxicity and genotoxicity of burning incense than cigarette |journal=Environmental Chemistry Letters |pages=465–471 |year=2015 |last1=Zhou |first1=R. |last2=An |first2=Q. |last3=Pan |first3=X. W. |last4=Yang |first4=B. |last5=Hu |first5=J. |last6=Wang |first6=Y. H. |s2cid=93495393}}</ref> Incensole acetate, a component of [[frankincense]], has been shown to have anxiolytic-like and antidepressive-like effects in mice, mediated by activation of poorly-understood [[TRPV3]] ion channels in the brain.<ref>{{cite journal |vauthors=Moussaieff A, Rimmerman N, Bregman T|display-authors=etal |title=Incensole acetate, an incense component, elicits psychoactivity by activating TRPV3 channels in the brain |journal=FASEB J. |volume=22 |issue=8 |pages=3024–34 |date=August 2008 |pmid=18492727 |pmc=2493463 |doi=10.1096/fj.07-101865|doi-access=free }}</ref>