Air Pollution Now Linked to Greater Chance for Mouth Cancer
In the past, scientists have connected high air pollution to a variety of health issues that range from an increased risk of dementia, to asthma, and even to changes in the heart structure. Recent studies are now finding that these issues have been taken a step further: with these rising levels of air pollution today, there is new evidence that suggests our society is put at higher risk for mouth cancer.
First released on October 9th, 2018, in the Journal of Investigative, six researchers in Taiwan explain how the association between air pollution and oral cancer was first discovered. 1 Using data that had been collected in 2009, when 66 air quality monitoring stations gathered air pollution statistics, and data from the health records of 482,659 Taiwanese men above the age of 40, researchers found that there were a total of 1,617 diagnosed cases of mouth cancer among the patients in 2012–2013 — thus revealing the first association between high rates of air pollution and mouth cancer. 2
The research team then began to focus on minute particulates known as PM2.5s, which are defined as atmospheric particulate matter that are considered fine particles because of how small they are. Research suggests that they can be caused by a variety of sources, including power plants, motor vehicles, airplanes, residential wood burning, forest fires, agricultural burning, volcanic eruptions and dust storms. Some particulates are released directly into the air, while others, when they interact with gases in the atmosphere, are instead formed. Because of their size, PM2.5 particulates reside for a longer period of time in the air, increasing the chances of human and animal life inhaling them. From there the particles are able to bypass the nose and throat and infiltrate deep into the lungs, some even able to enter the circulatory system. 3 Because of the many effects of fine particles can cause on a large number of people, PM2.5 is one of the major pollutants that is carefully monitored by health authorities around the world. Some elements of PM2.5 include compounds like polycyclic aromatic hydrocarbons — well-known cancer-causing agents. 5 According to the findings of the study completed in Taiwan, the PM2.5 particulates were sorted into four groups which ranged from lowest to highest levels of exposure that men experienced based on where they lived. Accounting for a variety of factors — some being age, amount of contact, and medical history — the findings showed that men exposed to the highest levels of PM2.5s, a calculated 40.37 mg/m3 or higher, had a greater chance of suffering from mouth cancer than men who were exposed to an average annual PM2.5 levels of 26.74 mg/m3 of air. 5 But what is the cause of this correlation?
Because this was an observational study, researchers couldn’t establish concrete cause. There are holes in the research that still need to be filled in — some including the lack of data on the amount of PM 2.5 that enters the mouth or the long-term impacts that are by exposure to the pollutant. 5 This study is the first to present the association of mouth cancer to PM 2.5, and though scientists admit to additional research being required to develop tangible claims on the relationship, the findings add to the growing evidence on the various effects that PM2.5 pollutants have on human health. 4
One opinion from Professor Frank Kelly, chair in environmental health at King’s College London, states, “Air pollution has previously been linked with several types of cancer… It is therefore not surprising that this new study in Taiwan has made a possible link with mouth cancer. However, given that air pollution concentrations and smoking incidence are much lower in the UK and we don’t chew betel all suggest that the increased risk of developing mouth cancer may be unique to Taiwan”. 2 From this, many researchers agree that it would be beneficial to further explore the link between oral cancer and air pollution in other areas of the world. According to the World Health Organization, an approximated 91% of the world’s population lives in areas with poor air quality. 4 And now being the latest to connect air pollution with yet another serious health condition, there has been an encouraging push to conduct more research in other countries, similar to that which was completed in Taiwan.
Bibliography
Kao, Y.-H. C. S.-W.; Disline Manli Tantoh,Pei-Chieh Ko,Shou-Jen Lan,Yung-Po Liaw. Association between fine particulate matter and oral cancer among Taiwanese men https://jim.bmj.com/content/early/2018/08/13/jim-2016-000263.info (accessed Oct 14, 2018). 1
Davis, N. Air pollution linked to greater risk of mouth cancer, finds study https://www.theguardian.com/environment/2018/oct/09/air-pollution-linked-to-greater-risk-of-mouth-cancer-finds-study (accessed Oct 12, 2018). 2
Levitt, T. How air pollution affects your health — infographic https://www.theguardian.com/sustainable-business/2016/jul/05/how-air-pollution-affects-your-health-infographic (accessed Oct 12, 2018). 3
Gander, K. Air pollution could increase the risk of mouth cancer, study suggests https://www.newsweek.com/air-pollution-effects-mouth-cancer-risk-1157622 (accessed Oct 12, 2018). 4
BMJ. Air pollution may be linked to heightened mouth cancer risk https://www.sciencedaily.com/releases/2018/10/181009210733.htm (accessed Oct 13, 2018). 5
