Lung cancer and air pollution

Lung cancer is the leading cause of death in the developed world. In the UK alone, between the years of 2016-2018, there were 48,549 new cases of lung cancer reported, and from 2017-2019, lung cancer claimed the lives of 34,771 people. According to Cancer Research UK, 79% of those deaths are preventable¹. While smoking remains the number one cause of lung cancer, cases of lung cancer in non-smokers are on the rise with air pollution to blame: air pollution (outdoor and indoor) is responsible for 1 in 10 cases of lung cancer².

To address this very phenomenon, a September 2022 study by the Francis Crick Institute in London was triggered after an influx of never-smokers began developing lung cancer. The findings have provided some breakthrough information about the occurrence of lung cancer in healthy individuals, allowing scientists to understand more about the link between lung cancer and air pollution. What is air pollution and how does it cause lung cancer? Can an air purifier protect you from the dangers of air pollution? Find out below.

What is air pollution?

The World Health Organisation (WHO) defines air pollution as an event where substances that can be detrimental to our and/or the planet’s health are released into the air that we breathe. It is made up of tiny solid and liquid airborne particles that may have various chemical, physical, or biological sources. One thing remains consistent: these substances have a capacity to change the natural characteristics of the atmosphere. Some common sources of air pollution are emissions from motor vehicles, industrial facilities, natural events like forest and bush fires, and household combustion devices like those that use wood and natural gas³.

The combustion of fossil fuels is a large contributor to both air pollution and climate change, meaning that finding solutions to combat air pollution would directly support initiatives to fight climate change.
According to the WHO, 99% of the world’s population breathes air that exceeds WHO guideline limits, meaning that nearly all of us are breathing poor quality air. Communities of low- and medium-income are disproportionately impacted³.

Two breakthrough studies on lung cancer in non-smokers

Air pollution-caused lung cancer caused 300,000 deaths in the year 2019 on a global scale. In the UK, 60,000 individuals who have never smoked died due to air pollution-related lung cancer⁶. 

There are several explanations that explain how indoor and outdoor air pollution cause cancer. One such explanation states that these tiny particles of air pollution enter the body through inhalation, build up in the lungs, and alter the way that cells replicate. This ultimately causes DNA changes and mutations in the cells which lead to cancer².

A long-term study by the American Cancer Society began in 1982 and collected data up through 31 December 1998. Over 1.2 million adults were enrolled in the study and were required to complete a questionnaire providing their individual risk factor data (age, sex, race, smoking history, education, and diet, to name a few). The study then linked this risk factor data with air pollution data for metropolitan areas in the United States, then combined enrolees’ vital status and cause of death data at the end of the study. Findings showed that each 10 μg/m(3) increase in fine particulate matter like PM2.5 led to a 4% increase in all-cause (due to any cause) mortality; a 6% increase in cardiopulmonary mortality; and an 8% increase in lung cancer mortality⁴. This study was one of the first of its kind to draw a link between fine particle pollution and cardiopulmonary and lung cancer mortality, potentially due to cell mutations.

In more recent years, the September 2022 study mentioned at the beginning of this article focused on the diagnosis of non-smokers with lung cancer. The scientists at the Francis Crick Institute focused on PM2.5, a type of air pollution that is smaller than a human hair. The study presented the following findings:

• Places experiencing higher levels of air pollution had more cases of cancer not related to smoking
• When PM2.5 is present in the lungs, it causes the release of interleukin-1-beta
• Once the alarm is sounded, inflammation is caused and cells in the lungs are activated in order to repair damage
• Acquired with age, one cell in every 600,000 cells in the lungs of a 50-year-old already contains potentially cancerous mutations; these cells usually only become cancerous as a result of interaction with interleukin-1-beta⁵

This gives some clarity into how people who had never smoked were developing lung cancer. Mutations in cells exposed to chemical signals triggered by air pollution are increasing lung cancer rates. Researchers are working on a solution using a drug that blocks this chemical alarm signal, and early trial results are promising: researchers have been able to stop the development of cancer in mice who were exposed to particulate matter⁵.

This is good news! However, the best way to avoid unnecessary cell mutations is to reduce the problem at the source: we need to address the dangers of air pollution⁵.

Who is most at risk?

Air pollution has the greatest impact on infants and children, the elderly, pregnant women, and those who are immunocompromised (especially those with pre-existing respiratory, lung, or heart disease). Also heavily affected are those who live or exercise near areas with high outdoor pollution like motorways or industrial sites.

In 2013, an 8-year-old girl from Jiangsu province in China was one of the youngest people on record to be diagnosed with lung cancer due to air pollution. Living near a busy road exposed her to high levels of PM2.5 A People’s Daily report about the girl and her illness states that lung cancer is becoming more and more prominent in China due to poor air quality⁷.

How can we protect ourselves from air pollution-linked lung cancer?

Reducing air pollution is one of the world’s most pressing public health issues. Not only does it claim the lives of many individuals around the world each year, but it has a massive economic impact: global health costs of air pollution-caused illness were estimated to be around $8.1 trillion in 2019⁸.

There are steps we can all take to reduce our contribution to air pollution, outdoor and indoor alike. The following list can guide us in our efforts:

1. Try walking or cycling to work rather than driving your vehicle, and use public transport instead whenever possible for other journeys
• Limit outdoor physical activity if outdoor pollution levels are high and always avoid exercising next to highly polluted areas like motorways or industrial facilities
• Track your local air quality using a local air quality index forecast to determine whether or not air quality levels are safe to perform outdoor activities
2. Shut off the engine of your car whilst waiting in traffic or parked; never leave your car idling especially if driving a diesel engine
3. Avoid smoking in general, but particularly avoid doing so indoors
4. Properly aerate your home by opening windows and doors
5. Search out products that are eco-friendly or natural: avoid purchasing products that contain dangerous, polluting VOCs (volatile organic compounds) which can be found in products like paints, lacquers, and adhesives
6. Reduce the use of wood and coal in heating your home
7. Do not burn garden or any other type of waste
8. Plant trees – they absorb carbon dioxide and help filter air pollutants

As diligent as we may be in following the steps above, air quality is sometimes out of our control at the individual scale. An excellent and foolproof way to protect yourself from the dangers of air pollution is to invest in an air purifier in your home or workplace.

Here at Eoleaf, our high-quality air purifiers protect you and your lungs from a variety of air pollutants. All of our devices are equipped with HEPA-certified filters. Any filter receiving the HEPA designation is capable of filtering 99.97% of particles of a size greater than or equal to a diameter of 0.01 µm in a single pass. They can filter out all fine particulate matter and pollutants like PM2.5 and PM0.1, germs (bacteria and viruses), moulds and spores, and allergens (pollen, dust, and dust mites).

If you need some guidance in choosing the device that is right for you and your space, don’t hesitate to get in touch! Our goal is to help protect you and your loved ones from the dangers of air pollution. Start breathing cleaner air today.

References

¹ Lung cancer statistics. Cancer Research UK. (2022, May 31). Retrieved January 10, 2023, from https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/lung-cancer 

² How can air pollution cause cancer? Cancer Research UK. (2021, August 17). Retrieved January 10, 2023, from https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/air-pollution-radon-gas-and-cancer/how-can-air-pollution-cause-cancer

³ World Health Organization. (2023). Air Pollution. World Health Organization. Retrieved January 10, 2023, from https://www.who.int/health-topics/air-pollution#tab=tab_1 

⁴ Pope III, C. A., Burnett, R. T., Thun, M. J., Calle, E. E., Krewski, D., Ito, K., & Thurston, G. D. (2002). Lung cancer, cardiopulmonary mortality, and long-term exposure to Fine Particulate Air Pollution. JAMA, 287(9), 1132–1141. https://doi.org/10.1001/jama.287.9.1132 

⁵ Gallagher, J. (2022, September 10). Cancer rules rewritten by air-pollution discovery. BBC News. Retrieved January 10, 2023, from https://www.bbc.com/news/health-62797777 

⁶ Scientists reveal how air pollution can cause lung cancer in people who have never smoked. The Francis Crick Institute. (2022, September 10). https://www.crick.ac.uk/news/2022-09-10_scientists-reveal-how-air-pollution-can-cause-lung-cancer-in-people-who-have-never-smoked 

⁷ Duggan, J. (2013, November 7). China’s air pollution blamed for 8-year-old’s lung-cancer. The Guardian. https://www.theguardian.com/environment/chinas-choice/2013/nov/07/china-air-pollution-eight-year-old-cancer 

⁸ Mwaura, A., & Mudu, P. (2022, September 7). WHO releases new repository of resources for air quality management. World Health Organization. https://www.who.int/news/item/07-09-2022-who-releases-new-repository-of-resources-for-air-quality-management