The link between air pollution and cancer

According to a 2012 estimation from the World Health Organization (WHO), approximately 7 million people worldwide die prematurely due to air pollution. This is one in eight of total global deaths and is double that of their previous estimates. The WHO declares that air pollution is ‘now the world’s largest single environmental risk’ and has classified air pollution as a class I human carcinogen1. Cancer is a leading cause of death amongst those suffering from air pollution-caused illness. How does air pollution cause cancer? Which types of cancer? How can you protect yourself? Read more below.

A pink cancer ribbon

The dangers of particulate matter or ‘PM’

Humans take thousands of breaths, inhaling approximately 10,000 litres of air each day. These breaths bring a myriad of air pollutants into our lungs. The most dangerous type of air pollution on human health is particulate matter, also known as fine particle pollution or ‘PM’. This type of air pollution, due to its small size, enters the body through the respiratory system (inhalation) where it then gains access to other organs of the body like the heart, brain, and bloodstream.

The three types of PM and their sources are as follows:

  • PM10 – particles between 2.5 and 10 microns
    • The largest form of PM
    • Sources include road traffic, industry, domestic fuel burning, mould spores, dust, some bacteria, some types of smoke, and some airborne viral particles2
  • PM2.5 – particles between 0.1 and 2.5 microns
    • The type of PM most associated with adverse health effects
    • Sources include the burning of fuels (mainly fossil fuels like petrol, diesel, natural gas, and oil but also wood) and wildfires
  • PM0.1 – particles smaller than 0.1 microns
    • The least-researched type of PM
    • A German study found that this type of PM has the potential to be more harmful than PM2.5 and makes up about 83% of indoor air pollutants3
PM size comparisons

Source 4

Air pollution and cancer

Studies have shown an increase in cancer rates as a result of breathing in polluted air. A report published by the European Environment Agency (EEA) in February 2023 states that more than 10% of all cancer cases in Europe are due to air pollution5.

Lung cancer

Most of the above cancer deaths are attributed to lung cancer, representing 9% of deaths according to the 2023 EEA report. This is not the first time that lung cancer caused by air pollution has made headlines: in 2004, the WHO estimated that 62,000 lung cancer deaths worldwide were attributed to ambient air pollution. Furthermore, more than 1.3 million new cases of lung cancer have been reported per year on a global scale6.

Head, neck, and nasopharyngeal cancers

In addition to lung cancer, air pollution has also been linked to cancers of the head and neck as well as nasopharyngeal carcinoma. Studies performed in the United States, India, and China have discovered a connection of rising cases of oral, laryngeal, and pharyngeal cancers due to air pollution exposure7. One study noted a more specific relationship between ozone and lung and larynx cancers8.

Industrialisation and urbanisation are two main factors associated with rising cancer rates of these types. The burning of solid fuels like coal, charcoal, and wood significantly increases the risk of cancer in places like India where people are heavily dependent upon these types of fuel for heating and cooking7.

Similar increases in the rate of head and neck cancer were found in a study performed in Southern Brazil. In this region of the world, rates of upper aero-digestive tract cancers are some of the highest in the world. The study estimates that 30% of these cancers are linked to the use of wood stoves9.

Breast and bladder cancers

Air pollution is also linked to higher incidence of breast and bladder cancers.

A 2010 Canadian study found that postmenopausal women who are more heavily exposed to ambient air pollution, NO2 specifically, experience a significantly elevated risk of breast cancer. Exposure to ambient air pollution can lead to an increased risk of 25% for every increase of 5 ppb of pollutant concentration10.

A 2007 study performed in Spain found that not only is air pollution confirmed to increase the risk of lung cancer, it increases the risk of bladder cancer as well. The study focused on individuals living in cities of more than 100,000 inhabitants. It was observed that in these locations, the risk for bladder cancer is increased overall, likely caused by exposure to polycyclic aromatic hydrocarbons (released by the combustion of organic materials such as tobacco, wood, and other fuels) and diesel emissions from road traffic and industry11.

Air pollution at an industrial site

Which pollutants are the most dangerous?

Certain pollutants are high on the priority list for worldwide monitoring due to the risk they pose to human health. The pollutants that have been tested to cause the most adverse health effects are:

  • Sulphur dioxide (SO2)
  • Nitrogen dioxide (NO2)
  • Ozone
  • Carbon dioxide
  • Particulate matter (PM) indicators
    • Black smoke
    • Total suspended particles (TSP)
    • PM10, PM2.5, and PM0.1

What steps can we take to protect ourselves?

Due to the mounting rates of the above cancers in non-smokers, the need to find solutions to combat their incidence is dire.

There are things that each and every one of us can do to reduce our contributions to air pollution. We should all try to use natural products wherever possible. We can help to limit our contributions to indoor air pollution by purchasing and using low-VOC or VOC-free products (such as paints or cleaning products) and to steer clear of chemical pesticide use indoors and outdoors. We should also make efforts wherever possible to reduce our usage of individual vehicle transportation that release harmful fossil fuel emissions. Public transport, biking, or walking are all eco-friendly, zero- or lower-emission options for shorter journeys. On a nationwide scale, we should also be asking our governmental leaders to support clean energy bills and further regulate the amounts of pollutants being released into our breathing air. Breathing clean air is a right to which we are all entitled.

Solar panels under a blue sky

It is important to keep in mind that indoor spaces are usually 2 to 5 times more polluted than outdoor spaces. In some places, indoor pollution levels can reach up to 100 times more concentrated than outdoor levels! To protect yourself at home and in the workplace from indoor pollution, an excellent solution is to equip your indoor spaces with an air purifier.

Breathe fresh air with Eoleaf

Eoleaf air purifiers are equipped to filter all types of air pollutants from your indoor space. This includes:

Our devices contain 8 different air purification technologies in an all-in-one, easy-to-change filter. This proprietary technology is one of the most advanced available on today’s market and ensures thorough filtration of 99.97% of any airborne pollutant down to a size of 0.01 microns. Do not hesitate to reach out to our team of air purification experts or to refer to our Buying Guide for assistance in choosing the right device for you.

Eoleaf's AEROPRO 40 air purifier


References

1 World Health Organization. (2014, March 25). 7 million premature deaths annually linked to air pollution. World Health Organization. https://www.who.int/news/item/25-03-2014-7-million-premature-deaths-annually-linked-to-air-pollution

2 Urban Air Quality. European Environment Agency. (2022, June 16). Retrieved April 25, 2023, from https://www.eea.europa.eu/themes/air/urban-air-quality

3 Zhao, J., Birmili, W., Wehner, B., Daniels, A., Weinhold, K., Wang, L., Merkel, M., Kecorius, S., Tuch, T., Franck, U., Hussein, T., & Wiedensohler, A. (2020). Particle mass concentrations and number size distributions in 40 homes in Germany: Indoor-to-outdoor relationships, diurnal and seasonal variation. Aerosol and Air Quality Research, 20(3). https://aaqr.org/articles/aaqr-19-09-oa-0444

4 Environmental Protection Agency. (2023, July 11). EPA. https://www.epa.gov/pm-pollution/particulate-matter-pm-basics

5 Exposure to pollution causes 10% of all cancer cases in Europe. European Environment Agency. (2023, February 7). https://www.eea.europa.eu/highlights/pollution-and-cancer

6 Straif, K., Cohen, A., & Samet, J. (2013b). World Health Organization International Agency for Research on Cancer. WHO IARC. https://www.iarc.who.int/wp-content/uploads/2018/07/AirPollutionandCancer161.pdf

7 Wong IC, Ng YK, Lui VW. Cancers of the lung, head and neck on the rise: perspectives on the genotoxicity of air pollution. Chin J Cancer. 2014 Oct;33(10):476-80. doi: 10.5732/cjc.014.10093. Epub 2014 Jul 11. PMID: 25011457; PMCID: PMC4198750.

8 Pereira FA, de Assunção JV, Saldiva PH, Pereira LA, Mirra AP, Braga AL. Influence of air pollution on the incidence of respiratory tract neoplasm. J Air Waste Manag Assoc. 2005 Jan;55(1):83-7. doi: 10.1080/10473289.2005.10464603. PMID: 15704542.

9 Wong IC, Ng YK, Lui VW. Cancers of the lung, head and neck on the rise: perspectives on the genotoxicity of air pollution. Chin J Cancer. 2014 Oct;33(10):476-80. doi: 10.5732/cjc.014.10093. Epub 2014 Jul 11. PMID: 25011457; PMCID: PMC4198750.

10 Crouse DL, Goldberg MS, Ross NA, Chen H, Labrèche F. Postmenopausal breast cancer is associated with exposure to traffic-related air pollution in Montreal, Canada: a case-control study. Environ Health Perspect. 2010 Nov;118(11):1578-83. doi: 10.1289/ehp.1002221. PMID: 20923746; PMCID: PMC2974696.

11 Castaño-Vinyals G, Cantor KP, Malats N, Tardon A, Garcia-Closas R, Serra C, Carrato A, Rothman N, Vermeulen R, Silverman D, Dosemeci M, Kogevinas M. Air pollution and risk of urinary bladder cancer in a case-control study in Spain. Occup Environ Med. 2008 Jan;65(1):56-60. doi: 10.1136/oem.2007.034348. Epub 2007 Jul 18. PMID: 17634245.

Eoleaf's range of air purifiers

1 of 5