Air pollution and lung cancer – what you need to know

With just shy of 14,000 Australians diagnosed each year¹, lung cancer holds the title of Australia’s most problematic cancer, causing more deaths than any other type². The month of November is dedicated to building lung cancer awareness and educating Australians about its signs and symptoms. While most people are familiar with the more common causes of lung cancer, such as smoking, research has recently revealed another culprit at play – and it’s all around us.

There’s more to lung cancer than smoking

Despite smoking being the single most important risk factor for lung cancer, a significant proportion of people with lung cancer have never smoked. So, what else can increase your risk?

Exposure to, or inhalation of, certain cancer-causing substances (carcinogens) at home, work and through your outdoor environment can also cause lung cells to grow in an uncontrolled way. Workplace carcinogens are estimated to cause over 5,000 new cancer cases in Australia each year, with farmers, miners, drivers and transport workers most at risk³.

On top of this, outdoor air pollution has earned a reputation as a cancer-causing agent. It's estimated that the average adult inhales around 10,000 litres of air during a typical day⁴, which can contain hazardous agents including nitrates, sulphates, carbon organic chemicals, metals, soil and dust particles^5,6.

Specifically, particulate matter (PM) pollution (produced by vehicle exhaust, fossil fuel fumes, biomass burning and agricultural and livestock activities⁵) poses a significant risk to human health. This is particularly true for smaller particles, known as PM2.5, which can be inhaled deeply into the lungs⁴.

Although the risk of lung cancer from air pollution is lower than smoking – accounting for 14.1% of all lung cancer deaths, compared to 63.2% for smoking⁷ – more people are exposed to unsafe levels of pollution compared to cigarette toxins. In fact, air pollution has been attributed to more than 250,000 global lung cancer deaths each year⁸.

The growing burden of climate change

It may come as a surprise, but climate change is fast becoming a risk factor for lung cancer development, with exposure to air pollution deemed the biggest cancer threat posed by climate change⁹. According to the Bureau of Meteorology, climate change has exacerbated Australian weather patterns, particularly during the October to April months, which are known for their heatwaves, bushfires, tropical cyclones, severe thunderstorms and floods¹⁰.

Due to our hot, dry climate, bushfires are not uncommon during the Australian summer. Increasingly warmer conditions and reduced rainfall come with a higher risk of wildfires, as well as larger and more enduring bushfires – an effect witnessed during the 2019–20 bushfire season, which blanketed towns and cities in hazardous smoke.

Like air pollution, bushfire smoke contains PM2.5 particles that, when inhaled, can become trapped in the lungs. It’s reported that 11 million Australians were exposed to smoke during this catastrophic 2019–20 event⁹. In Melbourne, PM2.5 levels almost doubled the hazardous amount established by the Environmental Protection Authority (EPA). Meanwhile, these levels nearly tripled in bushfire-affected regions¹¹. The ripple effect of this was a surge in emergency department admissions for respiratory complaints¹¹.

In more recent months, Australia’s fire dial has already hit red on several occasions, indicating high fire-risk days. With projections for a hot and dry end to 2023, these conditions drive up the risk of potential bushfires this coming summer, affecting more people and potentially leading to a higher risk of lung conditions, including cancer.

Knowing what symptoms to look out for and engaging in regular health checks with your general practitioner can help in the prevention and early detection of lung cancer. 

Be aware of these symptoms

Lung cancer affects the lower respiratory system, causing tumours to grow on the trachea (windpipe), bronchi (the passageways into the lungs) and the lung itself¹⁰. Because of where these growths are situated, most lung cancer symptoms are respiratory in nature, including coughing, shortness of breath, hoarseness, chest pain or persistent pneumonia¹².

If you experience any of these symptoms, book an appointment with your general practitioner for a health review. And routine checks can detect early signs of a health issue, so pencil in a yearly check-up with your doctor. 

Engage in lung cancer screening

The Federal Government is working towards improving lung cancer outcomes through a new National Lung Cancer Screening Program. It is anticipated that this program will prevent more than 500 lung cancer deaths each year by targeting high-risk individuals, improving training and education, and enhancing screening infrastructure¹³. Although still in its early stages, this program represents a positive step in reducing lung cancer deaths. Watch this space for more information! 

Working together to protect health with Zurich Evolve

Zurich Evolve is our commitment to health, partnering with you to stay healthy and feel healthier, even when faced with the challenges of cancer. Healthcare makes up 7% of Australian carbon emissions¹⁴ and focusing on prevention, we can help keep people healthy and reduce their requirements for resource-intense tertiary healthcare. Zurich Evolve is about making life better for everyone, because healthy people and healthy communities will have a positive impact on our planet.

References

1.     Cancer Council, ‘Lung cancer is Australia’s biggest cancer killer’, November 2021.

2.     Australian Institute of Health and Welfare, ‘Deaths in Australia’, July 2023.

3.     Cancer Council, ‘Workplace cancer’.

4.     Christiani DC, ‘Ambient air pollution and lung cancer: Nature and nurture’, Am J Respir Crit Care Med, 204(7):752-753, 2021, doi: 10.1164/rccm.202107-1576ED.

5.     Clofent D, Culebras M, Loor K, Cruz MJ, ‘Environmental pollution and lung cancer: The carcinogenic power of the air we breathe’, Arch Bronchoneumol, 57(5):317-318, 2021, doi: 10.1016/j.arbr.2021.03.002.

6.     American Lung Association, ‘The connection between lung cancer and outdoor air pollution’, June 2016.

7.     Turner MC, Anderson ZJ, Baccarelli A, Diver WR, Gapstur SM, Pope CA, Prada D, Samet J, Thurston G, Cohen A, ‘Outdoor air pollution and cancer: An overview of the current evidence and public health recommendations’, CA Cancer J Clin, 2020, doi: 10.3322/caac.21632.

8.     European Society for Medical Oncology, ‘Scientists discover how air pollution may trigger lung cancer in never-smoker’, September 2022.

9.     Agbafe V, Berlin NL, Butler CE, Hawk E, Offodile AC, ‘Prescriptions for mitigating climate change-related externalities in cancer care: A surgeon’s perspective’, Journal of Clinical Oncology, 40(18)1976-1979, 2022, doi: 10.1200/JCO.21.02581.

10.  Bureau of Meteorology, ‘Australia’s peak season for severe weather and risk of tropical cyclones’, October 2023.

11.  Grattan Institute: https://grattan.edu.au/wp-content/uploads/2020/05/Grattan-Institute-submission-Victorian-Inquiry.pdf

12.  Elsevier Clinical Key, ‘Lung cancer (non-small cell)’, May 2023, subscription required to view.

13.  Australian Government Department of Health and Aged Care, ‘National lung cancer screening’, June 2023

14.  https://www.mja.com.au/journal/2022/216/2/high-value-health-care-low-carbon-health-care