In 1965, the U.S. Surgeon General—prompted in part by the work of then–University of Michigan health policy researcher Ken Warner—published a landmark report confirming that cigarette smoking was the principal cause of lung cancer in the United States.¹ Since that time, tobacco use has declined significantly, thanks in large part to public health efforts such as anti-smoking media campaigns and school-based education programs.¹ However, lung cancer continues to be one of the most prevalent cancers among both men and women in the U.S.² In 2025, breast cancer is projected to have the highest incidence (319,750 new cases), followed by lung cancer (238,340 new cases) and prostate cancer (191,930 new cases).³ Despite its lower incidence, lung cancer remains the leading cause of cancer-related death for both men and women, accounting for about one in five cancer deaths nationwide.³ In Michigan, lung cancer ranks 36th among all states for new cases and 20th for survival rates.⁴ Importantly, individuals who have never used tobacco can also develop lung cancer due to environmental exposures or other, sometimes unknown, factors. According to the U.S. Environmental Protection Agency (EPA), radon is the second leading cause of lung cancer in the country.⁵

Research over the past 50 years has consistently confirmed that tobacco remains the most common carcinogen associated with lung cancer. However, exposure to elevated levels of radon gas in homes or workplaces has also been shown to increase the incidence and mortality of lung cancer significantly. According to the United States Environmental Protection Agency (EPA), radon is a naturally occurring radioactive gas produced by the breakdown of rocks, soil, and groundwater.^5-6 It has been detected in all U.S. states and can affect any home, not only those with basements. Because radon is colorless and odorless, it can only be identified through specific testing. The risk of lung cancer is especially elevated among smokers who are also exposed to radon, compared with nonsmokers. Notably, among individuals who have never smoked, approximately 26% of lung cancer deaths have been linked to radon exposure.⁷

Other exposures also increase the risk of lung cancer, including asbestos, arsenic, chromium, nickel, beryllium, cadmium, tar, soot, and diesel exhaust.⁸ These substances can cause lung cancer in individuals who have never smoked but have been exposed to them in the workplace. In addition to occupational exposures, high levels of air pollution contribute to an increased risk of lung cancer as well as other cancers. Carcinogenic air pollution is most commonly detected in urban, densely populated areas, particularly in industrial districts, which are often home to low-income and minority populations.^8-13

There have been tremendous advancements in lung cancer treatment over the past 15 years, with some of the most significant developments involving targeted therapies that inhibit cancer cell growth and reproduction.^14-15 While these therapies can be highly effective initially, their benefits are often temporary, as cancer cells may eventually develop resistance and overcome these therapeutic barriers, leading to reduced drug efficacy. Additionally, targeted therapies are costly, creating economic disparities in access to treatment. Individuals with low incomes or those dependent on Medicaid are less likely to receive these advanced therapies in the U.S.¹⁵

Early diagnosis and intervention significantly improve outcomes and decrease mortality. Early detection has been shown to extend life expectancy after diagnosis by up to five years or more.¹⁶ Inherent aspects of clinical medicine contribute to health inequities, particularly among individuals in lower socioeconomic classes, who consequently have a lower probability of receiving timely detection and diagnosis. Inconsistent access to primary care across economic strata may become an even greater concern with anticipated reductions in federal Medicaid resources. Early detection is critical, as delays in diagnosis increase the risk of metastasis and lead to worse outcomes for patients. Low-dose computed tomography (LDCT) screening, when applied appropriately in high-risk populations, has been demonstrated to reduce lung cancer mortality and may help address some of these disparities.¹⁷

Public health leadership should continue emphasizing primary prevention of smoking, given the well-established, 60-year relationship between tobacco use and lung cancer.¹⁸ However, it is time to sound the alarm on the second leading cause of lung cancer—radon exposure.^2,19 While smoking prevention efforts have successfully reduced tobacco use and increased public awareness of its dangers, similar attention must now be directed toward environmental risks such as radon.¹⁹

In most communities, radon testing is recommended during home sales. Although not always mandatory, buyers often request testing, and if elevated levels are detected, mitigation typically becomes part of the negotiation process before closing.⁶  Despite past public health campaigns, awareness of radon exposure remains low, and many homeowners only learn of the risk when selling their property.^7,19-23 Homes that are not on the market are rarely tested, particularly in older or rural communities where housing turnover is limited. To protect public health, we recommend implementing comprehensive domestic radon detection programs and making radon testing as routine as the installation of smoke detectors in homes certified for occupancy.

Although few employers routinely screen for radon, workplace testing can be conducted at a modest cost.^24-25 In the absence of a federal mandate—since regulations are often determined by state and local laws—routine radon screening in workplaces has been slow to develop. Now is the time to expand monitoring and mitigation efforts to reduce occupational exposure to radon.

Early diagnosis and intervention (secondary prevention) can significantly improve outcomes, increase five-year survival rates, and decrease mortality.^26-27 However, inconsistent and class-based disparities in clinical access contribute to health inequities, resulting in a lower probability of early detection and diagnosis for many individuals. Inconsistent access to primary care across economic strata may become an even greater challenge in the near future, with anticipated reductions in federal Medicaid resources. Yet, it is not simply inequitable access that delays detection and diagnosis—primary care physicians are often constrained by standardized recommendations that discourage consideration of atypical presentations beyond established screening criteria.

Approximately 10–20% of diagnosed lung cancer cases occur in individuals with no identifiable risk factors.²⁷ This reality raises two critical questions:

1. How can we devise effective primary prevention strategies when the etiologies beyond tobacco and radon exposure remain poorly understood, mainly based on research conclusions drawn more than six decades ago?
2. Why do individuals with no known exposure to tobacco, radon, or other carcinogens develop lung cancer?

Except for limited exploratory work examining genetic and hereditary influences, the current research agenda remains strikingly deficient in investigating these unexplained etiologies.

Secondary prevention efforts also remain narrowly confined to “best practice” recommendations for screening.²⁸ However, patients who do not present with recognized risk factors often experience diagnostic delays in primary care settings. When detection is delayed, these patients are far more likely to receive an initial diagnosis at Stage IV—often accompanied by the agonizing clinical counsel to “hope for the best, but prepare for the worst.”

The Michigan Department of Health and Human Services and the University of Michigan have summarized the current recommendations for routine lung cancer screening.^29-30 These guidelines have changed little over the past 35 years and continue to exclude screening when there is “no evidence of disease.” Notably, a persistent unexplained cough—an early but nonspecific symptom—is not identified within these standardized recommendations. We recommend that this presentation should qualify as a potential indicator of disease and trigger diagnostic suspicion, including CT screening, especially among individuals over age 55 who may represent the etiologically unexplained subset of newly diagnosed lung cancer cases.⁸

As Smolle and Pichler²⁷  emphasize:

“From the epidemiological perspective, other risk factors such as metabolic disorders may play a role, as well as germline mutations that lead to cancer formation in certain individuals independent from lifestyle and exposure to carcinogens. The take-home message is the paramount importance of personalized medicine, in-depth molecular assessment, and targeted treatment options—especially in never-smoking patients suffering from lung cancer.”
 

Policy must also address—through rigorous research and, ultimately, stronger protections—the needs of populations that face disproportionate environmental risks or have historically borne the burden of environmental injustice. In Michigan, this requires prioritizing remediation efforts in communities such as Detroit, Kalamazoo, Flint, Saginaw, Lansing, and Grand Rapids.³¹ Early diagnosis is a critical component of improving outcomes. A recent study from Henry Ford Health found that non-smokers—like my wife—and particularly those residing near textile and industrial plants, are significantly more likely to be diagnosed at advanced stages of lung cancer compared to individuals living farther from these sites.³² The Michigan Department of Health and Human Services’ cancer dashboard, which tracks early lung cancer detection statewide, is an essential tool and merits robust support.³³ In addition, new research in Michigan is advancing precision medicine approaches, including the development of microfluidic chips capable of detecting lung cancer at early stages, distinguishing mutational subtypes, and informing targeted treatment strategies.³⁴

References

1. Surgeon General of the United States. (1965). Smoking and Health: Report of the Advisory Committee to the Surgeon General of the Public Health Service. Washington D.C.: US Department of Health, Education, and Welfare. PHS Publication No 1103.
2. American Cancer Society. (2025). Key Statistics for Lung Cancer.  Retrieved October 19, 2025, from https://www.cancer.org/cancer/types/lung-cancer/about/key-statistics.html
3. Siegel RL, Kratzer, TB, Giaquinto, AN, Sung, H, Jemal A. Cancer statistics, 2025. CA: A Cancer Journal for Clinicians 2025; 75(1):10–45. Last accessed May 6, 2025, from https://doi.org/10.3322/caac.21871
4. American Lung Association. State of Lung Cancer, 2024. How does your state compare. Retrieved October 14, 2025 from https://www.lung.org/research/state-of-lung-cancer/states/michigan
5. Environmental Protection Administration. (2025). Health Risk of Radon. Retrieved October 19, 2025, from https://www.epa.gov/radon/health-risk-radon
6. Environmental Protection Administration. (2025). Home Buyer’s and Seller’s Guide to Radon. www.epa.gov/system/files/documents/2024-11/2024-buying-a-new-home-how-to-protect-your-family-from-radon_0.pdf
7. Committee on Health Risks of Exposure to Radon. (1999). Health Effects of Exposure to Radon: BEIR VI. Washington D.C. National Academies Press. 
8. Centers for Disease Control and Prevention (CDC). Lung Cancer Risk Factors. 2025. Retrieved October 17, 2025, from  https://www.cdc.gov/lung-cancer/risk-factors/index.html
9. Alberg, A.J., Ford, J.G., Samet, J.M., et al. (2007). Epidemiology of Lung Cancer: ACCP Evidence-based Clinical Practice Guidelines (2nd edition). Chest. 132 (3 Supplement): 29S-55S. doi: https://doi.org/10.1378/chest.07-1347
10. Madrigal, J.M. , Flory, A. , Fisher, J.A. , Sharp, E. , Graubard, B.I. , Ward, M.H. , Jones, R.R. (2024). Sociodemographic inequities in the burden of carcinogenic industrial air emissions in the United States. Journal of the National Cancer Institute. 2024 January 5;116(5):737–744. doi: 10.1093/jnci/djae001
11. Cheeseman, M.J., Ford, B., Anenberg, S.C., Cooper, M.J., Fischer, E.V.,  Hammer, M.S., Magzamen, S., Martin, R.V., van Donkelaar, A., Volckens, J., Pierce, J.R. (2022) Disparities in Air Pollutants Across Racial, Ethnic, and Poverty Groups at US Public Schools Geohealth.. 2022 December 1;6(12):e2022GH000672. doi: 10.1029/2022GH000672
12. National Cancer Institute. Lung Cancer Prevention (PDQ®)–Patient Version. Retrieved October 17, 2025 from https://www.cancer.gov
13. World Health Organization. Ambient (Outdoor) Air Pollution. Retrieved October 17, 2025 from https://www.who.int.  
14. Jazowski, S.A., Nayak, R.K. and Dusetzina, S.B. (2024). The high costs of anticancer therapies in the USA: challenges, opportunities, and progress. National Review of Clinical Oncology.  October 4;21(12):888–899. doi: 10.1038/s41571-024-00948-1
15. National Cancer Institute. Targeted Therapy for Cancer. Available at: Retrieved October 17, 2025 from https://www.cancer.gov/about-cancer/treatment/types/targeted-therapies
16. American Cancer Society. Survival Rates for Lung Cancer. Retrieved October 19, 2025, from https://www.cancer.org.  
17. U.S. Preventive Services Task Force. Lung Cancer: Screening. Recommendation Statement. Retrieved October 19, 2025, from  https://www.uspreventiveservicestaskforce.org  
18. U.S. Department of Health and Human Services. The Health Consequences of Smoking—50 Years of Progress: A Report of the Surgeon General. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health; 2014.
19. U.S. Environmental Protection Agency (EPA). Health Risk of Radon. 2024. Retrieved October 19, 2025, from https://www.epa.gov/radon/health-risk-radon
20. National Cancer Institute. Radon and Cancer. Updated 2024. Retrieved October 19, 2025, from https://www.cancer.gov/about-cancer/causes-prevention/risk/substances/radon/radon-fact-sheet
21. Centers for Disease Control and Prevention (CDC). Radon in Homes and Buildings. Updated 2023. Retrieved October 19, 2025, from: https://www.cdc.gov/radon
22. World Health Organization (WHO). Handbook on Indoor Radon: A Public Health Perspective. Geneva: World Health Organization; 2009.
23. State of Michigan Department of Environment, Great Lakes, and Energy.(2025). Michigan Indoor Program Overview. Retrieved October 19, 2025, from https://www.michigan.gov/egle/about/organization/materials-management/indoor-radon
24. Daniels RD, Schubauer-Berigan MK. RADON IN US WORKPLACES: A REVIEW. Radiat Prot Dosimetry. 2017 Nov 1;176(3):278-286. doi: 10.1093/rpd/ncx007
25. RCPD, Reducing the Risk from Radon: Information and Interventions – A Guide for Health Care Providers, CRCPD Publication 20-3, Revised September 2020. Retrieved October 19, 2025, from http://www.radonleaders.org/sites/default/files/2020-11/HCProvGuide%20Update%209-17-20.pdf
26. Luo YH, Luo L, Wampfler JA, Wang Y, Liu D, Chen YM, Adjei AA, Midthun DE, Yang P. (2019) 5-year overall survival in patients with lung cancer eligible or ineligible for screening according to US Preventive Services Task Force criteria: a prospective, observational cohort study. Lancet Oncology. Aug;20(8):1098-1108. doi: 10.1016/S1470-2045(19)30329-8.
27. Smolle, E. and Pichler, M. (2019). Non-Smoking-Associated Lung Cancer: A Distinct Entity in Terms of Tumor Biology, Patient Characteristics and Impact of Hereditary Cancer Predisposition. Cancers. February 10;11(2):204. doi: 10.3390/cancers11020204
28. University of Michigan Health. (2025). Lung Cancer Screening.Retrieved October 19, 2025, from https://med.umich.edu/1libr/Pulmonary/LungCancerScreening.pdf
29. Michigan Department of Health and Human Services. (2019). Lung Cancer in Michigan. Retrieved October 19, 2025, from https://www.michigan.gov/-/media/Project/Websites/mdhhs/Folder3/Folder98/Folder2/Folder198/Folder1/Folder298/lung_cancer_2019.pdf?rev=960eae36387e4dcfb2e92c958506559a
30. State of Michigan. (2025).Lung Cancer in Michigan. Retrieved October 19, 2025, from  https://www.michigan.gov/-/media/Project/Websites/mdhhs/Folder3/Folder98/Folder2/Folder198/Folder1/Folder298/lung_cancer_2019.pdf?rev=960eae36387e4dcfb2e92c958506559a
31. Colacino, J. (2025). Hidden dangers: The cancer risks of environmental injustice. Retrieved October 13, 2025, from https://sph.umich.edu/pursuit/2024posts/hidden-dangers-the-cancer-risks-of-environmental-injustice.html
32. HenryFord.com. (2025). Researchers link air pollution to rising lung cancer risk in non-smokers. Retrieved October 13, 2025, from https://www.henryford.com/news/2025/10/air-pollution-and-rising-lung-cancer
33. Michigan Department of Health and Human Services (MDHHS). (2025). Michigan Cancer Dashboard: Lung Cancer in Michigan. Retrieved October 13, 2025, from https://www.michigan.gov/mdhhs/keep-mi-healthy/communicablediseases/epidemiology/chronicepi/cancer-epidemiology/lung-cancer-dashboard
34. McAlpine, K. (2024). Faster, more sensitive lung cancer detection from a blood draw. Retrieved October 13, 2025, from https://news.engin.umich.edu/2024/10/faster-more-sensitive-lung-cancer-detection-from-a-blood-draw

Written 10/19/2025

Updated 11/10/2025