Oncologists can mitigate harm from climate change; Here is how

In September of 2021, an unprecedented event occurred that may have escaped your notice. The New England Journal of Medicine and over 200 other health care publications simultaneously published joint editorials alerting the greater medical community to the “catastrophic” public health and environmental impacts of climate change.¹ 

In the two years since the clarion bell was sounded, the trajectory of climate change has only accelerated. The United Nation’s Climate Change Conference (COP26) dramatically and emphatically reported “the burning of fossil fuels is killing us.” “Pollution… is an existential threat to human health and planetary health.”³

The NEJM echoed these words, stating that “climate change poses an existential threat to planetary life.”⁴ These declarations should be a wakeup call for oncologists to recognize the threats to our patients and ourselves and to take action.

There are good reasons that oncologists have been slow to wake up to the threats to our patients and ourselves, despite the incontrovertible evidence that climate change is real and is caused by humans. First and foremost, we are all busy—most of us see climate change as just one more item to add onto our already very busy plates.

In addition, the issue of climate change is overwhelming. It has been described as a “perfect problem,” with implications like those of a perfect storm—only, unlike a localized storm, this problem engulfs our entire world. 

Daniel Kahneman, Nobel Laureate in Economics, explains why action on climate change has been so elusive.⁵ Climate change is:

1. Remote. Its bigger effects are on people far away.
2. Global. It does not affect a single place.
3. Slow. Its impacts occur gradually, and its solutions have no deadlines.
4. Painful. It requires sacrifices now to avoid uncertain losses far in the future.
5. Complex, with no single cause, and no single solution.
6. Universal, with no obvious single enemy.
7. Controversial. The estimates of its effects are contested, and there are disagreements about what to do, because there are people and industries with interest in taking no action. 

More and more medical organizations and their members recognize the warming of the planet as a health issue. The Medical Society Consortium for Climate and Health is a U.S.-based non-profit organization dedicated to educating the public and policymakers in government and industry about the harmful human effects of global climate change. Its nearly 50 professional member health organizations and 75 affiliates signed its consensus statement.⁶

These societies include as members premiere cancer organizations in which many of us are members and/or volunteers (ASCO, ASTRO, SGO). Some of these societies have or are developing policy statements or white papers outlining how climate change will impact their patients and calling for action. 

The purpose of this editorial for the oncology community is to increase awareness of the imminent and future harms caused by climate change and fossil fuel emissions to our patients, our practices, our families and ourselves. As a call for individual and collective action, we also provide several specific steps for oncologists to consider adapting to mitigate the threats in front of us.

What is climate change?

Our climate has warmed about 1.1 degree Celsius (1.9 degrees Fahrenheit) since the industrial revolution began. The main culprit is greenhouse gasses (CO2, nitrous oxides, methane, and fluorinated gasses) in the atmosphere. These pollutants prevent the energy of the sun from escaping back into space, instead reflecting it as infra-red radiation back to earth. Excess greenhouse gasses (GHG) come almost exclusively from humans burning fossil fuel. 

Effects on health

The health impacts of this accelerating rise in temperature have been well studied. However, these consequences seem abstract as they are usually viewed from an environmental, political, or socioeconomic viewpoint. 

Despite the increasing recognition that climate change has an impact on health, there has been relatively little discussion within our cancer community as to how it will affect our patients and our practices. It is time to examine its impacts on cancer care. 

Air pollution

What does air pollution have to do with climate change? The burning of fossil fuels (coal, oil, and gas) is primarily responsible for air pollution, which both worsens climate change, and is worsened by climate change. 

Environmental scientists have established that air pollution has devastating consequences. Ambient air pollution is blamed for 7 million deaths worldwide, one in five deaths globally.⁷ The Global Burden of Disease 2017 Risk Study calls it out as the second most common cause of lung cancer, after smoking.  In the United States, polluted areas encompass both urban and rural locales (Cohen, 2017 #61).

In addition to greenhouse gasses, fossil fuels also emit particulate matter when burnt. Particulate matter (PM2.5) with diameters of less than 2.5 microns (or about 1/30th the width of a human hair) generated by fossil fuel combustion is of particular concern. These particles have been categorized as group 1 carcinogens by the International Agency for Research on Cancer (IARC).⁹

In addition to causing local inflammation and oxidative stress, these particles penetrate deep into the lung’s terminal bronchioles, and from there translocate into the circulation, causing systemic inflammation. A recent study found a significant association between PM2.5 levels and the incidence of lung cancer for 32,957 EGFR-driven lung cancer cases. 

In mice, inhalation of PM2.5 induces an inflammatory axis driven by IL1B, which is associated with the development of lung cancer. Mouse tumor formation was prevented by treatment with anti-IL1B therapy, suggesting a causal link.¹⁰ 

Do we know that lung cancer is related to air pollution? Numerous epidemiological studies have shown that people living in highly polluted areas are more likely to die of lung cancer than those who live in less polluted areas. At least six meta-analyses have concluded that the relative risk of dying of lung cancer ranges from 1.07 (95% CI: 1.01-1.13) to 1.16 (95%CI: 1.09-1.23). ^{11 12 13 14 15 16} 

Air pollution can cause lung cancer even in nonsmokers.¹⁷ For example, a meta-analysis showed that lung cancer risk associated with PM2.5 was greatest for former smokers [1.44 (95% CI: 1.04, 1.22)], followed by never-smokers [1.18 (95% CI: 1.00, 1.39)], and then current smokers [1.06 (95% CI: 0.97, 1.15).¹⁸ 

Other studies have shown the chances of having TP53 or KRAS mutations, adjusting for patient characteristics, other environmental factors, and neighborhood level socioeconomic status were increased in areas with higher PM2.5 exposure. 19 20 PM2.5 also adversely affects the prognosis of patients with existing lung cancer, and makes patients with lung cancer more susceptible to infections such as COVID-19. ^{21 22 23}

PM2.5 can also come from sources unrelated to energy production, such as wildfires, which are becoming more frequent because of climate change. The estimated mortality and morbidity attributable to smoke plumes in the U.S. is not just in the west—smoke can travel thousands of miles.²⁴ 

PM2.5 from wildfire smoke is more toxic than ambient air pollution, is mostly carbonaceous, and has more oxidative potential than ambient potential, thus causing more inflammation and oxidative stress.²⁵ Wildfire exposure has also been associated with increased incidence of lung cancer and brain tumors.²⁶

Extreme weather events 

Extreme weather events interrupt patient access to care and medications. These events can disable infrastructure and impair the ability to access cancer care, leading to delays and disruptions in treatment, increased morbidity, and death.^{27 28} 

For example, poorer outcomes were noted among patients with non-small cell lung cancer receiving definitive radiation therapy whose continuity of care was affected by hurricanes as compared to a matched cohort of patients who underwent treatment in the absence of such interruptions.²⁸ 

Weather events can derail drug supply chains leading to shortages, such as those that occurred in 2018 when Hurricane Maria struck Puerto Rico. After that event, the closure of factories that supplied the bulk of small volume IVs led to their reduced availability in the continental U.S. ²⁷ 

Treatment delays or interruptions for patients receiving chemotherapy for breast, colorectal, head and neck cancers, and gynecological cancers can result in worse survival outcomes. Following Hurricane Katrina, studies documented a 15% increase in breast and lung cancer mortality among cases diagnosed in exposed parishes.²⁷

Infrastructure damage due to flooding can result in loss of power, electricity, water, radiotherapy equipment, clinical facilities, medical records, and access to staff, as evidenced by such care impediments after Hurricane Katrina in 2005. Damage to communication systems can significantly impact workforce management and evacuation of patients and staff.²⁷ 

Research can be negatively impacted due to loss of data and biological samples, fewer studies, longer times to open studies, and longer times to accrual. MD Anderson Cancer Center now has a retractable wall surrounding it after Hurricane Allison decimated pathology specimens housed in basement storage facilities. 

Disparities 

The impact of climate change on cancer risk disproportionally plagues underserved populations and racial and ethnic minorities, including the socioeconomically disadvantaged,²⁹ people of color,³⁰ residents of low-income countries^{31, 32} and small island states,³³ Hispanic/Latinos (Demetillo, 2021 #941), American Indians, and Alaskan natives.^{34, 35} The 10 worst areas in the United States for air pollution are overwhelmingly in places where Black and Hispanic populations live, and thus are disproportionately impacted.³⁶ 

Individuals in resource deprived areas or those with lower educational levels and lower income levels have higher mortality and incidence rates from cancer than more affluent populations. There is excess risk across the cancer spectrum, but disparities are most marked for lung, colorectal, cervical, stomach, and liver cancer.²⁹ 

Data from the Black Women’s Health Study showed that lung cancer incidence was higher among Black women who have never smoked compared to women of other races who have never smoked.³⁷ Emissions produced by industry, light-duty gasoline vehicles, construction, and heavy-duty diesel vehicles trend higher in areas populated by disadvantaged minorities and are blamed as among the largest sources of cancer related health disparity.³⁰

Nearly all major emission categories—including across states, urban and rural areas; income levels; and exposure levels—contribute to the systemic PM2.5 exposure disparity experienced by people of color.³⁰

Action steps

So, what can we, as oncology health professionals, do? We can continue to assume that climate scientists and politicians will “take care of it”. But it is precisely because we care about our patients and ourselves that we need to get personally involved in climate advocacy. 

One of our most important roles is that of the educator. Margaret Mead, the famous cultural anthropologist, president of the American Association for the Advancement of Science, and recipient of the Presidential Medal of Freedom, once said, “Never doubt that a small group of thoughtful committed individuals can change the world. In fact, it’s the only thing that ever has.”

Although it may seem that individual actions by themselves are a drop in the bucket, each one has an impact on the warming of the climate that multiplies as the actions are more widely adopted.

Physicians and nurses are identified by the public as among society’s most trusted messengers. We are an educated community of educators. We have a voice that people will listen to when we speak out to our medical community (e.g. Grand Rounds, seminars), local community (letters to our local newspaper; community events; Townhall meetings, etc.), friends, and neighbors.

The U.S. health care sector is estimated to contribute 8% of all US pollution, including acid rain (12%), greenhouse gas emissions (10%), smog formation (10%), air pollutants (9%), stratospheric ozone depletion (1%), and carcinogenic and non-carcinogenic air toxins (1-2%).³⁸ 

If the world’s health services were a country, health care would be the fifth-largest carbon emitter on the planet (Harm, 2019 #239). The U.S. emissions accounts for 27% of the global healthcare footprint, the highest in the world.³⁹

These emissions are typically divided up into three areas. Emissions emanating directly from healthcare facilities and healthcare-owned vehicles make up about 17% of the sector’s worldwide footprint. Indirect emissions from purchased energy sources such as electricity, steam, cooling, and heating comprise another 12%. 

The major source of emissions—71%—is primarily derived from the healthcare supply chain through the production, transport, and disposal of goods and services, such as pharmaceuticals and other chemicals, food and agricultural products, medical devices, hospital equipment, and instruments.⁴⁰

Seven keys to lower emissions include: 

1. Powering healthcare with clean and renewable energy; 
2. Investing in zero emission buildings and infrastructure; 
3. Transitioning to zero emissions; 
4. Sustainable travel and transport; 
5. Providing health and sustainable food;
6. Incentivizing and producing low carbon pharmaceuticals;
7. Embracing sustainable healthcare management;⁴¹

It is estimated that if all U.S. hospitals adopted best practices, we would save $5 billion over five years, or $15 billion over 10 years, by reducing our energy use, providing better waste management, reprocessing single use devices, and improving operating room efficiencies alone (Kaplan, 2012 #240).

This is a tall order, but a few enterprises are taking action. Among these forward-looking organizations are Kaiser Permanente, Gundersen Clinic, Boston Medical Center, University of Pennsylvania, Harvard, and New York University. Each have already started to implement reforms with the goal of becoming carbon neutral.^{42, 43, 44, 45, 46}

Numerous organizations have called on the health care system to reduce pollution.^{47, 48} The U.S. Department of Health and Human Services has reopened their Health Sector Climate Pledge,⁴⁹ in which institutions are pledging to: 

1. Reduce organizational emissions by 50% by 2030 and achieve net-zero by 2050.
2. Designate an executive-level lead for their work on reducing emissions by 2023 and who will conduct an inventory of Scope 3 (supply chain) emissions by the end of 2024.
3. Develop and release a climate resilience plan for continuous operations by the end of 2023, anticipating the needs of groups in their community that experience disproportionate risk of climate-related harm.

As of 2022, 102 organizations representing 837 hospitals, including Beth Israel, Boston Children’s Hospital, Children’s National Hospital, Kaiser Permanente, NYU, Stanford, Tufts University of California Health, USC have committed themselves to these goals by signing the letter.

The National Academy of Medicine’s (NAM) Action Collaborative on Decarbonizing the U.S. Health Sector (Climate Collaborative) has convened a public-private partnership of leaders from across the health system committed to addressing the sector’s environmental impact while strengthening its sustainability and resilience. Members of the Climate Collaborative represent health and hospital systems, clinicians, private payers, biopharmaceutical and medical device companies, health care services, health professional education, academia, nonprofits, and the federal government. 

The goals are to improve health equity, by improving health care supply chain and infrastructure; health care delivery; health professional education and communication, and policy, financing, and metrics.⁵⁰

What can we do on a more local level? 

These initiatives require buy-in from—and therefore, interaction with—the leaders in the health system where each of us practice. Recently, the Joint Commission changed its plans to introduce proposed sustainability measures as optional because of pushback from senior hospital administrators who state that they are overwhelmed with workforce shortages and financial challenges.⁵¹

We need to work our health-care system administrators to find cost-neutral and/or cost-saving solutions. Resources are available to help institutions and health systems track GHG emissions and set reduction goals.^{52, 53, 40}

Personal actions, such as decreased use of combustion powered vehicles, more use of clean energy, reducing red meat intake, are, of course, important. However, arguably, both individual actions and promotion of systemic change are essential.⁵⁴ 

The collective actions of society have led us to this climate crisis. Although it may seem that individual actions by themselves are a drop in the bucket, each one has an impact on the warming of the climate that multiplies as the actions are more widely adopted. 

Advocacy

There are multiple ways to advocate for the health benefits of climate interventions locally and nationally. Numerous professional health organizations have organized on the local and national level to advocate for system wide policies which will impact the effect of these environmental challenges on the health of patients.  

Although the majority of these are related to climate change and health in general, more and more oncology health organizations are starting to recognize the effects of climate change on cancer patients. Individual members of these organizations can effectively lobby their local, state, and national representatives to recognize the problem and implement plans of action to harness it. 

Since most of these efforts focus on the specific concerns of their membership, other oncologists are initiating broader approaches.⁵⁵

Vote responsibly

In a non-partisan publication such as this one, it is always difficult to approach the political controversies our nation currently faces. Nevertheless, this is probably the most important area in which one can make an impact on protecting the environment for our cancer patients. 

We need to ask individuals who seek to represent us where they stand on climate change. Whenever you enter the voting booth, consider the impact your elected officials will have on how climate change is having on your patients.

There are many reasons for acting or for not acting. Among the impediments to action are political (“We do not want to disenfranchise our politicians, funders, or supporters, who may be on the other side of the argument.”), financial (“We can’t afford it” or “We rely on these partners for support”), logistical (“I’m too busy”), or nihilistic (“It’s too late; there’s nothing that can be done”) arguments. 

In our daily practices, we tend to focus on the problems and concerns of the patient in front of us. However, as oncology professionals, we need to step back and anticipate the broader problems our patients will soon be facing if we don’t act now.

We are calling for you to broaden your perspective to embrace a population health perspective. Although the link between cancer care and climate change has often been under-recognized, we need our cancer care leaders, organizations, cancer centers, and the rest of our stakeholders to mobilize toward education, research, and action in this critical space. 

Climate change impacts cancer care, and therefore it is “our” problem. As oncologists who care deeply about our patients, and as trusted messengers, it is our responsibility to our current and future patients to do whatever we can to prevent cancer and reduce its complications. 

We all took oaths to “first, do no harm.” We can prevent harm to our future patients by acting now. 

References

1. Atwoli L, Baqui AH, Benfield T, et al: Call for Emergency Action to Limit Global Temperature Increases, Restore Biodiversity, and Protect Health. N Engl J Med 385:1134-1137, 2021
2. CDC: Climate Effects on Health, in CDC (ed), 2022
3. Fuller R, Landrigan PJ, Balakrishnan K, et al: Pollution and health: a progress update. Lancet Planet Health 6:e535-e547, 2022
4. Morello-Frosch R, Obasogie OK: The Climate Gap and the Color Line – Racial Health Inequities and Climate Change. N Engl J Med 388:943-949, 2023
5. Why is it so difficult to change?, EkiVision#22, 2022
6. Health MSCoCa: Mission & Consensus Statement, 
7. Vohra K, Vodonos A, Schwartz J, et al: Global mortality from outdoor fine particle pollution generated by fossil fuel combustion: Results from GEOS-Chem. Environ Res 195:110754, 2021
8. Collaborators GRF: Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet 2018; 392: 1 392:1923-94, 2018
9. Loomis D, Grosse Y, Lauby-Secretan B, et al: The carcinogenicity of outdoor air pollution. Lancet Oncol 14:1262-3, 2013
10. Hill W, Lim EL, Weeden CE, et al: Lung adenocarcinoma promotion by air pollutants. Nature 616:159-167, 2023
11. Hamra g: Outdoor particulate matter exposure and lung cancer: a systematic review and meta-analysis. Environ Health Perspect. 122:906-911, 2014
12. Cui P, Huang Y, Han J, et al: Ambient particulate matter and lung cancer incidence and mortality: a meta-analysis of prospective studies. European Journal of Public Health 25:324-329, 2014
13. Yang W, al. e: An evidence-based assessment for the association between long-term exposure to outdoor air pollution and the risk of lung cancer. European journal of Cancer Prevention 25:163-172, 2016
14. Chen J, Hoek G: Long-term exposure to PM and all-cause and cause-specific mortality: A systematic review and meta-analysis. Environ Int 143:105974, 2020
15. Ciabattini M, Rizzello E, Lucaroni F, et al: Systematic review and meta-analysis of recent high-quality studies on exposure to particulate matter and risk of lung cancer. Environ Res 196:110440, 2021
16. Yu P, Guo S, Xu R, et al: Cohort studies of long-term exposure to outdoor particulate matter and risks of cancer: A systematic review and meta-analysis. Innovation (Camb) 2:100143, 2021
17. Turner MC, Andersen ZJ, Baccarelli A, et al: Outdoor air pollution and cancer: An overview of the current evidence and public health recommendations. CA Cancer J Clin, 2020
18. Hamra GB, Guha N, Cohen A, et al: Outdoor particulate matter exposure and lung cancer: a systematic review and meta-analysis. Environmental health perspectives 122:906-911, 2014
19. Erhunmwunsee L, Wing SE, Shen J, et al: The Association between Polluted Neighborhoods and TP53-Mutated Non-Small Cell Lung Cancer. Cancer Epidemiol Biomarkers Prev 30:1498-1505, 2021
20. Wing S, Jankowska M, al. e, et al: Neighborhood disadvantage is associated with KRAS‑mutated non‑small cell lung cancer risk. Journal of Cancer Research and Clinical Oncology, 2022
21. Eckel SP, Cockburn M, Shu YH, et al: Air pollution affects lung cancer survival. Thorax 71:891-8, 2016
22. Ou JY, Hanson HA, Ramsay JM, et al: Fine Particulate Matter Air Pollution and Mortality among Pediatric, Adolescent, and Young Adult Cancer Patients. Cancer Epidemiol Biomarkers Prev, 2020
23. Coleman NC, Burnett RT, Higbee JD, et al: Cancer mortality risk, fine particulate air pollution, and smoking in a large, representative cohort of US adults. Cancer Causes Control 31:767-776, 2020
24. O’Dell K, Bilsback K, Ford B, et al: Estimated Mortality and Morbidity Attributable to Smoke Plumes in the United States: Not Just a Western US Problem. GeoHealth 5:e2021GH000457, 2021
25. Aguilera R, Corringham T, Gershunov A, et al: Wildfire smoke impacts respiratory health more than fine particles from other sources: observational evidence from Southern California. Nature Communications 12:1493, 2021
26. Korsiak J, Pinault L, Christidis T, et al: Long-term exposure to wildfires and cancer incidence in Canada: a population-based observational cohort study. Lancet Planet Health 6:e400-e409, 2022
27. Man RX, Lack DA, Wyatt CE, et al: The effect of natural disasters on cancer care: a systematic review. Lancet Oncol 19:e482-e499, 2018
28. Nogueira LM, Sahar L, Efstathiou JA, et al: Association Between Declared Hurricane Disasters and Survival of Patients With Lung Cancer Undergoing Radiation Treatment. JAMA 322:269-271, 2019
29. Singh GK, Jamal A: Socioeconomic and Racial/Ethnic Disparities in Cancer Mortality, Incidence, and Survival in the United States, 1950–2014: Over Six Decades of Changing Patterns and Widening Inequalities. Journal of Environmental and Public Health 2017:1-19, 2017
30. Tessum CW, Paolella DA, Chambliss SE, et al: PM(2.5) polluters disproportionately and systemically affect people of color in the United States. Sci Adv 7, 2021
31. Primm KM, Zhao H, Hernandez DC, et al: Racial and Ethnic Trends and Disparities in NSCLC. JTO Clin Res Rep 3:100374, 2022
32. Chapman AR, Ahmed AK: Climate Justice, Humans Rights, and the Case for Reparations. Health and Human Rights Journal 43:81-94, 2021
33. Shultz JM, Sands DE, Kossin JP, et al: Double Environmental Injustice – Climate Change, Hurricane Dorian, and the Bahamas. N Engl J Med 382:1-3, 2020
34. Kratzer TB, Jemal A, Miller KD, et al: Cancer statistics for American Indian and Alaska Native individuals, 2022: Including increasing disparities in early onset colorectal cancer. CA Cancer J Clin 73:120-146, 2023
35. Ashing KT, Jones V, Bedell F, et al: Calling Attention to the Role of Race-Driven Societal Determinants of Health on Aggressive Tumor Biology: A Focus on Black Americans. JCO Oncol Pract 18:15-22, 2022
36. McCormick E: US neighborhoods with more people of color suffer worse air pollution. The Guardian, 2023
37. Erhunmwunsee L, Wing SE, Zou X, et al: Neighborhood disadvantage and lung cancer risk in a national cohort of never smoking Black women. Lung Cancer 173:21-27, 2022
38. Eckelman MJ, Sherman J: Environmental Impacts of the U.S. Health Care System and Effects on Public Health. PLoS One 11:e0157014, 2016
39. Eckelman MJ, Huang K, Lagasse R, et al: Health Care Pollution And Public Health Damage In The United States: An Update. Health Aff (Millwood) 39:2071-2079, 2020
40. Harm HCW: Global Road Map for Health Care Decarbonization: A navigational tool for achieving zero emissions with climate resilience and health equity, Climate-Smart Health Care Series, 2021
41. Harm HCW: A navigational tool for achieving zero emissions with climate resilience and health equity; green paper Numeber Two, Climate-Smart Health Care Series, 2021
42. Medical B: Sustainability. 
43. Sustainability P: Carbon Neutrality by 2042 (100 x 42). 
44. Tackling climate change to drive health and health equity, in Permanente K (ed), 2022
45. University H: Rising to the climate challenge, 
46. NYU: Climate Change. 
47. Dzau VJ, Levine R, Barrett G, et al: Decarbonizing the U.S. Health Sector – A Call to Action. N Engl J Med 385:2117-2119, 2021
48. Romanello M, Di Napoli C, Drummond P, et al: The 2022 report of the Lancet Countdown on health and climate change: health at the mercy of fossil fuels. Lancet 400:1619-1654, 2022
49. Services UDoHaH: Health sector commitments to emissions reduction and resilience. . Updated April 28, 2023. , 2023
50. Medicine NAo: Action Collaborative on Decarbonizing the US Health Care Sector, in NAM Grand Challenge on Climate Change HHaE (ed), 2023
51. Gliadkovskaya A: Facing industry pushback, Joint Commission plans to introduce proposed sustainability measures as optional, Fierce Healthcare, 2023
52. Landrigan PJ, Fuller R, Acosta NJR, et al: The Lancet Commission on pollution and health. Lancet 391:462-512, 2018
53. Quinlan D: Health Care climate change and an opportunity for a transformative leader ship, Health Care Without Harm, 2014
54. Dobson J, Cook S, Frumkin H, et al: Accelerating climate action: the role of health professionals. BMJ 375:n2425, 2021
55. Schiller J: Oncologists United for Climate and Health, joanhschiller@gmail.com