Climate change and cancer: the Environmental Justice perspective

Abstract

Despite advances in cancer control—prevention, screening, diagnosis, treatment, and survivorship—racial disparities in cancer incidence and survival persist and, in some cases, are widening in the United States. Since 2020, there’s been growing recognition of the role of structural racism, including structurally racist policies and practices, as the main factor contributing to historical and contemporary disparities. Structurally racist policies and practices have been present since the genesis of the United States and are also at the root of environmental injustices, which result in disproportionately high exposure to environmental hazards among communities targeted for marginalization, increased cancer risk, disruptions in access to care, and worsening health outcomes. In addition to widening cancer disparities, environmental injustices enable the development of polluting infrastructure, which contribute to detrimental health outcomes in the entire population, and to climate change, the most pressing public health challenge of our time. In this commentary, we describe the connections between climate change and cancer through an Environmental Justice perspective (defined as the fair treatment and meaningful involvement of people of all racialized groups, nationalities, or income, in all aspects, including development, implementation, and enforcement, of policies and practices that affect the environment and public health), highlighting how the expertise developed in communities targeted for marginalization is crucial for addressing health disparities, tackling climate change, and advancing cancer control efforts for the entire population.

Advances in cancer prevention, screening and diagnosis, treatment, and survivorship care have led to substantial improvements in cancer control (1). However, these advances have not been distributed equally, with disparities in cancer risk, access to care, and outcomes not only persisting but also sometimes widening in the United States (2,3).

Health disparities are a specific type of deleterious health difference that affects groups of people who have been subjected to systemic discriminatory or exclusionary social and/or economic obstacles to health (4,5). Race is the main characteristic historically linked to discrimination and exclusion in the United States, where exposure to different forms of racism leads to worse cancer incidence, access to care, and mortality risk among individuals racialized as Black, Latinx, and Native American (6-9).

In addition to limiting our progress toward equity, racism also enables environmental degradation, limiting our collective progress toward reducing cancer burden in the entire population. Discriminatory policies and practices enable the development of polluting infrastructure in and near communities targeted for marginalization (10). However, individuals from all socioeconomic and racialized backgrounds are exposed to the ensuing environmental hazards, which cannot be confined to the communities where polluting infrastructure is sited (11).

Further, polluting industries contribute to climate change, the most pressing public health issue of our time (12). Climate change exemplifies how environmental injustices spill over from targeted communities and present hazards to the entire population, with grave implications for cancer control efforts (13,14). Vulnerability to environmental hazards, including climate change, is determined by different levels of exposure, sensitivity, and adaptive capacity in the population (15). Structural racism concentrates the conditions that increase vulnerability to the health hazards of climate change in communities targeted for marginalization (5). Thus, structural racism is a root cause of cancer disparities and is a threat amplifier for environmental hazards among communities targeted for marginalization in the era of climate change (12).

One way cancer researchers and oncology care professionals can contribute to dismantling structural racism is by incorporating an Environmental Justice perspective in research and professional activities. Environmental Justice is defined as the fair treatment and meaningful involvement of people of all racialized groups, nationalities, or income, in all aspects (eg, development, implementation, enforcement) of policies and practices that affect the environment and public health (16). For cancer researchers and oncology care professionals, incorporating an Environmental Justice perspective would include a shift toward centering the conditions imposed on individuals experiencing cancer disparities and increased climate vulnerability, as well as meaningfully incorporating the expertise coming from individuals from communities targeted for environmental injustices, who have been identifying health concerns associated with the development of polluting infrastructures for decades (10,11,17). Adopting an Environmental Justice perspective will not only contribute to shared goals of eliminating health disparities but also expand our access to the pool of knowledge and expertise that is vital for protecting the health and safety of the entire population, especially in the era of climate change.

Throughout this commentary, we intentionally use content and language that embodies the principles of antiracism, equity, and justice. As recommended by individuals from communities targeted for marginalization, we use terminology and language that centers the constraints imposed on communities as the root cause of health inequities (18,19). Additionally, we reference voices and scholarship of those who are directly impacted by discriminatory policies and practices. Further, when referring to racialized groups, we intentionally use “white” lowercase as a way to decenter whiteness and center racialized groups who have been subjected to marginalization, which are capitalized (eg, Black, Hispanic, Native American), and to avoid appropriating the work of Black scholars who shifted writing practices in favor of capitalizing Black.

Hindsight is 2020: Reckoning with the effects of racism on health

With the extrajudicial killing of Black individuals and the disproportionate impact of the COVID-19 pandemic on communities targeted for marginalization, 2020 ignited a reckoning among health professionals of the unequivocal impact of racism on health (20,21), resulting in strong commitments to dismantling structural racism (22).

Prior to 2020, few scientific articles even named racism as a driver of health disparities. Historically, medical and scientific work has been conducted primarily by individuals who benefit from white privilege, which limits the pool of knowledge and perspectives that determine the choice of research questions, shape study design, and set the norms of data interpretation (23). This monolithic structure has led to decades of research documenting racial disparities in cancer incidence and mortality rates with little progress toward equity (6,7,24,25). Since 2020, there has been progress towards acknowledging that simply focusing on improving diversity of study participants upholds the power structures perpetuating health disparities (26), and recognizing the importance of improving diversity, equity, and inclusion in the medical and scientific workforce (27-29).

However, increasing diversity of the workforce is not sufficient; a shift in underlying assumptions and professional practices is also necessary. For example, inherited problematic assumptions underlying how race is conceptualized and operationalized in research and medical practice upholds structural racism (and perpetuates disparities) in health (27). Race is a social construct without biological meaning (30). Although genetic ancestry can be a predictor of the prevalence of certain genetic variants associated with higher risk of developing certain diseases, including cancer, race is a poor proxy for genetic background (31). Therefore, genetic differences (or any discussion of innate biological differences) should not be presented as a potential cause of racial health disparities (32,33). Mentioning biological differences as a plausible cause of racial disparities upholds historical scientific racism, which attempted to establish race as an innate attribute to justify the exploitation of some individuals, and currently perpetuates a problematic narrative of race as a risk factor. The racist narrative of innate biological differences between racialized groups also deters from evaluation of relevant modifiable factors contributing to health disparities, such as lack of health insurance coverage (27).

In contrast to an analytical framework focused on reporting health disparities (instead of identifying and addressing drivers of health disparities, such as racism) (11), chasing biological explanations for observed disparities (34,35), or abandoning evaluation of disparities between racialized groups in research completely (31), an analytical framework that centers racism as the mechanism through which racial categorizations have biological consequences (and lead to health disparities between racialized groups) is increasingly recommended by researchers and professional societies (27,36-38).

There are several different forms of racism, all of which have health consequences (Figure 1) (39). Internalized racism consists of beliefs about racialized groups, which are learned and can become psychosocial stressors, leading to increased risk of depression, anxiety, and stress (40-42). Interpersonal racism are discriminatory interactions between individuals that reinforce hierarchical ordering of racialized groups (43,44), which can result in provision of substandard cancer care and worse outcomes among individuals racialized as Black or Latinx (43,45-61). For example, Black individuals are less likely to be included in clinical trials (62,63), and Black children are less likely to receive potentially superior radiation treatment even when enrolled in clinical trials where treatment assignments are supposed to be highly standardized (45). Institutional racism refers to unfair policies and discriminatory practices of institutions that restrict access to the goods, services, and opportunities of societies. For example, health-care institutions are less likely to accept and treat individuals with Medicaid health insurance coverage, a major source of coverage for people who are racialized as Black and Latinx, than individuals with other types of health insurance coverage (64). Systemic racism is the system in which policies, institutional practices, cultural representations, and other factors operate in overlapping and reinforcing ways to systematically disempower and endanger individuals from racialized groups subjected to marginalization. For example, the Social Security Act of 1935 created a system of employment-based health insurance coverage in the United States that excluded occupations predominantly held by individuals racialized as Black (2). This system interacts with discriminatory policies and practices in education and employment opportunities to restrict access to health insurance coverage for individuals racialized as Black (4,65). Importantly, health insurance coverage is one of the main determinants of racial disparities in receipt of recommended cancer care and resulting health outcomes (66-68).

Figure 1.

Exposure to different forms of racism (internalized, interpersonal, institutional, systemic, and structural) at each step of the cancer control continuum leads to racial disparities in cancer risk and outcomes.

Structural racism refers to the totality of ways in which societies reinforce racial hierarchy and discrimination through inequitable systems that are historically rooted and culturally reinforced. There are many ways in which structural racism manifests and impacts health (69). For example, racial residential segregation (70), which was established through institutional, interpersonal, and systemic racist policies and practices (10,71), created a platform for systemic disinvestment in neighborhoods targeted for marginalization that resulted in unequal exposure to health hazards [eg, air pollution (72-75), extreme heat (76), proximity to toxic waste sites (77), concentration of alcohol outlets (78), point-of-sale tobacco marketing (79-81)] and barriers in access to health resources [eg, clean water (82,83), healthy food options (84-86), built environment that promotes physical activity (87), neighborhood walkability (88), greenspaces (89,90)].

Increased exposure to environmental hazards and barriers in access to health resources led to greater prevalence of chronic health conditions among individuals from communities targeted for marginalization (91-94)—one of the main determinants of racial disparities in cancer mortality (95-97). Therefore, simply reporting “higher prevalence of smoking and comorbidities among Black individuals” (98) as a potential cause of racial disparities without naming racism and centering the conditions imposed on individuals from communities targeted for marginalization renders the systems of oppression invisible and promotes racial stereotypes (99), further contributing to structural racism (2,20,27,100,101).

In addition to perpetuating structural racism, simply reporting health disparities can undermine white individuals’ support to public health interventions potentially beneficial to individuals of all racialized groups, such as safety precautions proposed during the COVID-19 pandemic (102). In contrast, recognizing the structural causes (ie, social and environmental conditions imposed on racialized groups) as the fundamental causes of disparate health outcomes can help identify modifiable systemic factors contributing to health disparities, help dismantle structural racism, and facilitate the implementation of public health efforts that would improve the health of the entire population (103-106).

Recognizing the structural causes of health disparities can improve the health of the entire population because the same power structures enabling environmental injustices against predominantly Black, Latinx, and Indigenous communities also work to limit the choices available to predominantly white communities (107). For example, lung cancer mortality is higher in coal mining areas of Appalachia, which are predominantly white, even after adjusting for prevalence of obesity, smoking, and social determinants of health (108). Despite several documented hazards resulting from coal mining activities in the region, including exposure to carcinogens released into the air and water (109-111) and topology changes exacerbating the threats of flash floods (112), power structures based in wealth, rather than representation of affected communities, limit the options available to individuals in the region to reduce exposure to these health hazards (113,114). Therefore, identifying and opposing unjust power structures and discriminatory policies and practices that perpetuate environmental degradation is in the best interests of all people (11).

Environmental Justice and cancer

In the United States, environmental injustices (ie, the siting of polluting infrastructure near communities targeted for marginalization) have primarily targeted groups racialized as Black, Latinx, and Native American (115-117). Disproportionate exposure to the ensuing environmental hazards led to increased prevalence of health conditions in communities targeted for marginalization, as described previously, but also greater expertise gained from lived experiences. Such expertise is essential for advancing our understanding of environmental exposures relevant to cancer control efforts in the entire population, as well as identifying and implementing solutions that address the structural determinants of health.

The recent successful opposition to the development of the Formosa plastic plant in the Louisiana “Cancer Alley” (118,119), a predominantly Black community that has long recognized the health hazards resulting from pollution emitted by the more than 200 petrochemical plants and refineries in the area, exemplifies the value of expertise coming from communities targeted for marginalization to cancer control efforts (120). This environmental and public health victory also exemplified the importance of cancer research (eg, basic, epidemiologic) in supporting Environmental Justice efforts, as concerns about increased exposure to carcinogens were determining factors in the ruling.

Concerns about exposure to carcinogens were also relevant in the incident largely recognized as the start of the Environmental Justice movement in 1982 (121), when soil tainted with polychlorinated biphenyls, which are known human carcinogens (122), was dumped in Warren County, a predominantly Black community in North Carolina, after the Environmental Protection Agency waived its own health and safety criteria and the courts struck down lawsuits filed by the residents (10). Since then, the Environmental Justice movement has not only documented disproportionate exposure to environmental hazards among individuals from communities targeted for marginalization but also provided a framework for identifying and implementing solutions (16,115).

First, the Environmental Justice tenant of fair treatment facilitates the identification of modifiable factors rooted in structural racism that are driving cancer disparities and have the potential to improve health outcomes in the entire population. Take exposure to air pollution, for example. Highway construction was one strategy used to segregate neighborhoods (2,20), resulting in individuals from communities targeted for marginalization being disproportionately exposed to pollution from vehicle emissions (123). However, individuals of all racialized and socioeconomic backgrounds in the United States are exposed to air pollution from highway traffic (11,124). Therefore, air pollution is a modifiable factor contributing to cancer disparities and interventions to reduce exposure to air pollution have the potential to improve health outcomes for the entire population. Basic research and epidemiological studies were fundamental for establishing the carcinogenicity of air pollution (125,126) and provided the evidence base for passage of policy-level interventions to reduce exposure to air pollution in the entire population, such as the Clean Air Act in the United States (127). Moving forward, an Environmental Justice perspective can aid in identifying and implementing solutions arising from the fair treatment of individuals residing in targeted neighborhoods disproportionately exposed to air pollution, such as transforming transportation corridors (128), which would also reduce exposure to air pollution in the entire population.

Second, the Environmental Justice tenant of meaningful involvement would facilitate addressing the lack of diversity in the scientific and medical workforce, which is a concern at all career levels, from medical trainees to leaders of academic medical programs (129-131). In 2018, 8% of assistant professor positions in the United States were held by individuals racialized as Black (compared with 14.1% in the general population), 6% by individuals ethnicized as Latinx (compared with 18.3% in the general population), and less than 1% by individuals racialzied as Native Americans (compared with 1.7% in the general population) (16). Lack of representation is maintained by academic admissions processes that value the structural advantages conferred to privileged groups (132). Academic training can exacerbate representation issues as colonial narratives based on white-saviorism permeate scientific and medical training, portraying communities targeted for marginalization as places in need of saving (133).

This lack of diversity in the scientific and medical workforce also contributes to the inability of the health-care system to demonstrate trustworthiness (134-136). Lack of diversity and colonial narratives foster an approach to clinical practice and research that is centered on professional advancement and prioritizes prescribed solutions, dismissing local expertise and blaming individual behavior for health disparities, instead of valuing knowldege and expertise generated through lived experiences from the community (137).

Because individuals from communities targeted for marginalization are more likely to have been systematically excluded from the medical and scientific fields, professionals from underrepresented demographics are more likely to have gained experience working in real-world settings instead (138). These nonacademic settings (eg, government, societal service, community engagement) place less emphasis on publishing yet provide valuable training paths with greater understanding of structural determinants of health and modifiable factors relevant to cancer control efforts. However, the current focus on publication citations as a metric for expertise (139), combined with the prioritizations of training early career individuals from diverse backgrounds as the main strategy to demonstrate commitment to dismantling structural racism (140), largely ignores this expertise and perpetuates the assumptions upholding exclusionary professional networks. Improving representation and fostering meaningful involvement would not only improve the ability of the medical and scientific fields to demonstrate trustworthiness but also broaden the pool of knowledge and perspectives available to these fields (139,140), improving our collective ability to identify solutions vital for improving the health of the entire population (141,142), especially in the era of climate change.

Exemplifying the types of actions that center meaningful involvement—and therefore contribute to dismantling structural racism in research at all career levels—leaders at the National Science Foundation and other institutions have recently shifted toward including nonacademic contributions as evaluation criteria for the allocation of research funds (139). Further, several peer-review journals implemented changes that facilitate the inclusion of expertise developed by individuals from underrepresented backgrounds into peer-reviewed publications, facilitating knowledge (through information sharing) and professional advancement (28). Such efforts are extremely important because lack of diversity also hinders innovation because it limits the pool of knowledge, talent, and perspectives available in the field (29,141,142).

Therefore, applying an Environmental Justice perspective to all professional activities through centering the tenants of fair treatment and meaningful involvement would not only help identify and address structural factors contributing to cancer disparities, environmental degradation, and the resulting health threats for the entire population but also promote innovation, which is especially needed in the era of climate change (14).

Climate change and cancer

Climate change impacts cancer control efforts at every step of the cancer care continuum (13,14), from increasing cancer risk to adversely affecting receipt of recommended prevention (143,144), screening, and early detection (145) to treatment and survivorship care (Figure 2) (146). First, climate change alters the frequency and behavior of extreme weather events, [eg, increasing water capacity of hurricanes (147,148), lengthening of the wildfire season] (149) making it harder for communities to prepare and respond to increasingly unpredictable circumstances (150). Case in point, human-induced climate change made Hurricane Harvey’s record-breaking rainfall accumulation 3.5 times more likely to occur (151). The ensuing floods inundated chemical plants, oil refineries, and Superfund sites, releasing large amounts of carcinogens into the Houston community (152), exemplifying how climate change can impact cancer prevention efforts (Figure 2). The carcinogens released included benzene, which causes acute myeloid leukemia (153); polycyclic aromatic hydrocarbons, which are associated with increased risk of skin, lung, liver, bladder, and stomach cancers (154); polychlorinated biphenyls, which are associated with increased risk of developing cancers of the liver and the immune system (122); and dioxins, which are associated with increased risk of all types of cancer and can remain in the environment for decades (155).

Figure 2.

Climate change and cancer. Each step of reliance on fossil fuels releases carcinogens in neighboring communities and greenhouse gases in the atmosphere, which contribute to climate change. Climate change alters the behavior of extreme weather events making it harder for communities to prepare and respond to increasingly unpredictable circumstances, leading to disruptions in access to care and exposure to hazardous materials during disasters. Further, individuals diagnosed with cancer have increased vulnerability to the threats of climate change.

Second, Hurricane Harvey also illustrated how our reliance on fossil fuels is a shared cause of climate change and increased exposure to carcinogens (Figure 2), as Houston is one of the largest petrochemical hubs in the United States (156). Even in the absence of disasters, individuals residing near fossil fuel infrastructure sites are exposed to air contaminated with benzene (157-160), polycyclic aromatic hydrocarbons (161, 162), and fine particulate matter (163-166), all known carcinogens (126,153,154). Finally, the same air pollution from fossil fuel consumption that is driving the greenhouse effect also increases lung cancer risk (125,126). Carcinogens released at each step of the fossil fuel infrastructure—from extraction, to consumption, to waste management—all impact cancer control efforts (Figure 2).

Third, by changing the frequency and behavior of extreme weather events, climate-driven disasters can also disrupt access to health care (14), including cancer treatment (Figure 2) (167). For example, lung cancer patients receiving radiation treatment at a facility impacted by a hurricane had worse overall survival than similar patients who completed treatment at the same facility but in the absence of climate-driven disasters (146).

Fourth, cancer diagnosis and treatment have physical, psychological, and socioeconomic consequences, which increase vulnerability to the health hazards of climate change (Figure 2) (150). Some chemotherapy agents can impair body thermoregulation, making patients with cancer more vulnerable to extreme high or low temperatures (eg, heatwaves, winter storms) (168). Because chemotherapy targets rapidly dividing cells, it can lead to a reduction in the number of infection-fighting white blood cells, increasing the risk of infections when people are exposed to contaminated water during flooding events (169,170). The mental health conditions frequently associated with cancer treatment and survivorship, including anxiety and depression (171), are similar to the mental health consequences associated with exposure to climate-driven disasters (172,173), compounding the detrimental mental health risks (174). Moreover, cancer diagnosis, treatment, and survivorship care are associated with financial hardship (175), which limits the adaptive capacity, such as the ability to evacuate, stockpile food, or adapt housing infrastructure (eg, use air conditioning during heatwaves, install special air filters during wildfires).

Vulnerability to environmental hazards is determined by different levels of exposure, sensitivity, and adaptive capacity of the population (Figure 3) (15). By influencing levels of exposure, sensitivity, and adaptive capacity, structural racism compounds the vulnerabilities posed by cancer diagnosis and treatment among individuals from communities targeted for marginalization (5,176). As mentioned above, structural racism created a platform for systemic disinvestment in communities targeted for marginalization, leading to increased risk of exposure to environmental hazards, including extreme heat (76), as well as increased prevalence of chronic health conditions (91-94), leading to increased sensitivity among individuals from communities targeted for marginalization (Figure 3). Finally, structural racism creates barriers in access to resources (4,20,71), limiting the adaptive capacity of individuals from communities targeted for marginalization (Figure 3) (15).

Figure 3.

Structural racism concentrates the conditions that determine vulnerability to environmental hazards, including climate change. Structural racism created a platform for systemic disinvestment in communities targeted for marginalization that results in increased exposure to environmental hazards, increased sensitivity to climate hazards, and decreased adaptive capacity to cope with hazards, the conditions that determine vulnerability to environmental hazards, including the health threats of climate change.

The hierarchical categorization of individuals that is at the root of structural racism also permeates other systems of discrimination that value individuals based on gender (patriarchy), wealth (classism), nationality (xenophobia), and so forth. These systems intersect to further disadvantage certain racialized groups (176), creating barriers in access to resources and limiting options available to individuals during crises (5).

Although it is important to recognize that, because of discriminatory policies and practices, individuals from communities targeted for marginalization are impacted first and most by environmental hazards, climate change works as a threat amplifier for the challenges faced by individuals diagnosed with cancer of all racialized and socioeconomic backgrounds. Conversely, it is exactly because individuals from communities targeted for marginalization are exposed first and most that adopting an Environmental Justice perspective in cancer research and oncology practice is crucial not only for addressing disparities but also for advancing knowledge and improving innovation in every aspect of research and oncology practice.

For example, adopting an Environmental Justice perspective in every professional activity will expand the pool of talent and expertise and improve our collective ability to determine the oncogenic properties of environmental contaminants, characterize the health hazards associated with exposure to environmental hazards (eg, proximity to polluting infrastructure, extreme weather events), and ultimately contribute to the evidence base needed to implement national, state, and local solutions that protect the health and safety of the entire population.

Conclusion

Structural racism is a root cause of cancer disparities and environmental injustices in the United States. Because of discriminatory policies and practices, polluting infrastructure is more likely to be developed in proximity to communities targeted for marginalization (ie, environmental injustice). However, the resulting environmental hazards are not confined within the borders of these communities and have detrimental health consequences for individuals of all racialized and socioeconomic groups. Climate change exemplifies the spillover effects of environmental injustices because it impacts each step in the cancer care continuum and has grave implications for cancer control efforts in the entire population. Therefore, incorporating the Environmental Justice tenants of fair treatment and meaningful involvement in cancer research and oncology practice would not only advance health equity but also improve our ability to identify and address structural factors contributing to worse cancer risk and outcomes in the general population. Expanding the pool of knowledge and perspectives to include the expertise coming from individuals from underrepresented backgrounds, who have been impacted first and worst from threats posed by environmental hazards and structural determinants of health, will be vital for our collective progress in the fight against cancer, especially in the era of climate change.

Data availability

No data sources or analyzes were used in the article.

Author contributions

Leticia Nogueira, PhD, MPH (Conceptualization; Writing—original draft; Writing—review & editing) and K. Robin Yabroff, PhD (Writing—original draft; Writing—review & editing).

Funding

None.

Conflicts of interest

Leticia Nogueira, a JNCI Associate Editor and author of this editorial, was not involved in the editorial review of the manuscript or decision to publish the commentary.

K. Robin Yabroff, a JNCI Deputy Editor and author of this editorial, was not involved in the editorial review of the manuscript or decision to publish the commentary.

Acknowledgements

The authors would like to thank Dr William Dahut for his constructive feedback on an earlier draft of this commentary.