The U.S. Environmental Protection Agency (EPA) has officially moved to revoke the 2009 Endangerment Finding, a pivotal scientific conclusion that greenhouse gases—including carbon dioxide and methane—pose a significant threat to public health, and welfare. This repeal of EPA’s Endangerment Finding effectively dismantles the regulatory foundation used for decades to limit emissions, sparking immediate alarm among global health experts and medical professionals.
While the policy shift is often framed as a regulatory or economic victory, the medical community warns that the real-world consequences will be measured in human lives. For oncology specialists, this decision is not merely a political pivot but a direct blow to cancer care. By removing the legal mandate to curb greenhouse gas emissions, the administration is facilitating an increase in fossil fuel reliance, which exacerbates the environmental conditions that both cause cancer and disrupt the delivery of life-saving treatment.
As a physician with over a decade of experience in internal medicine and public health, I have seen how environmental determinants dictate patient outcomes. The intersection of climate policy and oncology is stark: when we allow the proliferation of carcinogenic pollutants, we increase the patient load in our clinics; when we ignore the volatility of a warming planet, we jeopardize the stability of the treatment schedules those patients rely on for survival.
Fossil Fuels and the Rise of Environmental Carcinogens
The link between the burning of fossil fuels and the development of cancer is well-documented in global health literature. The International Agency for Research on Cancer (IARC) has previously classified outdoor air pollution, primarily driven by fossil fuel combustion, as carcinogenic to humans. While tobacco remains the primary driver of lung cancer, the impact of air pollution is staggering; research indicates that 14% of all lung cancer deaths worldwide are attributed to air pollution. Crucially, this pollution increases mortality rates even for patients who have never smoked.
The risk extends beyond the lungs. Evidence suggests that air pollution contributes to higher rates of colon, breast, and head and neck cancers. The methods used to extract these fuels create localized health crises. Epidemiologic data has linked the prevalence of childhood leukemia to residents living in close proximity to fracking sites, likely due to the poor air quality resulting from drilling and extraction operations.
The climate crisis also manifests in the increasing frequency and intensity of wildfires, which release massive plumes of particulate matter. Recent data shows that air pollution from wildfires in Canada spread across borders, contributing to an estimated 70,000 deaths worldwide. For cancer patients, the danger is acute; exposure to wildfire smoke following curative surgery has been shown to worsen survival rates for those battling lung cancer.
How Climate Volatility Disrupts Precision Oncology
Cancer treatment is not a flexible process. This proves a precisely calibrated sequence of interventions—chemotherapy, radiation, and immunotherapy—that must follow strict schedules to be effective. Even a short delay in consecutive daily treatments can significantly diminish the probability of a successful outcome. Climate-driven disasters, such as the hurricanes and floods that are becoming more frequent, create catastrophic interruptions in this care.
When natural disasters strike, the impact on clinical infrastructure is immediate. Facilities often lose power and water, and critical radiotherapy equipment can be damaged or rendered inoperable. Beyond the hardware, the human element is compromised: skilled oncology staff may be unable to reach their workplaces, and the delivery of essential medications is frequently delayed. These disruptions also result in missed screenings for colorectal, cervical, breast, and skin cancers, delaying early detection when it is most curative.
The ripple effects of these disasters often extend far beyond the initial impact zone. A poignant example occurred following 2018’s Hurricane Maria in Puerto Rico, which forced the closure of factories producing intravenous (IV) saline bags. This led to a nationwide shortage in the U.S., forcing hospitals to ration care and implement suboptimal treatment workarounds for cancer patients who required hydration and IV drug administration for months according to reports from healthcare providers.
The Conflict Between Policy and Peer-Reviewed Science
The original 2009 Endangerment Finding was not an arbitrary policy; it was a conclusion rooted in credible, peer-reviewed science. This finding has survived multiple legal challenges in court due to the strength of the underlying evidence. However, the current repeal relies on a report authored by known climate contrarians—findings that have been roundly rejected by the broader scientific community.
The disconnect between official policy and scientific consensus is profound. In September 2025, the National Academy of Sciences issued a report specifically to inform the EPA’s deliberations, which not only supported the original 2009 finding but reported that the evidence had grown even stronger in the intervening years via the National Academies.
Public and professional opposition to the repeal has been overwhelming. More than 1,000 scientists, economists, and public health experts warned the EPA of the severe risks associated with climate change. The EPA received over 570,000 public comments opposing the repeal, though only a tiny fraction—approximately 5.4%—of those comments have been publicly released by the agency.
Key Impacts of the Repeal on Public Health
| Risk Factor | Direct Impact on Oncology | Systemic Consequence |
|---|---|---|
| Increased Emissions | Higher exposure to carcinogenic air pollutants | Rise in lung, colon, and breast cancer rates |
| Climate Volatility | Interruption of calibrated treatment schedules | Decreased patient survival rates post-surgery |
| Infrastructure Damage | Loss of power/water at radiotherapy centers | Delayed screenings and early detection |
| Supply Chain Failure | Shortages of critical IV fluids and medications | Rationing of care and suboptimal workarounds |
The Path Forward for Healthcare Advocacy
The repeal of EPA’s Endangerment Finding represents a shift toward official climate denial, but the medical community cannot afford to be silent. Groups such as Oncology Advocates United for Climate and Health-Int’l (OUCH International) continue to highlight the toll that environmental degradation takes on cancer patients and their families. For those of us in the medical field, the mandate is clear: we must advocate for policies that prioritize the well-being of millions over the short-term interests of the fossil fuel industry.
The stakes of this policy shift are not theoretical. They are visible in every clinic where a patient presents with a pollution-linked malignancy and in every hospital struggling to maintain care during an extreme weather event. The lack of scientific rigor in the repeal process is a departure from the Code of Public Health Ethics and the standards for humanitarian responses established by the Sphere Charter.
As the administration continues to dismantle climate research capabilities and restrict public access to environmental data, the burden of proof shifts to the healthcare community to document and communicate the human cost of these decisions. We must demand that the EPA re-engage with medical and public health experts to restore a policy framework that protects the most vulnerable among us.
The next critical checkpoint for this issue will be the inevitable legal challenges brought by state attorneys general and environmental advocacy groups, who are expected to file suits to reinstate the 2009 finding based on the National Academy of Sciences’ 2025 evidence. We will continue to monitor these filings and the resulting court orders.
Do you believe healthcare providers should have a larger role in shaping environmental policy? Share your thoughts in the comments below or share this article to raise awareness about the link between climate policy and cancer care.