A growing body of evidence is pointing to the obvious ways in which climate change impacts the environment. But those of us who study the impact of climate change on health have noted that the long-term shifts in temperatures and weather patterns also have not-so-obvious, downstream health implications, specifically for cancer.
Here in South Florida, we are at ground zero of the global climate change issue. Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine is in an area that provides a unique opportunity to study and understand how changes occurring in the natural environment influence disease risk and outcomes for all people.
This includes people in the Miami-Dade County catchment area who may experience compounded effects, because they are already medically underserved and underrepresented.
A problem of global proportions
The fallout from climate change is happening worldwide.
Just think: The third consecutive dry season across the Horn of Africa has resulted in the worst climate-induced emergency in four decades, leading to malnutrition and soaring disease risk. In September 2021, 17 COVID-19 patients died when severe flooding inundated a hospital in the central Mexican state of Hidalgo.
And the wildfires that predictably and more frequently rage across the Western United States each year are fueling dangerous levels of pollutants, potentially increasing risks that include heart and lung disease.
Extremes of climate change
In the past two years, the U.S. has had a record number of severe weather events, from wildfires and ice storms to hurricanes, that each resulted in $1 billion or more in damages.
According to Gallup findings released in 2022, there were at least 20 such incidents in 2020 and 2021, versus nine or more events totaling $1 billion or more in damages each year since 2011.
One in three U.S. adults report they have been personally affected by an extreme weather event in the past two years, according to Gallup.
Studies suggest with very high confidence that climate change is leading to increased temperatures, and hence increased heat stress. Jane Gilbert, Miami-Dade County’s Chief Heat Officer, was the keynote speaker at the inaugural University of Miami Climate Resilience Academy Symposium in April 2022.
Among other points, she emphasized that hundreds of thousands of workers in South Florida are exposed to extreme heat while working outdoors. Vulnerable populations, such as manual or unskilled laborers, are disproportionately affected by extreme heat.
We also can say with high confidence that climate change is resulting in rising sea levels. A third major and well-recognized consequence of climate change is increased rainfall, which increases concerns about flooding and standing water, heightening the risk of vector-borne diseases.
We witnessed this with Tropical Storm Alex at the beginning of the 2022 hurricane season here in South Florida.
While people in many areas of the U.S. are worried about potential flooding, others are concerned about droughts, another well-recognized consequence of climate change.
Climate change might lead to more frequent extreme weather events. Take tropical storms and hurricanes, for example. Their average forward-motion speed may be slower in a warming world.
The consequences of slower-moving tropical cyclones include longer durations of wind damage and intense rainfall, leading to increased infrastructure damage and flooding. For urgent issues such as maintaining or evacuating hospitals, the duration of the storm’s impact is critically important.
As an extreme example, Hurricane Harvey sat over Houston for five straight days in 2017. The downstream effects of Harvey were flooded chemical plants, oil refineries, and Superfund sites, causing industrial pollution. Even hospital generators were flooded post-Harvey.
There are studies that have looked specifically at patients, including how these weather events create downstream effects such as reduced access to health care. For example, longer-lasting and potentially more devastating tropical storms and hurricanes can negatively impact care access and overall survival for lung cancer patients, researchers reported in JAMA in 2019.
Given the rising sea levels, coastal inundation from tropical cyclones may become worse in future years. Climate change may be increasing the proportion of major hurricanes (Category 3 and above), bringing more wind damage to residences, hospitals, and overall, although this data is based on one recent study and more research is needed.
Direct and not-so-direct impacts on cancer
An additional 250,000 people worldwide are expected to die annually between 2030 and 2050 because of climate change from malnutrition, malaria, diarrhea, and heat stress, according to the World Health Organization.
Climate change affects the social and environmental determinants of health—everything from clean air and safe drinking water to adequate food supply. It also affects such things as access to care, including cancer screenings.
For cancer risk specifically, it is safe to say that climate change can increase cancer risk through a variety of mechanisms, including increased UV exposure, risk of exposure to toxic chemicals, heat, reduced access to cancer screening and care, and more.
In the commentary “Climate Change and Cancer,” published in CA: A Cancer Journal for Physicians, authors write that climate change increases exposure to known carcinogens.
For example, wildfires release pollutants, such as particulate matter. We have found that heat and pollutant exposure from wildfires affect our first responders. Moreover, the foam they use to put out fires is a known carcinogen and may contaminate the groundwater.
It’s likely that the most impactful cancer challenge facing the world from climate change will be disruption to systems of cancer care, including diagnosis, treatment, and management, according to a review in The Lancet Oncology.
Examples include not only severe weather conditions that restrict access to care, but also damage to cancer centers, hospitals, laboratories, and other facilities that provide needed oncology services.
A not-so-obvious impact of climate change on health is climate gentrification, in which residents of places that are elevation secure (meaning they are at higher elevations where the risk of flooding is lower) are displaced from those areas.
That can diminish their ability to access health care including cancer preventive services and social support, which we know attenuates cancer risk and improves survivorship for people navigating a diagnosis.
In an example of gentrification, Little Haiti is one of the most elevation secure areas in all of Miami-Dade County. As a result, there is significant development occurring within the boundaries of this neighborhood that has traditionally been the largest enclave of Haitian settlement in the U.S.
That development is causing the outmigration of Haitian families who have lived in this community for decades. Consequently, they are being dislocated from health-promoting resources that are important for prevention and earlier detection of cancer.
There are additional consequences facing more vulnerable populations. For minorities, there are the compounding issues of increased risk, for a variety of other reasons that are broadly influenced by social determinants of health, and gentrification.
Add to all this what happens when we experience extreme weather and the issues are further compounded, with minorities at even greater risk.
We also know that minorities may be less likely to live in areas with abundant green space. Without natural tree cover, there is increased UV exposure. Increased UV exposure drives the risk of melanoma.
Melanoma in racial/ethnic minorities tends to be diagnosed at later stages, when treatment efficacy is lower. Part of that is because of a lack of awareness, both within communities and among physicians, about how melanoma may present in people with darker skin.
The Washington Post summed it up when it reported last year: “Racial minorities in the United States will bear a disproportionate burden of the negative health and environmental impacts from a warming planet, the Environmental Protection Agency said Thursday, including more deaths from extreme heat and property loss from flooding in the wake of sea-level rise.”
The time to act is now
This is a health crisis, and the time to act is now.
The National Cancer Institute (NCI) is taking great interest in the topic of climate change and cancer, and NCI-designated cancer centers around the nation, including Sylvester, are taking action.
“The NCI is interested in supporting research relevant to advancing the understanding of the effects of climate change on cancer risks, control, and survivorship, and ways to prevent or mitigate negative health effects,” according to the Notice of Special Interest: Climate Change and Health.
Hopefully, it’s not too little, too late. Addressing and limiting the impact of climate change on health will require great minds, lots of quality research, and collaboration.
An additional 250,000 people worldwide are expected to die annually between 2030 and 2050 because of climate change from malnutrition, malaria, diarrhea, and heat stress, according to the World Health Organization.
In 2022, the University of Miami hosted a daylong Climate and Health Symposium, during which researchers, clinicians, and policymakers gathered to examine how climate change and extreme weather pose a threat to public health across the globe.
Participants addressed the obvious and not-so-obvious effects of climate change on health. For example, using Florida data, one researcher presented a link between exposure to heat waves and premature births. Another investigator presented evidence about climate and COVID-19 incidence.
We are hosting other university-wide symposiums to bring faculty together, including those who do not regularly interact. For example, our Sylvester cancer faculty, clinicians, and researchers are collaborating with faculty from outside the cancer center and the medical school to identify problems and devise solutions.
Sylvester researchers are giving talks, including National Cancer Institute Dissemination and Implementation fireside chats on the topics of climate change, cancer, and health. We spoke at The American Society for Preventive Oncology 2022 annual meeting on such subjects as how climate change alters the behavior of extreme weather events and the resulting impact on cancer rates and outcomes.
Health systems, including cancer centers, should find ways to promote collaboration and action. We have been supporting a mechanism called U-LINK, an intermural funding opportunity to catalyze interdisciplinary collaboration around social issues like climate change.
This year’s focus was on resilience, and we funded three projects that were health specific, two of which had direct implications for cancer.
And of course, we have ongoing research programs looking at the impact of climate change on cancer and health.
Creating better access to health care by increasing the number of mobile medical units in vulnerable communities, building greener and more sustainable structures, and disseminating information on heat wave warnings in real time are just some of the strategies that can serve as a prescription to cure the climate crisis.
Cancer centers can start looking within their own walls to protect people and communities from the health impacts of climate change.
“Cancer care—including chemotherapy, immunotherapy, and surgery anesthetics; imaging devices; and radiation therapy equipment—contributes to greenhouse gas emissions and climate change,” according to The ASCO Post. “Studies have shown that the biggest contributors to the carbon footprint in the U.S. health care system are the hospital and pharmaceutical industry sectors, so optimizing operating room ventilation based on occupancy and demand and using more energy-efficient computed tomography and magnetic resonance imaging machines can help to reduce greenhouse gas emissions.”
“Although some may view these issues as beyond the scope of responsibility of the nation’s cancer treatment facilities, one need look no further than their mission statements, all of which speak to eradicating cancer,” according to “Climate change and cancer,” referenced above.
“Climate change and continued reliance on fossil fuels push that noble goal further from reach. However, if all those whose life work is to care for those with cancer made clear to the communities they serve that actions to combat climate change and lessen our use of fossil fuels could prevent cancers and improve cancer outcomes, we might see actions that address climate change flourish and the attainment of our mission to reduce suffering from cancer grow nearer,” the authors wrote.
