Exploring the link between climate change and your health
December 18, 2024
Extreme weather is becoming all too common these days. The world experienced its warmest year on record in 2023, and 2024 is on track to surpass it, according to the World Meteorological Organization. February 2024 also brought the largest wildfire in Texas history, which razed more than 1 million acres of land. Meanwhile, in September and October of 2024, overwhelming floods and landslides in Nepal killed more than 200 people, and millions of Americans watched as hurricanes Helene and Milton pummeled the southeastern coast of the U.S.
As physicians, we recognize the toll these disasters and other climate-related issues are taking on human health. Greenhouse gas emissions, pollution, and environmental degradation can exacerbate cardiovascular and breathing disorders, induce heat-related illness, and propagate infectious diseases. In fact, The Lancet has declared climate change "the greatest global health threat facing the world in the 21st century."
Certain populations are more vulnerable than others. Children, elderly people, patients with chronic conditions, those of lower socioeconomic status, and residents of areas that are prone to disasters are notably more at risk. A recent UT Southwestern study published in the American Journal of Obstetrics & Gynecology also found that pregnant women who were exposed to elevated levels of air pollution were more likely to experience preterm births and their newborns were more likely to require neonatal intensive care.
With such high stakes, it's worth taking a closer look at a few ways climate change impacts the current and future needs of medicine and health care.
"Right now, we are in the Anthropocene Epoch, the time when the global environment changes have been driven by human activities, and it's already affecting human health. We are paying attention to this because it is something that will matter for future generations."
Air quality directly affects health
Pollutants are all around us, and they can have serious health consequences at high levels. Dust, pollen, chemical fumes, and vehicle exhaust are known to irritate the eyes and airways, cause inflammation, and aggravate pre-existing conditions such as chronic obstructive pulmonary disease (COPD)/emphysema, asthma, and cancer.
It’s not just your respiratory health at stake. Poor air quality is also hard on the heart, especially for those already living with cardiovascular diseases. High concentrations of particulate matter – a mixture of microscopic airborne pollutants – can raise the risk of heart attacks, arrhythmias, and other serious complications, according to the Environmental Protection Agency (EPA).
Depending on the size, these particles may get trapped in the alveoli in the lungs and pass through the bloodstream to other organs. According to the American Lung Association, even short-term exposure to particulate matter may be hazardous. It's been linked to premature deaths among older adults, adverse birth outcomes for newborns, and infant mortality.
Additionally, air quality typically worsens with heat. Sunlight and heat chemically react with nitrogen oxides and volatile organic compounds produced from industrial sources to form ground-level ozone, or "bad" ozone, a type of pollutant. Heat also drives up demand for electricity, forcing power plants to burn more fossil fuels and release more gases.
Warmer temperatures can also cause plants to release increased amounts of pollen and mold spores. According to the Asthma and Allergy Foundation of America, during previous years, early blooms of flowers extended pollen season by 11-27 days. As a result, even people who do not have a history of allergies might develop symptoms.
The good news is that many of us have a useful health and safety tool right in our pockets. Weather apps on our smartphones allow us to track the air quality index and notify us when we should stay indoors. Using N95 masks and high efficiency particulate air (HEPA) filters may help block airborne irritants from getting into our respiratory systems that can trigger asthma flare-ups or other symptoms.
We recommend patients keep their prescribed medications on hand and consult their primary care physicians to develop an asthma action plan in these cases.
The effects of extreme heat
Heat is “the leading cause of weather-related deaths," according to the World Health Organization, and data from the EPA shows that the frequency, duration, and intensity of heat waves to hit the U.S. each year has only climbed over the last 60 years.
Extreme heat puts stress on the body that affects multiple organ systems, including the heart, brain, lungs, muscles, and gut. Symptoms can range from mild to potentially deadly. Heat cramps and rashes often disappear without complications, but heat exhaustion – marked by dizziness or headache, weakness, and heavy sweating – can turn into heat stroke, which is signaled by neurological symptoms and constitutes a medical emergency.
In the U.S., the Department of Health and Human Services estimates heat killed about 2,300 people in 2023, and in many cases, cardiovascular illness was the primary cause of death. Under heat stress, blood vessels dilate, corresponding with a drop in blood pressure, and the heart must pump harder and faster to meet the body's needs. At the same time, dehydration can compound the problem and potentially cause kidney injury or other organ damage.
Extreme heat can also impact our health and well-being in less direct ways – draining power grids, disrupting food and water supplies, and overwhelming emergency health care providers and first responders. Also, if Earth's global surface temperature continues to rise, the U.S. Geological Survey (USGS) and NASA predict it will only lead to more devastating droughts, wildfires, tropical storms, and floods – all of which can cause mass injuries and fatalities and disrupt health systems and infrastructure.
Cities are considered literal hotspots. They form urban heat islands and experience higher temperatures because they generate and absorb heat at a greater capacity than rural regions due to denser populations, layout, activities, and construction materials.
On scorching summer days when some regions see temperatures over 100 degrees Fahrenheit, asphalt can easily reach a temperature 40-60 degrees hotter. This has led to reports of serious second- and third-degree burns if people fall to the ground. In 2022, one burn center in Arizona recorded 85 hospitalizations from heat-related burn injuries; seven people died.
In cases like these, awareness is the key to prevention. It's important to exercise caution when the heat index reaches the high 90s. Take frequent cooling breaks and drink plenty of water if you must be outdoors.
We encourage patients to familiarize themselves with warning signs of heat illness, including dizziness, headaches, nausea, and an accelerated heart rate. Applying wet cloths and water to the skin can effectively cool the body down, but changes in consciousness or cognition are sure signs that emergency medical help is needed.
Increased spread of disease
Changes to Earth's natural systems can also boost the spread of infections, according to a Nature Climate Change analysis, which determined more than half of known human pathogenic diseases can be aggravated by climate change.
In recent years, the Centers for Disease Control and Prevention (CDC) has noted an uptick in vector-borne diseases such as West Nile virus as higher temperatures and changing rainfall patterns allow mosquitoes and ticks to multiply faster and expand into new areas. One paper from the New England Journal of Medicine predicted that cases of dengue fever, West Nile, and malaria could climb over the next 80 years if preventive steps are not taken.
Studies also suggest warming temperatures and increased precipitation can promote the growth and spread of bacteria such as E. coli in agricultural products. Seasonal changes and human activities can disrupt animal behavior and viral stability, contributing to outbreaks of zoonotic diseases such as bird flu.
To protect yourself from disease-carrying insects and ticks, follow these tips:
- Avoid forested and bushy areas or places with overgrown grass where ticks and other mites may reside.
- Drain stagnant water from your property to discourage mosquitos from breeding.
- Install window and door screens to keep mosquitoes out of your home.
- Apply a DEET-based insect repellent or leave out bug traps to prevent bug bites. They should be safe to use as long as the manufacturer's directions are followed.
- Wear long-sleeved clothing when outdoors and avoid outside activities during dawn and dusk when mosquitoes are most active.
Warmer climate conditions could also contribute to bacterial growth and food- and water-borne illnesses, with the greatest burden falling on the most vulnerable populations.
Follow these CDC-approved safety tips to minimize your risk:
- Avoid lakes, ponds, and rivers that might contain unknown bacteria.
- Sign up for local official alerts to receive up-to-date water safety announcements. The EPA requires public water systems to provide customers with annual reports about their local water quality.
- Clean and maintain your home's pipes and water storage and filtering devices. If you notice a sudden change, you may contact your local utility provider or public health department for questions.
- Wash your hands thoroughly with water and soap before preparing food and after handling raw meat, seafood, or eggs.
- Keep raw food separated from cooked food. Clean and sanitize surfaces as you go.
- Use a food thermometer to ensure your food is cooked to a safe temperature that kills bacteria.
- Rinsing fruits and vegetables under running water may not remove all pathogens, but it can reduce the presence of dirt and germs.
Since the threat of climate-related health impacts is only predicted to increase over the coming years, it is important to be familiar with the various effects it can have on your health and ways to mitigate them.
To speak with an expert on infectious diseases or preventive care, call 214-645-8300 or request an appointment online.
