Comprehending Climate Change Implications in an Ever-Changing Healthcare System

How Does Climate Change Increase Healthcare Costs?

Rising global temperatures and poor air quality caused by multiple factors, such as pollution and particulate matter, increase healthcare costs and increase the chance of spreading infectious diseases.

Temperatures

An ongoing temperature analysis led by NASA’s Goddard Institute for Space Studies states that the average global temperature has increased by 1.1°C since 1880. Although the past decade was by far the hottest in recorded history, this decade is on pace to be even hotter.

Intense heatwaves driven by increased global temperatures put people at increased risk of heat-related illnesses such as heat cramps, heat exhaustion, dehydration, and heatstroke, which worsen a range of cardiovascular ailments that can lead to increased hospital and emergency room visits and death.

A Nature Climate Change study found that 37% of all heat-related deaths are directly attributable to anthropogenic climate change from 1991 to 2018.

Air Quality and Pollution

Because not all pollution is noticeable or visible, air quality and pollution are commonly overlooked environmental health hazards that threaten respiratory health. In 2019, 99% of the world population lived in regions where the WHO air quality guidelines levels were not met.

Air pollution exposure is linked to oxidative stress and inflammation in human cells, which may lay a foundation for chronic disease and cancer development.

Air pollution — a mix of hazardous substances from natural and human-made sources — is caused by vehicle emissions, heating and cooling homes, manufacturing and power-generation byproducts, and fumes from chemical production.

In 2013, the International Agency for Research on Cancer of the World Health Organization (WHO) categorized air pollution as a human carcinogen.

Air pollution impacts lung development and plays a role in developing emphysema, asthma, chronic obstructive pulmonary disease (COPD), and other respiratory diseases.

A 16-year Environmental Health study indicated long-term health consequences by discovering an association between lung cancer incidence and increased reliance on coal energy production.

Particulate Matter (PM)

Particulate matter (PM), composed of chemicals like nitrates, carbon, sulfates, or mineral dusts, is found in industrial and vehicle emissions from fossil fuel combustion, burning organic matter, and cigarette smoke. A 2019 study published in Toxicology Applied Pharmacology found that early-life inhalation exposure to dust created by mining operations alters lung function and development.

Fine particulate matter (PM2.5, 2.5 microns or less in diameter), a subset of PM, is 30 times thinner than a human hair and can be inhaled deeply into lung tissue, contributing to severe health problems like cardiovascular and respiratory diseases and cancers.

PM2.5 can impair blood vessel function and speed up the calcification of arteries and accounts for 4.2 million premature deaths worldwide per year.

Prenatal exposure to particulate matter is associated with low birth weights. Even breathing PM2.5 at relatively low levels can alter the size of a child’s developing brain, which may ultimately lead to an increased risk for cognitive and emotional problems later in life, according to a 2020 Environment International study.

An NIEHS-funded study at the University of Southern California, among the largest studies on the long-term impacts of air pollution on the respiratory health of children, found the following health effects:

• Children who play outdoor sports and live in high ozone communities are more likely to develop asthma.
• Higher air pollution levels increase short-term respiratory infections, increasing school absences.
• Living in communities with higher pollution levels can cause lung damage.
• Children living near busy roads are at increased risk for asthma.
• Children with asthma who were exposed to high levels of air pollutants were more likely to develop bronchitis symptoms.

Wildfires

Natural sources release hazardous substances into the air, including wildfire smoke, volcanic gas and ash, and harmful gases such as methane emitted from anaerobic decomposition regularly occurring in landfills.

Rising temperatures, drought conditions, and insect outbreaks linked to climate change are projected to increase the frequency and intensity of large wildfires.

In a recent year, wildfire smoke exposure caused 6,200 respiratory hospital visits and 1,700 PM2.5-related deaths, costing $16 billion in annual healthcare costs.

While a well-established connection exists between air pollution and respiratory-tract infections, a 2021 study linked wildfire smoke with additional COVID-19 cases and deaths.

Traffic-Related Air Pollution

Traffic-related air pollution emitted from motor vehicles contains most of the components of human-made air pollution: noxious gases (e.g., carbon dioxide, carbon monoxide, nitrogen and sulfur oxides), ground-level ozone, volatile organic compounds, polycyclic aromatic hydrocarbons, and fine particulate matter.

Traffic-related pollution has been linked to a range of adverse health effects, like higher rates of asthma onset and aggravation, cardiovascular disease, and impaired lung function, among others. Additionally, chronic bronchitis is linked to nitrogen oxide as well as particulate matter.

Ozone (Smog)

Ozone (or ground-level smog) is an atmospheric gas created when pollutants are emitted by cars, power plants, industrial boilers, refineries, and other sources that chemically react in sunlight.

When inhaled, smog irritates eyes and airways and increases the risk of developing severe heart and lung conditions. Additionally, smog can exacerbate pre-existing health conditions.

Volatile Organic Compounds (VOCs)

Volatile organic compounds (VOCs), commonly found in cleaning supplies, paints, pesticides, adhesives, and furniture, contain carbon and vaporize at or near room temperature. However, gasoline and natural gas combustion creates a significant source of VOCs.

Occupational exposure to benzene, an industrial chemical component of gasoline, causes leukemia and is associated with non-Hodgkin’s Lymphoma.

VOCs can cause a wide range of health effects — airway irritation, headaches, loss of coordination, nausea, and liver, kidney, or central nervous system damage. The Environmental Protection Agency suggests there are at least 12 VOCs that can be found in tap water that are carcinogenic.

A National Institute of Environmental Health Sciences (NIEHS) study determined that toxic, airborne substances such as methylene chloride — a component in aerosol products and paint removers — are associated with an increased risk of breast cancer.

Polycyclic Aromatic Hydrocarbons (PAHs)

Polycyclic aromatic hydrocarbons (PAHs) contain carbon and hydrogen and naturally occur in crude oil, gasoline, and coal. Because PAHs are also formed by burning these organic materials, several industrial manufacturing and power generation processes produce PAHs as a byproduct. PAHs can also be found in particulate matter.

While there are over 100 PAHs known in the environment, 15 are included in the US Department of Health and Human Service’s 15th Report on Carcinogens.

Allergies

Environmental impacts caused by climate change and botanical sexism are also partly to blame for decreased air quality and longer allergy seasons. Carbon pollution caused by burning fossil fuels has increased global temperatures, which extends warm-weather seasons and stimulates an increase in pollen production. Between 1995 and 2011, warmer temperatures extended pollen seasons by 11–27 days in the US.

In 1949, the USDA Yearbook of Agriculture recommended that only male trees be planted in urban regions instead of “messy” female, fruit-bearing trees, leading to a practice called botanical sexism.

According to horticulturist Thomas Leo Ogren, this practice has led to uncontrollable pollen production and longer-lasting allergy symptoms over the last few decades. Scientists predict that average pollen counts in 2040 will be more than double those in 2000.

Zoonotic Diseases

In the coming decades, climate and land-use changes will put increasing pressure on the migration of numerous species, producing new opportunities for viral spread among previously geographically-isolated species.

These migrating species facilitate zoonotic spillover — a mechanistic link between disease emergence and global environmental changes — by introducing thousands of new opportunities for viruses to jump to/from new species. For example, ticks, a major vector that transmits a greater variety of pathogenic agents than any other blood-feeding arthropod, are expanding their range due to climate change.

According to a 2022 Nature study, climate change drastically increases the risk of new infectious zoonotic diseases transmitted between species from animals to humans. These diseases include zoonotic influenza, malaria, Salmonellosis, West Nile virus, bubonic plague, coronaviruses [severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome], rabies, Lyme disease, Ebola, HIV, and bird flu, among others.

Worldwide, out of around 6,500 mammals (including humans), researchers predict that at least 10,000 virus species are circulating silently in wild mammals that could potentially infect humans. Currently, only 7% of mammals have overlapping habitats and 6% host the same viruses as other mammals.

The same study projects that, among 3,139 mammal species, there could be hundreds of thousands of first encounters between species within the next 50 years even if warming is kept lower than 2°C above preindustrial levels, which could lead to over 4,500 new transmissions.

Even if greenhouse gas emissions are curbed in the coming years, new study models suggest that the increase in viral sharing events may not be completely avoidable. In fact, the study implies that climate change is already driving some transmission events.

Although previous studies have examined how deforestation, extinction, and wildlife trade lead to zoonotic spillover, little research about the influence of climate change on disease transmission has been conducted.

Climate change, human health, and land use are all interconnected. And yet, there has been no large-scale systematic effort to quantify the heat-related human health impacts that have already occurred.

Additional rising healthcare costs can be avoided if humans choose to curb greenhouse gas emissions and adopt more sustainable practices. Wind energy saved thousands of people from premature death between 2007 and 2015, according to a 2017 Lawrence Berkeley National Laboratory study.

Therefore, building more bike paths and sidewalks and transitioning to renewable energy sources could reduce air pollution and boost health. Additionally, folding sustainability into disaster response will help medical providers care for victims of extreme weather events like floods, hurricanes, and wildfires.