8.1: Issues in Environmental Health

The environment in which people live directly shapes their health, affecting both individuals and communities. Healthy living conditions can lead to positive health outcomes, while unhealthy environments increase the risk of chronic diseases and health hazards, ultimately shortening life expectancy.  When the environmental determinants of health (covered in section 1.3) are compromised, the entire population's well-being suffers. These threats may arise naturally or from human activity and social factors.

Focusing on environmental determinants of health improvements offers a dual benefit: better direct public health outcomes and an indirect gain through increased productivity and a higher quality of life (Pan American Health Organization, n.d.). The burden of environmental health on population health is significant, contributing to 12 million deaths and illnesses globally due to diseases that arise from how people live or work in unhealthy environments. It causes exacerbating diseases like respiratory, cardiovascular, and infectious diseases, and increases the risk of injuries and mental health problems. This burden is unequally distributed, disproportionately affecting vulnerable populations such as low-income communities, children, the elderly, and those with pre-existing conditions, through factors like air and water pollution, climate events, limited access to healthy food, exposure to toxic by-products from industry and agriculture, and unsafe living conditions (Prüss-Ustün et al., 2016).  The 9-minute video below explains how pollution affects health in people worldwide and should be seen as a crisis to all of us.  

Pollution: a global public health crisis

Pollution: a global public health crisis

This video from The Lancet explains how pollution affects the health of communities worldwide. 

 

Pollution in the United States

Again, as in the communicable disease section, although environmental health has a major impact on the global population, we will focus specifically on its impact on the United States population. The three biggest environmental problems today are climate change, biodiversity loss, and pollution, which are interconnected crises that threaten public health, the stability of the United States, and the planet, for that matter. The main contributors to climate change are the burning of fossil fuels and deforestation (which increase gases such as carbon dioxide in the atmosphere), which cause the warming of the planet, leading to rising sea levels and extreme temperatures. Human activities cause widespread habitat destruction and ecosystem alteration, leading to species extinction and declines in wildlife populations, which in turn impact food security and livelihoods. Air pollution includes emissions from industry and vehicles; water pollution includes industrial and agricultural runoff; and there is a global crisis of plastic waste. Because most plastics are never recycled, this harms human health, contaminates natural resources, and causes irreversible damage to the environment (Kimber, 2025). 

The 2025 U.S. pollution trend shows a worsening overall picture, with climate change-driven events such as extreme heat, drought, and wildfires leading to increased levels of both ozone and particulate pollution. Nearly half of all Americans (156.1 million people) live in areas with failing grades for unhealthy ozone or particle pollution, according to the "State of the Air" 2025 report, despite decades of successful efforts to cut air pollution sources. The report also shows that 85 million people across 115 counties in the United States are breathing air with unhealthy levels of particle pollution that violate the annual air quality standard, year-round.

In addition, based on 2021-2023 data, 77.2 million people lived in counties experiencing unhealthy spikes in particle pollution. This represents a 12.1 million increase over the previous year and marks the seventh consecutive year that health threats from this pollutant have risen (The Medical Society Consortium on Climate & Health, 2025). 

Air Pollution

As explained above, air pollution is the biggest problem to public health, and one of the biggest culprits is carbon dioxide. Carbon dioxide is a powerful greenhouse gas; its concentration has increased significantly due to human activities such as burning fossil fuels, deforestation, and agricultural practices. An excessive amount of atmospheric carbon dioxide drives global warming, raising the Earth's average temperature. The U.S. Energy Information Administration (EIA) forecasts a 1.8% increase in energy-related carbon dioxide emissions in 2025 (US Energy Information Administration, 2025).  Another major pollutant is particulate matter, also known as soot. Particulate matter consists of very small airborne particles that are introduced in the air through the combustion of gasoline, oil, diesel fuel, burning of wood, and dust from construction sites, landfills, agriculture, wildfires, industry, and wind-blown (California Air Resources Board, 2025). 

Carbon dioxide and particulate matter are tied together both at the source and through climate impacts. The burning of fossil fuels is a common source, simultaneously emitting both carbon dioxide and particulate matter that degrade air quality. Furthermore, climate change driven by elevated carbon dioxide levels increases events such as wildfires and intense dust storms, which are major sources of airborne particulates. Exposure to these particles is harmful to the heart and lungs. Particle pollution is linked to serious health problems, including premature death (especially in vulnerable populations), cardiovascular events like heart attacks and irregular heartbeats, and a variety of respiratory issues such as worsened asthma, reduced lung function, and symptoms like coughing and difficulty breathing (Environmental Protection Agency, 2025; California Air Resources Board, 2025). 

The United States is second (only surpassed by China) in carbon dioxide emissions (Central Intelligence Agency, n.d.). In 2023, about 66 million tons were emitted (Environmental Protection Agency, 2025). Under the Clean Air Act of 1963 (amended many times since its inception), the Environmental Protection Agency is required to set and periodically review national air quality standards for six key ambient pollutants: carbon monoxide, lead, nitrogen oxides, ozone, particulate matter, and sulfur dioxide. This ongoing process ensures that the standards remain adequate to protect both public health and the environment, necessitating updates as needed (Environmental Protection Agency, 2024; Wikipedia, n.d.). 

Audio news recording from NPR: Air pollution (Borunda, 2025). Transcription is available on the NPR website.

Public Health Approach to Environmental Health

Now that we understand the impact the environment has on population health, we will discuss approaches public health uses to address these issues. The focus will be on the measures public health examines to develop programs and policies that improve environmental health for everyone. The concept of environmental justice is important here. Environmental justice is the principle that everyone—regardless of their community—has the right to live and thrive in a safe, healthy environment, to benefit from equal environmental protections, and to have a meaningful say in the decisions that affect them.  From this concept, a movement rooted in the civil rights movement, environmentalism, and community mobilization, called the environmental justice movement, emerged. It has been noted that marginalized communities face a higher, unfair burden of environmental threats, including exposure to lead, air pollution, hazardous waste, and extreme heat. These exposures are directly linked to damaging health issues such as cancer, asthma and other respiratory illnesses, cardiovascular problems, and neurological and developmental disabilities (American Public Health Association, n.d.)

 

 

Reference

American Public Health Association. (n.d.). Environmental Justice. APHA www.apha.org

Borunda, A. (2025). Air pollution still plagues nearly half of Americans. That does a number on our health. NPR www.npr.org

California Air Resources Board. (2025). Inhalable particulate matter and health (PM2.5 and PM10). CAARB ww2.arb.ca.gov

Central Intelligence Agency. (n.d.).  The World FactBook: Country comparisons -carbon dioxide emissions. CIA www.cia.gov

Environmental Protection Agency. (2024). NAAQS review analysis. EPA www.epa.gov

Environmental Protection Agency. (2025). Air quality - National summary. EPA www.epa.gov

Environmental Protection Agency. (2025). Health and environmental effects of particulate matter (PM). EPA www.epa.gov

Kimber, R. (2025). The biggest environmental issues we face today. EarthB www.earthyb.com

The Medical Society Consortium on Climate & Health. (2025). State of the air 2025. The Medical Society Consortium on Climate & Health. www.medsocietiesforclimatehealth.org 

Pan American Health Organization. (n.d.).  Environmental Determinants of Health.  PAHO www.paho.org

Prüss-Ustün, A., Wolf, J., Corvalán, C., Bos, R., & Neira, M. (2016). Preventing Disease Through Healthy Environments: A Global Assessment of the Burden of Disease from Environmental Risks. WHO https://iris.who.int/server/api/core...7db110/content

US Energy Information Administration. (2025). Short-term energy outlook. EIA www.eia.gov

Wikipedia. (n.d.). Clean Air Act (United States). Wikipedia www.en.wikipedia.org