Louisville was named the second worst in its region for ozone pollution in the American Lung Association’s 2025 “State of the Air” report.
According to the report, Louisville received an “F,” ranking the 29th worst across the nation with more than eight unhealthy days per year regarding ozone pollution. This can cause asthma attacks, sickness for those who work outdoors and low birth weight in babies, according to the American Lung Association.
How Did Louisville Get This Ranking?
Louisville has high amounts of nitrogen oxides (NOx) and volatile organic compounds (VOCs), which can form a new gaseous pollutant, ozone. The following are reasons why Louisville has high amounts of NOx and VOCs:
- Louisville has high levels of emissions resulting from combustion from vehicles and industries.
- Since Louisville is part of the Ohio River Valley, the air tends to be stagnant.
- Louisville frequently has an air and weather pattern that brings other regions’ air into our area. In recent years, this brought wildfire pollution into the area from locations like Canada.
- Louisville receives high amounts of sunlight, especially in the summer. This is needed for NOx and VOCs to form ozone, thus leading to high levels of this pollutant.
What Are the Consequences of Ozone Pollution?
Ozone can be highly reactive. Louisville has highly reactive ozone that can interact with humans by making them unhealthy from the immediate exposure or from being exposed over a long period of time. Ozone can also damage plants, including crops, along with other parts of the environment.
People who are exposed to ozone pollution have a higher risk of developing lung problems. For example, ozone pollution can trigger asthma attacks or cause asthma to develop, especially in children. People who have chronic obstructive pulmonary disease or other conditions that affect breathing can have worsened symptoms because of ozone pollution.
Also, ozone pollution can change your heart rhythm, causing atrial fibrillation or heart rate variability. These conditions could potentially trigger a heart attack or put you at risk for heart disease.
Ozone can impact the whole body. Long-term exposure to any ozone pollution—even low amounts of it—can lead to the following conditions:
- Heart disease
- Stroke
- Diabetes
- Autism in unborn babies
- Alzheimer’s disease
Louisville’s ozone pollution tends to affect some areas more than others because there are pockets of higher pollution. These pockets are in parts of the West, South and East Louisville.
Can I Help Decrease Ozone Pollution?
The main way to decrease ozone pollution is to reduce emissions. You can reduce emissions by:
- Carpooling
- Turning your car off instead of idling
- Bicycling or walking if possible
You can also support policies that make public transportation easier or more available and support electric transportation or solar energy policies that reduce combustion.
Planting trees is another way to decrease the impact of ozone pollution. Trees can change where NOx and VOCs are in the environments, and they also reduce urban temperatures and create shade. As a result, trees can reduce the impact of ozone on health.
Can I Offset or Prevent Damage from Ozone Pollution?
Some people wonder if supplements or certain foods can offset damage from ozone pollution, but this isn’t proven at this time. The best step to take is to talk to your primary care provider before taking any supplement or adding a food to your diet. And the best way to protect yourself is to prevent being around ozone.
You can monitor the amount of ozone pollution each day and choose to stay indoors if the air quality is bad. IQAir has a Louisville air quality map you can monitor.
University of Louisville and UofL Health Are Here to Help
The Christina Lee Brown Envirome Institute at University of Louisville engages researchers and citizen scientists to learn how our natural, social and personal environments impact health. With Louisville as an urban laboratory, researchers partner with community members and policy makers to discover how to build healthier cities. To learn more, call 502-852-5873.
If you are having trouble breathing or feel like you are not getting enough oxygen when breathing, call UofL Physicians – Primary Care at 502-588-4343 to make an appointment with a primary care provider, or visit your nearest UofL Health – Urgent Care Plus location. In an emergency, dial 911.
UofL Physicians – Cardiology and UofL Physicians – Cardiology Associates offer a Preventative Cardiology Program that is focused on preventing heart and vascular disease before a patient has a cardiac event and preventing existing cardiovascular disease from getting worse. Call 502-588-7010 today to schedule a consultation.
