Ground-Level Ozone: What to Know & How to Stay Safe

Ground-level ozone forms when volatile organic compounds (VOCs) and nitrogen oxides (NOx) from sources like vehicle exhaust and industrial emissions react in the presence of sunlight and heat. This reaction produces ozone, which can cause respiratory problems, aggravate asthma, and reduce lung function, particularly in vulnerable populations.

I thought Ozone was Good? There are two types of ozone, stratospheric (good ozone) and ground-level (bad ozone). Her are the key differences:

  • Stratospheric Ozone - Good ozone is located in the stratosphere, which is 10-30 miles above the earth’s surface. It acts as a protective layer that shields the earth from the sun’s powerful ultraviolet (UV) radiation. The stratospheric ozone layer is essential for maintaining life on earth as it protects all living things from the harmful effects of excessive UV radiation. 
  • Ground-level Ozone - Bad ozone is located near or at the earth’s surface, the troposphere, which is the lowest layer of the atmosphere (where humans live!). Ground-level ozone is particularly common on sunny, warm days when pollutants from emissions react in sunlight and cause health concerns. An Ozone Action Day is declared when weather conditions are conducive to the formation of ground-level ozone at unhealthy levels.

What’s the Health Risk of Ground-level Ozone? Ground-level ozone can have significant impacts on all people, but particularly those part of sensitive groups such as children, the elderly, and people with health issues like asthma in the following ways:

  • Respiratory Problems: Ozone can irritate the respiratory system, leading to inflammation of the airways and reduced lung function. This can exacerbate asthma symptoms, causing wheezing, coughing, and shortness of breath. Children and elderly individuals with asthma are particularly vulnerable to these effects. This can also lead to increased susceptibility to respiratory infections and other respiratory illnesses.
  • Aggravation of Chronic Conditions: Individuals with chronic respiratory conditions such as chronic obstructive pulmonary disease (COPD) may experience worsened symptoms and increased frequency of flare-ups when exposed to elevated levels of ozone.
  • Cardiovascular Effects: Ozone exposure has also been linked to cardiovascular effects such as increased heart rate, blood pressure changes, and inflammation of the heart and blood vessels, which can be particularly concerning for elderly individuals or those with cardiovascular diseases.
  • Impacts on Children: Children are more susceptible to the effects of ozone because their respiratory systems are still developing. Exposure to ozone during childhood can impair lung function development and increase the likelihood of developing respiratory problems later in life.

How to Stay Safe 

  1. Check Air Quality Alerts: Stay informed about local air quality conditions with the JustAir app, government agencies, and other reliable sources. Residents can sign up for air quality text alerts for specific monitors to know when air quality from wildfire smoke is spreading close to home. 
  2. Reduce Emissions: Carpool, use public transportation, or combine errands to reduce vehicle emissions. Avoid using tools like lawn mowers and reduce electricity use during peak hours.
  3. Limit Outdoor Activities: Minimize outdoor activities, especially strenuous exercise, during peak ozone hours (usually midday to late afternoon).

Advocating for Long-Term Change

  1. Education and Outreach: Educate neighbors about the health impacts of ground-level ozone and empower them to take action to reduce emissions and improve air quality.
  2. Support Clean Air Policies: Advocate for stricter emissions standards for vehicles and industrial sources, as well as policies that promote renewable energy and energy efficiency.
  3. Promote Sustainable Transportation: Support investments in public transit, biking infrastructure, and walkable communities to reduce vehicle emissions.
  4. Engage with Local Government: Participate in local planning processes and advocate for policies that prioritize air quality and climate resilience.

By raising awareness, advocating for policies that reduce emissions, and promoting sustainable practices, individuals and communities can work towards preventing ozone action days and mitigating the impacts of climate change on air quality.

Want more information? Visit the Environmental Protection Agency’s resource, Ground-level Ozone Basics

Darren Riley
June 25, 2024
Subscribe to our newsletter!

Sign up for our newsletter to get all the Just Air updates, information, and news.