Good Up High but Bad Nearby: The Facts on Ground-level Ozone

You may have remembered learning about ozone in elementary school. Ozone is a odorless and clear gas made up of 3 oxygen atoms. Ozone gas makes up an entire layer in our atmosphere, where it protects our Earth from harmful UV rays. A few years ago, scientists and citizens grew concerned about an emerging hole in the ozone layer. Recent studies show that our ozone layer is repairable and that the hole in our ozone layer is closing year by year.

Ozone can also form closer to the ground. Ground-level ozone is created through a chemical reaction between nitrogen oxides (NOx) and volatile organic compounds (VOCs).  NOx and VOCs are released by cars, power plants, refineries, and other industrial sources. When heated by sunlight, ground-level ozone is created. This is why ground-level ozone levels can get especially high during warm, sunny days.

This graphic depicts the formation of ozone from car and factory emissions

What are the health effects of ozone?

Ozone is harmful to both humans and the environment. Exposure to ground-level ozone can create many respiratory problems in all individuals, including wheezing, cough, chest pain, throat and nose irritation, and inflammation. Long-term exposure to ozone can actually scar lung tissue and damage your lungs. Children are especially vulnerable to high ground-level ozone because they are lower to the ground, breathe more air per pound, and their lungs are still developing.

Ozone can also negatively affect the health of active adults, the elderly, and those with immune-compromised diseases and asthma.

Take action to protect your health on high ozone days.

There are several actions you can take to protect your and your loved one’s health during days where ground-level ozone is high.

  • Staying indoors and avoiding high-exertion activities are recommended.
  • Carpool with friends and family members if you are running errands or getting places.
  • For children with asthma, make sure asthma controller medication is nearby or taken before going outside.
  • Avoid burning wood fires or burning trash.
  • Conserve electricity and avoid doing yard work with gasoline-fueled tools.