Courtesy of MCC
If asked to offer their unfiltered reactions to the word “ozone,” many people might not hesitate to say, “It’s bad.” But ozone is more complex than that and can actually be good.
Ozone is a gas composed of three atoms of oxygen that occurs in both the upper atmosphere of the Earth and at ground level. Where ozone is found determines if it’s good or bad. Ozone in the upper atmosphere, often referred to as “stratospheric ozone,” occurs naturally.
According to the Environmental Protection Agency, this ozone is considered good because it protects humans from harmful ultraviolet rays produced by the sun. While stratospheric ozone can protect humans, ground-level ozone offers no such protection, acting instead as a harmful air pollutant.
How is ground-level ozone formed?
Ground-level ozone, also known as tropospheric ozone, is created by chemical reactions between oxides of nitrogen and volatile organic compounds. These reactions result when pollutants emitted by various sources, including cars, power plants and refineries, are exposed to sunlight. The EPA notes that ground-level ozone is most likely to reach unhealthy levels on hot, sunny days in urban environments. However, ozone levels can still be unhealthy in winter, and rural areas are not immune, as wind can transport ground-level ozone from cities to the countryside.
What are the harmful effects of ozone?
Ozone can cause a number of health problems that affect the respiratory system. While more extensive studies are necessary, the EPA notes that existing studies suggest that long-term exposure to ozone may increase the risk of death from respiratory causes. Some of the respiratory issues that can develop as a result of ozone exposure include:
- Difficulty breathing deeply and vigorously
- Shortness of breath and pain when taking deep breaths
- Inflamed, damaged airways
- Greater frequency of asthma attacks
- Chronic obstructive pulmonary disease
Even healthy people are susceptible to these effects, which can be more serious in people with existing respiratory conditions and diseases, including asthma.
Because their lungs are still developing, children are at the greatest risk of exposure to ozone. Kids also tend to spend more time outdoors than adults when ozone levels are high, increasing their vulnerability to ozone-related health issues. Older adults and people who work outdoors also are most at risk of breathing ozone-contaminated air.
Ozone is not a dirty word, though a certain type of ozone can compromise human health. Learn more at epa.gov