More than halfway through the ozone season, Pima County Department of Environmental Quality’s (PDEQ) air quality monitors indicate there has been only one exceedance of the ground-level ozone standard so far this summer. By this time last year there were seven days when ozone exceeded the EPA health standard. In 2018, the region had enough ozone exceedance days to violate the standard. A violation of air quality standards could lead to EPA designating eastern Pima County as a non-attainment area and increasing regulations for some local and new businesses.
“There are many factors that contribute to the creation of ground-level ozone. I would like to think the decrease in the number of unhealthy air days this year was partially due to the community hearing our message and taking actions to reduce the emissions that cause ozone,” said Beth Gorman, Senior Program Manager for PDEQ’s Clean Air Program. “Any day we can drive fewer miles, conserve electricity, reduce the minutes we spend idling our engines, and refuel in the evening, will be a day that many in our community can breathe easier,” said Gorman.
Ground-level ozone is created when emissions from a variety of sources, including motor vehicles, industries, power plants, gasoline fumes, paint and solvents, as well as certain types of vegetation, react in sunlight. This differs from the naturally-formed ozone layer that is about 6 miles above the surface of the Earth and protects us from intense solar radiation.
Ozone targets the respiratory tract and can cause a reduction in lung function, aggravation of respiratory diseases (such as asthma), and increased hospital and emergency department visits. Symptoms of exposure may include itchy eyes, nose and throat; coughing; difficulty breathing; and chest pain. Individuals most at risk include people with lung disease, children (because their lungs are still developing), older adults, and people who are working or exercising outside.
To know when ozone is elevated, PDEQ monitors ozone at eight different monitoring sites throughout eastern Pima County and provides real-time air quality data at
https://bit.ly/2jVk9ZC. Five-day air quality forecasts, provided by Arizona Department of Environmental Quality, are available at
https://azdeq.gov/tucson/forecast.