Millions of People in Arizona Urged To Avoid Driving To Help Air Quality

Phoenix residents have been urged to refrain from driving if possible amid an Ozone High Pollution Advisory issued by the Arizona Department of Environmental Quality (ADEQ) on Tuesday.

According to a webpage for the ADEQ, ozone was expected to cause the air quality index (AQI) to peak at 104 on Tuesday, which falls within the “unhealthy for sensitive groups” category. The forecast anticipates air quality to be at its worst from around 1 p.m. to 6 p.m. local time.

To avoid contributing to worsening ozone levels, an alert issued by the National Weather Service (NWS) shared the ADEQ’s message and asked Phoenix-metro area residents—more than 5 million people, according to census data—to refrain from driving or using gas-powered equipment during the advisory.

The NWS broadcast the Ozone High Pollution Advisory in an alert issued on Tuesday morning.

“This means that forecast weather conditions combined with existing ozone levels are expected to result in local maximum eight-hour ozone concentrations that pose a health risk,” the NWS alert said. “Adverse health effects increase as air quality deteriorates.”

The worsening air quality is driven by ozone levels, an air contaminant that can “cause breathing difficulties for children, older adults, as well as persons with respiratory problems.”

In addition to protecting oneself by limiting physical activity, residents also are asked to avoid driving, if possible.

“You are urged to car pool, telecommute or use mass transit,” the NWS alert said. “The use of gasoline-powered equipment should be reduced or done late in the day.”

Despite the suggestion, drivers face no penalties if they choose to drive amid the air quality alert.

Phoenix is among the worst U.S. cities for air pollution, Cronkite News reported. According to a 2022 report by the American Lung Association cited in the article, Phoenix ranked as the fifth-most ozone-polluted city in the U.S.

ADEQ air-quality meteorologist Matt Pace told Newsweek that Phoenix receives 95 percent or more sunshine throughout the year, which contributes to ozone formation. High pressure is often present over the city, creating hot temperatures, which leads to high concentrations of ozone as well. He added that wildfire smoke from California and the Pacific Northwest can worsen air quality.

A stagnant atmosphere is contributing to the worsening ozone this week, Pace said. An Ozone High Pollution Advisory will remain in place on Tuesday and Wednesday. It will likely be reduced to an Ozone High Pollution Watch for Thursday and Friday, with air quality improving by the weekend.

On high pollution advisory days, Pace suggested residents make “small, incremental changes” to their daily lives to limit emissions, such as carpooling, using public transportation and refueling their vehicles after dark or avoiding long drive-through lanes.

ADEQ issues its five-day forecast daily, meaning residents can plan to telecommute to work on days when ozone is expected to be highest.