Millions Told To Avoid Driving As Health Warning Issued
Cars pictured in Glendale, Arizona on March 12, 2020. Residents have been warned to limit driving because of air quality concerns.
Millions of people in Arizona have been warned to limit driving amid concerns about air quality.
An Ozone High Pollution Advisory has been issued for Maricopa County, including the Phoenix metropolitan area, on Friday by the Arizona Department of Environmental Quality (ADEQ).
The area, which includes Phoenix and surrounding cities like Mesa, Scottsdale, and Tempe, has a population of around 4.9 million people as of the 2020 census.
People residing in this area are "urged to car pool, telecommute or use mass transit," according to advice from the National Weather Service (NWS).
The advisory has been issued as ozone levels are expected to reach levels that pose a health risk for sensitive groups, the agency said.
Ozone levels will reach moderate levels by 11am, according to ADEQ's website. Between 1pm and 4pm they will reach levels that are unhealthy for sensitive groups.
Similar levels are projected for Saturday, and on Sunday and Monday they are predicted to be even higher.
Newsweek reached out to The Arizona Department of Environmental Quality for more information via email outside of regular working hours.
At ground level, ozone is a harmful pollutant. High ozone levels typically occur on hot, sunny days, as ground-level ozone forms when pollutants emitted by vehicles, industrial facilities, and other sources react in the presence of sunlight. It is a major component of smog.
High levels of ozone can cause breathing difficulties for children, older adults, and people with respiratory problems, per the NWS.
Exposure to ozone can also make people more susceptible to a lung infection, aggravated lung diseases or an increased frequency of asthma attacks.
People in the affected area are also advised to decrease physical activity and to limit the use of gasoline-powered equipment or do it late in the day, according to the agency.
Using cars and gas-powered equipment contributes to the formation of ozone because this emits nitrogen oxides and volatile organic compounds.
Air quality varies throughout the day, so those in vulnerable groups are advised to check the current air quality in their area when planning outdoor activities by visiting the website AirNow.gov.
"Ozone is complex and arises from many sources. Hot summer weather is definitely a contributor in that it sets up the conditions for ozone formation," Steven Brown, program leader for the Chemical Science Laboratory's Tropospheric Chemistry program, which is part of the National Oceanic and Atmospheric Administration, previously told Newsweek.
The latest warning comes after several similar ones were issued across the country.
Start your unlimited Newsweek trial