Arizona air pollution has decreased by 62 percent in all emissions over the past 40 years, according to the Arizona Department of Environmental Quality (ADEQ).
This report comes after a record low last summer when the Environmental Protection Agency (EPA) said Southern Arizona had the worst air quality report since 2012.
“We do have our occasional bad days which seem to sometimes overshadow our progress,” said Arizona Air Quality Division Director Timothy Franquist.
The drastic air quality drop last summer was due to the EPA revising the primary and secondary ozone standard levels to make health standards more protective of public health.
“The revised standards are what makes us closer to violating the EPA health standard for ground-level ozone than ever before,” said Beth Gorman, the senior program manager for the Pima County Department of Environmental Quality.
Ozone is created by a mixture of air emissions and causes a variety of health problems. Effects are particularly sensitive for children and the elderly says the EPA. People with respiratory and heart diseases are also at higher risk.
Elevated ozone levels can cause: chest pain, coughing, throat and airway inflammation, harm lung tissue and worsen bronchitis and emphysema, the EPA has said. Ozone is not only harmful to human health but also to ecosystems and vegetation.
Arizona has a large variation in air quality throughout the state.
“Air quality in Arizona ranges from very clean environment to one of the worst due to large differences in our city development and land use” said Avelino F. Arellano Jr, professor of Data Assimilation and Atmospheric Chemistry at the Department of Hydrology and Atmospheric Sciences at the University of Arizona.
Flagstaff has relatively clean air due to less metropolitan traffic compared to Phoenix where there are high levels of emissions from mass daily metropolitan activity.
“In the warmer months is when we start to see ozone creep in. This is a function of the longer days, and when we start to see the ozone become a problem” said Franquist.
The decrease in air emissions exists even after Arizona has experienced continued population growth and miles traveled over the past four years.
A major factor to the decrease, officials said, Officials how motor vehicles have gotten cleaner over the years.
“But if we do violate the EPA health standard, there may be economic impacts to our community associated with having to change the type of gasoline we use or possibly impacts to businesses if new regulatory requirements are implemented” said Gorman.
Megan Gibbs is a reporter for Arizona Sonora News, a service from the School of Journalism at the University of Arizona. Reach her at megangibbs@email.arizona.edu