Air quality in the Valley is the worst it's been in nearly five years at a time when the federal government is looking to toughen standards and crack down on states that fail to meet them.
The upshot is this: Our health is at risk. We're breathing ozone that kills the cells in our lungs. And, with ozone levels already elevated, it will be more difficult for the state, and Maricopa County in particular, to meet air quality standards, officials say.
In recent weeks, county monitoring stations have measured ozone levels not seen in nearly five years, according to the Arizona Department of Environmental Quality.
"There have only been 21 days since 2000 that have had equal or greater concentrations," an air quality report from last week stated.
Nobody points to direct consequences for noncompliance where ozone is concerned, but the Maricopa County region is already threatened with losing billions in federal transportation dollars because it's failed to keep another pollutant - dust - in check. Cities, towns, businesses and government groups have worked together to create a multi-year plan to address the dust in the air. If the state can get through this year without a violation, it will finally be in compliance for particulate matter, otherwise known as dust.
But ozone is a separate issue.
A tougher standard for ozone would be "a good thing for anybody that breathes. It protects our health and ensures our health marker is set at a good level," said Holly Ward, spokeswoman for the Maricopa County Air Quality Department. "The challenge ... is looking to see where we reduce those pollution sources. You kind of need to see where the new standard is going to be to see what our approach will be and to know how much we need to tighten our belts if you will."
Ground-level ozone is the main component in smog. It is created by a chemical reaction when nitrogen oxides and volatile organic compounds - which are both emitted by natural products as well as by motor vehicle exhausts and gasoline vapors, industrial emissions and chemical solvents - are heated by the sun. When temperatures start to rise, Arizona enters "ozone season," typically April through September.
"When you have those two in the air and you have a lot of sunlight and the right kind of temperatures, an O2 becomes an O3 (ozone) if you will. It's complex. It's not completely understood," said Eric Massey, director of the air quality division of ADEQ.
What is known is that high ozone levels may send asthmatics to emergency rooms and damage even healthy lung tissue, said Christian Stumpf, regional director of advocacy for the Arizona Lung Association.
"It's a constant battle we're facing year after year. There's ways we can all work to improve the situation such as the things you hear a lot about: carpooling, using mass transit, trying to conserve energy," Stumpf said. "Getting ozone in your lungs, we kind of compare it to getting sunburn on your skin. It kills the cells in the lungs. It's affecting everyone."
The federal Environmental Protection Agency maintains standard health levels for ozone, as well as other air pollutants. Maricopa County's ozone levels have exceeded federal health standards seven times this year, including Monday. Rising levels this week prompted ADEQ to issue an ozone high pollution advisory for Wednesday, encouraging residents to limit driving and stay indoors.
Last year, the county's ozone levels rose above federal standards on 10 days.
Every five years, the EPA reviews health standards of the various pollutants. Currently, the 8-hour primary standard for ozone is 0.0775 parts per million volume air concentration. That means a monitor's measurements are averaged over an 8-hour time frame.
The new standard could be set between 0.060 and 0.070 parts per million, according to the EPA website. A final ruling is expected by the end of July.
ADEQ's Massey said the new standard could be an issue because ozone may exist in some areas that don't even have high vehicle use. The ozone occurs there due to wind patterns or the combination of naturally made gases and sunlight.
Add man-made components from vehicle combustion and industry and there could be more troublesome days ahead.
"The biggest contributor by an individual here in the Valley are single occupant vehicles," said Maricopa County's Ward.
That's why the county is working with Valley Metro to encourage public transportation, van pools, car pools and telecommuting. And that's why Arizona has its vehicle emissions program.
Not only do the millions of vehicles on Arizona's roads contribute to the ozone level, but it's believed Arizona's neighbor to the west, California, is also impacting the air we breathe.
Air quality leaders know ozone - as well as the gases that create it - can be transported with wind patterns. Many states on the East Coast have "transport commissions," in fact, that explore this issue, Massey said.
It's believed the winds from the west that come into Arizona prior to the monsoon may contribute to factors that lead to poor air quality.
The state has been noncompliant in the past with EPA ozone levels, but made improvements, said Collene McKaughan, associate director of the air division for EPA in Region 9, which includes Arizona. When the new standard is set, all states will be told how they measure up. If they're noncompliant, they'll have time to come up with and implement a plan of action to improve the air. That could take several years, McKaughan said.
The American Lung Association recently gave Maricopa County an F in its State of the Air report.
But Stumpf said the county is working to address the issues.
"We know Maricopa County is making really, really strong strides to improve on all their rankings, whether ozone or PM (particulate matter) standards. We'd like to think of this as not a grade on effort. They have made some good headway," Stumpf said. "From the lung association, as we talk about everything air quality-related, we like to say that this has to be a total team and total public effort to make the air quality better within the Valley. That's really what we want people to recognize and take away."