How do experts grade East Valley air? An F

Mike Branom, Tribune

April 30, 2008 - 7:12PM

Traffic travels along U.S. 60 as the Superstition Mountains are obscured by dirty air in Mesa Wednesday.

Thomas Boggan, Tribune

Imagine your lungs going about their business: Oxygen in, carbon dioxide out.

Now take a deep breath of the Valley's air, laden with ozone. The inside of your lungs, once pink and healthy, react as your skin does with a bad sunburn.

Your breath grows short and you wheeze. There's a cough, and when you follow with a deep inhalation your chest feels like it is being stabbed with invisible knives.

The Valley is the 19th-most ozone-polluted metro area in America, according to an American Lung Association study released today. Sadly, this is an improvement: Last year's State of the Air report ranked the Phoenix-Mesa-Scottsdale area at No. 15.

In 2004-06, the Valley experienced an average of eight days annually in which the ozone level reached unhealthy levels. Three days a year or more will earn a city a grade of F, the study's authors said.

Pinal County received a D, as well.

Ozone is created in the atmosphere when nitrogen oxides (NOx) and volatile organic compounds (VOCs), also called hydrocarbons, come into contact with both sunlight and heat both of which the Valley has in spades.

And from where do NOx and VOCs come? From gas-powered vehicles. We have plenty of those, too.

As for particulates, such as soot, dust and aerosols, the news is better but getting worse. The Valley does not rank in the top 25, or even the top 100, of particulate-polluted areas.

However, the American Lung Association's grade is a D, and the number of days with unhealthy particle pollution is on the rise.

Above the rest of Arizona, the skies are clear. Five counties, including Coconino, Pima, and Pinal, received A grades for their lack of particulate pollution, while As for ozone were earned by Cochise and Yuma counties.