Shelby County residents can breathe a little easier, but are still facing dangerous amounts of ozone pollution, according to a recent American Lung Association study.

The county’s short-term particle pollution grade improved from a D to a C from 2009-2010, according to the Lung Association’s 2010 “State of the Air” report.

However, the county’s ozone pollution retained an F rating throughout both years. The American Lung Association based its 2010 State of the Air report on data it collected in Shelby County from 2006-2008.

Shelby County is included in the Birmingham-Hoover-Cullman metropolitan area, which had the fifth-worst short-term and seventh-worst year-round particle pollution out of all U.S. cities, according to the report.

Both particle pollution rankings were shortly behind large cities like Phoenix, Los Angeles and Pittsburgh.

The Birmingham metro area was also the 19th-worst ozone-polluted city in the country, according to the study.

But one factor could be negatively impacting the air quality grades in Shelby County, according to Shelby County Environmental Services Manager Robert Kelley.

According to an air quality monitoring site map on the Alabama Partners for Clean Air website, Shelby County’s only air quality monitoring station is in Helena. Jefferson County contains 10 monitoring stations.

“If I’m not mistaken, there’s only one monitoring station in Shelby County, and it’s on the (Jefferson-Shelby county) line,” Kelley said. “We don’t have anything down here (in southern Shelby County) to monitor it.”

Shelby County officials also issue a no-burn ordinance every year from May 1- Nov. 1, which helps cut down on the amount of ozone pollution released in the county, Kelley said.

In 2006-2007 Shelby County experienced 38 orange ozone alert days and three red ozone alert days. The county also experienced five orange alert days for short-term particle pollution days during the same time period.

According to the Environmental Protection Agency, orange ozone alerts affect children, elderly residents and those with respiratory problems. Red ozone alerts affect everyone involved in outdoor activities.

Orange particle pollution alerts affect those with heart and lung disease, older adults and children.

“Breathing ozone irritates your lungs, leaving them with something like a bad sunburn, and can cause health problems the day you breathe it in, and even the days after,” read a Lung Association press release. “Ozone can cause wheezing, coughing, asthma attacks and can even shorten your life.”