There's something in the air -- and it is not good. The Augusta-Aiken area had the fourth worst air quality in the nation Friday, according to the government air quality Web site, Airnow.gov.

"It is just staggering to me to be fourth on that list," said John Brice, a pulmonologist and the chief of medicine at the Augusta Department of Veterans Affairs Medical Centers. This comes on the heels of the American Lung Association ranking Augusta 21st on its list of worst air quality because of fine particulate matter. The Airnow ranking is for both high particulate and high ozone content. That was expected to ease somewhat today.

Particulate matter in the air is a complex problem, said Susan Zimmer-Dauphinee, the manager of the ambient air monitoring program for the Georgia Environmental Protection Division. The state tracks 52 types of fine particles, some of which come directly from sources such as coal-fired power plants and vehicle exhaust or forest fires, she said.

"So that complicates our lives when there are so many different sources that they come from," Ms. Zimmer-Dauphinee said.

While technically the area is still in compliance with federal standards, the state began noticing higher levels and has begun talking to Augusta and Aiken officials about what could be done to bring those levels down, said Jimmy Johnston, the planning program manager for Georgia's EPD. Together with the South Carolina Department of Health and Environmental Control and the U.S. Environmental Protection Agency, they have been meeting with an ad hoc local group called the CSRA Air Quality Alliance about what could be done voluntarily. That could include burning bans, requiring cleaner diesel engines or fuels, or promoting telecommuting and carpooling, Mr. Johnston said.

"There are many, many sources to the problem," he said. "Some of those you have no control over; some of it is naturally occurring. But the vast majority, you have control over."

The group has been meeting since February 2007 to explore their options, said Paul DeCamp, the planning director for the Augusta-Richmond County Planning Commission, which is helping to coordinate the effort. They hope to have a plan together by the end of the year, he said.

Georgia officials at least would like to see those efforts pick up more steam, Mr. Johnston said.

"They've been working hard, but it's been pretty slow," he said. "The progress that they've been making has been slower than some other areas that we've been working with."

The air quality is an "ongoing concern," Mr. DeCamp said. "Our main concern is public health."

The particulate pollution is a main concern to advocates, said June Deen, the vice president of public affairs for the American Lung Association's Southeast Region.

"It is the most dangerous of all of the pollutants," she said. "And to some degree, it is the one we are least aware."

Particulate pollution can harm those with lung problems and put at risk those with heart disease and diabetes, she said. There is even some evidence of increased risk of lung cancer, Ms. Deen said.

Patients ask whether wearing a mask would help, but that probably won't cut it, Dr. Brice said.

"Honestly, the standard masks, the surgical mask, dust masks that you can get from Home Depot or Lowe's are not going to really filter out the stuff we're talking about," he said. "Ozone, which is one component, is a gas, and so it will go straight through that mask. The particles we're concerned with are those that are less than 2.5 microns." Thousands would fit on the head of a pin.

Some high-grade masks could filter some particles, but they are too uncomfortable to be a reasonable solution, Dr. Brice said.

The main recommendation is to check air forecasts and avoid going out if you have respiratory problems, he said.