It's a lot like last year.

According to one measure, two of the state's top 10 polluters and five of the top 20 are in the New River and Roanoke valleys and the Alleghany Highlands. Last year, there were four in the top 20.

Alleghany, Giles and Montgomery counties were among the 10 Virginia jurisdictions with the highest reported toxic chemical release totals -- as they were last year.

The Toxics Release Inventory, mandated by federal law and compiled by the Virginia Department of Environmental Quality, tracks the release, transfer and management of more than 650 chemicals and chemical categories. The federal government has decided the chemicals on that list cause cancer or other acute health problems or harm the environment because of their toxicity and persistence.

In the latest TRI, which covers 2004, 477 Virginia facilities reported using or releasing 197 of those chemicals. They released about 28,559 tons of them into the air and water. Another 2,806 tons were spread on soil, contained in ponds, put in landfills or otherwise put into the land.

The inventory does not include chemicals from most non-manufacturing facilities, plants with fewer than 10 employees, facilities that use less than the trigger amount of chemicals in a year -- in most cases 500 pounds -- many non-industrial sources or emissions from planes, trains and automobiles.

The TRI is a bulk measure that doesn't take into account the relative health threats posed by different chemicals, though it does segregate persistent bioaccumulative toxic chemicals from the rest. Persistent bioaccumulative toxic chemicals -- such as lead and mercury -- remain in the environment for a long time, accumulate in body tissue and are not easily destroyed.

The Alliant Ammunition and Powder Plant outside Radford handled more TRI chemicals than any other facility in Virginia. It was sixth on the state list of chemicals released -- more than 3 million pounds. Last year it was fourth.

MeadWestvaco in Covington was second again with nearly 4.5 million pounds.

Cinergy Solutions of Narrows was 13th -- up from 34th -- with nearly 1.5 million pounds.

Georgia-Pacific's Big Island mill was 18th, releasing more than 1 million pounds. Last year it was 22nd.

AEP's Glen Lyn power plant was 20th -- down from 16th -- releasing 781,641 pounds of chemicals on the list.

The chemicals they're releasing range from acetaldehyde to zinc. Their health effects range from watery eyes to cancer.

Last year, an Associated Press analysis of air emissions of TRI chemicals using 2002 data showed Pulaski County, Montgomery County and Radford had health risks many times the national median. DEQ officials told supervisors in Montgomery and Pulaski's town council the analysis was flawed. The chemical releases recorded in the TRI pose no health threat, they said.

Last month, DEQ officials provided Montgomery County supervisors with documents that said, in part, "The majority of the health risk is concentrated in the top 5 percent most polluted neighborhoods, where the risk score is at least 19.5 times the national average."

Montgomery County scored more than 17 times above the national median. Radford was 25 times the median. Pulaski was more than 48 times the median.

During talks with local officials and in the latest TRI report, the DEQ pointed out that the inventory is based on estimates, not measures, and so should not be compared from year to year or taken as completely accurate -- though the agency says the figures show an 11.56 percent decline in the release of toxic chemicals statewide over that past three years.

The Environmental Integrity Project, founded by an EPA official who resigned in protest over what he considered lax enforcement of environmental regulations, produced a report in 2004 that claimed the TRI underestimates toxic chemical releases by about 16 percent.

At that time, that would have translated to more than 330 million pounds per year nationwide.