Virginia has adopted stricter guidelines that have expanded the list of waterways and fish considered to be contaminated by a chemical linked to cancer, including more stretches of the Roanoke, New and James rivers.

The revised guidelines for acceptable PCB levels in fish will put many popular catches off the menu, or recommended for a twice-a-month maximum.

The state issued 27 new PCB advisories and modified 11 old advisories in response to increasing concern about risk from longtime consumption of PCB-tainted fish.

The new consumption advisories include 37 more miles of the Roanoke River from Niagara Dam to Lafayette in Montgomery County. They mean sought-after species in that stretch, such as largemouth bass, should be eaten no more than twice a month or not at all by pregnant or nursing women. Portions of Tinker and Peters creeks are included in the new advisory.

The level of PCBs has not increased in Virginia waters, but the state decided to mirror the tougher standards adopted in Maryland and North Carolina, said Khizar Wasti, director of the Division of Health Hazards Control with the Virginia Health Department.

The state has also recalculated the risk of PCB exposure based on the new assumption that some people eat fish taken from the same water source for as long as 30 years. The previous assumption had been a maximum of nine to 12 years from one source.

The new restrictions cover nine more fish species in the upper section of the Roanoke River and downstream in Smith Mountain Lake. In the lake, the state's 2003 advisory against eating flathead catfish 32 inches or larger remains, but flatheads smaller than that should be eaten sparingly, too, according to the new advisories.

In the New River below Claytor Lake Dam, carp still should not be eaten, an advisory first issued in 2001. But the state added two species of catfish to the advisory. On parts of the New River above the dam to the Interstate 77 bridge at Jackson Ferry, carp and smallmouth bass should be eaten no more than twice a month.

In the James River from Big Island to Richmond, gizzard shad, carp, flathead catfish and two other species should be limited to two meals a month. It was the first time warnings about PCB contamination in fish were issued for the upper James River.

PCBs, or polychlorinated biphenyls, labeled a probable carcinogen by federal environmental officials, are oily, synthetic chemicals once used to insulate transformers and other electrical equipment. The manufacturing of PCBs was stopped in the United States in 1977, but the chemicals persist in mud and soil for decades.

Bottom-feeding fish and predators are most likely to accumulate the chemicals in affected waters.

Virginia has steadily lowered the acceptable levels of PCBs in fish. Prior to 1980, Virginia followed guidelines developed by the U.S. Food and Drug Administration that considered PCB levels higher than 5,000 parts per billion dangerous. The FDA lowered the levels to 2,000 ppb in 1984.

Virginia lowered its level to 600 ppb in 1998. The new guidelines released Monday recommend fish with 50 to 500 ppb of PCBs be eaten no more than twice a month, and those with 500 ppb or more should be avoided altogether.

Tips for reducing the risk include:

• Eat smaller fish, because they are younger and have not accumulated as many PCBs in their fatty tissues.

• Eat fish from various watersheds, because PCB levels vary by location.

• Discard the skin and fatty flesh, because PCBs are concentrated there.

• Broil, bake or grill the fish, because deep-frying seals the chemicals into the meat.

Despite the warnings, health officials urged a common-sense approach to eating native fish.

"As long as they don't eat it 12 months a year, every day, it should pose little harm to them," Wasti said.

The Associated Press

contributed to this report.

On the Net:

Virginia Department of Health:

www.vdh.state.va.us/