Toxic compounds called PCBs have been found in largemouth bass in the North Carolina portion of Lake Wylie, N.C. health authorities said Friday in warning the public to limit consumption of the fish.
South Carolina authorities, at the same time, issued advisories for PCB-contaminated largemouth bass caught in the S.C. portion of Lake Wylie and in the Catawba River downstream.
Largemouth bass are likely to be contaminated by mercury, a toxic metal. An N.C. advisory is already in effect for that contaminant, which was the subject of a federal crackdown this week.
Friday's advisory follows warnings for local lakes that were issued last January. Then, for the first time, health officials warned the public not to eat fish - channel catfish - from Mountain Island Lake west of Charlotte. Mountain Island is the major water supply for Charlotte and Gastonia, N.C., although the PCBs found there pose no risk to drinking water.
Those results prompted further fish tests of the N.C. lakes, said state toxicologist Kenneth Rudo.
The tests confirmed PCB contamination of bass in the Mecklenburg and Gaston County parts of Lake Wylie, Rudo said. They also indicated that more testing needs to be done of Mountain Island Lake, where results from blue catfish were inconclusive.
But the additional testing gave a clean bill of health to another heavily fished reservoir, Lake Norman.
"We did a lot of (fish) sampling and didn't find any fish with levels that exceed the PCB limit," Rudo said.
In addition to largemouth bass, a variety of species including channel catfish, spotted bass and white perch were tested, he said. Both PCBs and mercury are widespread contaminants of fish in U.S. waters.
Polychlorinated biphenyls, known as PCBs, are chemicals used to insulate and lubricate a wide array of products, from electrical transformers to paint. The United States banned their use in 1979.
Ingested PCBs can hurt neurological development of children, the reproductive and immune systems, and may cause cancer.
Mercury is a naturally occurring element that is typically released into the environment from industrial smokestacks. The Environmental Protection Agency on Wednesday issued rules that are designed to capture 90 percent of mercury from coal-fired power plants, their major source of releases.
Unborn babies and young children exposed to high levels of mercury can suffer life-long learning and problem-solving issues.
Friday's advisory, from the N.C. Division of Public Health, warns women who are pregnant, nursing or of childbearing age, and children under 15, not to eat largemouth bass caught in Lake Wylie. Other people should eat no more than two meals a month of those fish.
The similar advisories issued in January for Mountain Island Lake, the S.C. portion of Lake Wylie and the Catawba River below Wylie are still in effect.