With elevated levels of PCBs still present in some fish species, state health officials are continuing to advise against eating blue catfish, channel catfish and smallmouth buffalo caught in Lake Worth.
Texas Department of State Health Services testing showed elevated levels of polychlorinated biphenyls, or PCBs, along with the insecticides Aldrin and dieldrin in those species of fish when samples were collected in 2008.
But the newest warning lifted advisories against consuming largemouth bass, common carp, freshwater drum and white crappie. It replaces a 2000 warning against consuming all species of fish in Lake Worth.
"It will get better with time as long there aren't more pollutants introduced into the watershed," said Department of Health Services spokesman Chris Van Deusen.
Used as coolants and lubricants in electrical transformers and capacitors, PCBs were banned in 1979 but there was no requirement to replace devices that used them. PCBs degrade slowly in the environment and can cause cancer as well as immune system, reproductive, developmental and liver problems if consumed over a long period.
Aldrin and dieldrin can cause cancer, birth defects and kidney damage in humans. The insecticides were restricted by the EPA in 1974 and banned in 1987, but remain in the environment for years.
There is no health risk from these contaminants for people swimming or boating in Lake Worth.
In July, state health officials issued a similar advisory against consuming all species of fish from the Clear Fork and West Fork of the Trinity River below the Lake Worth dam and the Benbrook Lake dam down the main stream of the Trinity to the Freestone-Anderson County line. That advisory was due to elevated PCBs and dioxins found in fish samples.
Bill Hanna, 817-390-7698