New warnings on eating some catches from the Columbia River have been issued by the Washington state Department of Health.
For all of the Columbia River, the recommended limit from eating lamprey, a culturally important food for tribes, is now no more than four meals per month for adults.
Some vulnerable populations — children and women pregnant or nursing — should eat no more than two meals per month.
The Department of Health's concern is the PCB and mercury levels found in tissue of lamprey as shown by data of the Columbia River Inter-Tribal Fish Commission.
PCBs were used as coolants and lubricants in electrical equipment until their manufacture was stopped in the United States in 1977, but PCBs remain in the environment and can be taken up by fish.
Lampreys are a jawless fish, older than dinosaurs, that look like their distant relative, the eel, according to the Washington state Department of Fish and Wildlife.
They migrate downstream to the ocean and then latch onto a host species such as salmon or rockfish to feed on their blood.
The other change announced Thursday was for sturgeon caught in the Columbia River downstream from the Bonneville Dam.
The Oregon Health Authority joined in the advisory on limits to sturgeon eaten due to the PCBs in their tissue.
The Oregon and Washington agencies say adults should eat no more than six meals a month. Children and women pregnant or nursing should eat no more than four meals a month.
Eating large amounts of fish contaminated with PCBs and mercury can cause negative health effects over time and can lead to potential learning and behavioral problems, according to the Washington state Department of Health.
PCBs can be passed onto babies during pregnancy and nursing. Babies and young children are most vulnerable to health problems from PCBs and mercury.
The state of Washington has other fish advisories that remain unchanged, including a warning not to eat northern pikeminnow caught anywhere in the state and not to eat more than two meals per month of largemouth and smallmouth bass.