COEUR d'ALENE - There will be a new effort in the coming year to find and reduce sources of Polychlorinated Biphenyls, or PCBs, that are entering the Spokane River system.

But what are PCBs?

The Agency for Toxic Substances and Disease Registry describes PCBs as a mixture of individual chemicals which are no longer produced in the United States, but are still found in the environment.

Health effects that have been associated with exposure to PCBs include acne-like skin conditions in adults and neurobehavioral and immunological changes in children.

PCBs are known to cause cancer in animals, and they are likely to cause cancer in humans, according to the ATSDR.

PCBs have been used as coolants and lubricants in transformers, capacitors and other electrical equipment because they don't burn easily and are good insulators. The manufacture of PCBs was stopped in the U.S. in 1977 because of evidence they collect in the environment and can adversely affect health. They were completely banned in 1979.

Regulatory agencies are still finding them prevalent in the environment. The cause for concern in the Spokane River is the high level of PCBs in the flesh of fish on the Spokane side of the river, but not in the fish on the Idaho portion of the river.

Tom Eaton, with the EPA, said he has learned recently that PCBs are still showing up in all sorts of products that are manufactured today.

During the Spokane River Forum held last week in Coeur d'Alene, Eaton said the city of Spokane recently tested a number of products for PCBs and found that hydro-seeding materials contain an alarmingly high amount of PCBs.

"That is something we expect not only the city of Spokane to act on, but other cities and hydro-seed users within the watershed to act on," Eaton said, adding EPA would expect them to devise a way to reduce the amount of PCB in that product or remove it from the watershed.

According to ATSDR the most commonly observed health effects in people exposed to large amounts of PCBs are skin conditions such as acne and rashes.

Studies in exposed workers have shown changes in blood and urine that may indicate liver damage.

ATSDR said PCB exposures in the general population are not likely to result in skin and liver effects. Most of the studies of health effects of PCBs in the general population examined children of mothers who were exposed to PCBs.

Women who were exposed to relatively high levels of PCBs in the workplace or ate large amounts of fish contaminated with PCBs had babies that weighed slightly less than babies from women who did not have these exposures.

Babies born to women who ate PCB-contaminated fish also showed abnormal responses in tests of infant behavior. Some of these behaviors, such as problems with motor skills and a decrease in short-term memory, lasted for several years.

Tests exist to measure levels of PCBs in blood, body fat, and breast milk, but these are not routinely conducted, according to ATSDR. Most people normally have low levels of PCBs in their body because nearly everyone has been environmentally exposed to PCBs.

The tests can show if PCB levels are elevated, which would indicate past exposure to above-normal levels of PCBs, but cannot determine when or how long someone was exposed or whether they will develop health effects.