Here to stay…Poison, Caution, Beware

Most of us have heard of PCBs, but how many actually know what they are? PCB stands for polychlorinated biphenyls. Now, who knows what those are?

Polychlorinated biphenyls are man-made toxic chemical substances that belong to a large chemical family known as chlorinated hydrocarbons. So, now we know that PCBs are man-made toxic chemicals.

But why did man make them?

Since 1929, PCBs have been commercially manufactured for a variety of uses. Because of their great resistance to chemical and biological breakdown, they were used as hydraulic fluids in electrical equipment such as transformers, capacitors and hydraulic systems as well as being used in paints, adhesives pesticides, sealants and plastics. I say were used because the production of PCBs has been banned or limited throughout the world. This came about in the 1970s when PCBs were found we in fish from polluted waterways, in wildlife, and in human organs, blood, fatty tissue and milk. But even after the ban on manufacturing PCBs, they remain a threat because of the very reason they were thought to be so important -- their resistance to breakdown.

PCBs remain in the environment for long periods of time, accumulating in sediments, soils, plants, fish, birds and mammals. PCBs tend to become more concentrated (they build up) as they move up the food chain from the organism to humans who are at the end of that chain.

Why not clean up the areas where PCBs are found? It's, not that simple because PCBs are mostly a non-point source contaminate which means they are found everywhere. However, some clean-up efforts are being made where there is a definite source of contamination such as plant discharges.

PCBs are a major concern because of their potential harm to humans. It's been proven PCBs cause skin lesions, eye and liver problems and may cause cancer and birth defects.

Since PCBs are found in all parts of the environment -- the air, water, sediments, etc., and may enter the human body through the lungs, gastrointestinal tract and skin, more than half the population of the United States have some PCBs in their bodies.

Fish, however, appear to be a more significant source of PCBs as they accumulate and magnify in the aquatic food chain. Let's say, for instance, that PCBs leaked from transformers, capacitors, etc. and settled in the ground. Since PCBs are not soluble, they are bound to sediment and may be washed into water systems. Bugs eat the sediment and, the bugs, in turn, are eaten by fish where PCBs accumulate in the fatty tissue. Then, along comes man who catches and eats the fish.

The U.S. Food and Drug Administration (USDA) set limits at 2.0 parts per million PCBs (two parts of PCBs per million parts of fish tissue) that can be found in fish and fish products that are sold in the United States. This means that any fish resting higher than 2.0 parts per million are considered contaminated, or "hot" as biologists call it. Once a fish sample is listed as "hot," it must then test under the 2.0 parts per million limit for two consecutive years before it will be taken off the contamination listing.

A fish consumption advisory was jointly issued in February, 1990 by the Kentucky departments for Health Services, Fish and Wildlife Resources and Environmental Protection. This advisory warned of the potential health risk from PCBs found in channel catfish, carp, and white bass caught in the Ohio River. The advisory was renewed on March 15, 1991, after the agencies reviewed the 1990 fish contamination information from the Ohio River Valley Water Sanitation Commission (ORSANCO). ORSANCO more than doubled the number of samples submitted for analysis due to increased public and agency concerns. Fish were collected from a variety of locations on the Ohio River and its tributaries. The results indicated the levels of PCBs in carp and channel catfish collected at some locations continue to be above the USDA's contamination level. Other species that showed low levels of PCBs were sauger, white crappie, drum, smallmouth buffalo and paddlefish (paddlefish are "hot" with chlordane - another story). Even though these species registered low· levels of PCBs, frequent consumption may increase the risk of long-term adverse health effects.

Advisories have also been issued for all fish caught in Mud River and Town Branch located in Logan, Butler, and Muhlenberg counties; all fish caught in Drakes Creek from the dam on West Fork at Franklin, Kentucky downstream to confluence with Barren River; and all fish in the length of Little Bayou Creek located in McCracken County. All advisories are listed in Kentucky's fishing digest.

Immediate health effects from eating PCB-contaminated fish have not been documented, but because of the persistence of PCBs, they accumulate in living systems, causing concern over their long term effect.

If you decide to eat fish taken from the contaminated waters, here are some pare suggested by the health and protection agencies to reduce the risk of harmful effects:

~Women of childbearing age should not eat the listed fish.
~Properly cleaning, skinning, trimming and cooking the fish can minimize the intake of PCBs.
~Eat only skinless and boneless fillets with as much fat removed as possible.
~Eggs (or roe) should be discarded.
~Roasting or baking reduce levels of PCBs more than frying or microwaving. Cooking does not destroy PCBs, nor does it lower their toxicity.
~None of the juices or fats that cook out of the fish should be eaten.
~Advisories are issued not as a ban on fish consumption, but to allow the public to avoid the potential health risk.

Fish from the areas listed will continue to be monitored.

I asked fishery biologist, Doug Henley, what other rivers in the commonwealth have contaminated fish. Various species from several rivers have been tested and are being tested. To date, according to Doug, fish from the Licking River and the Kentucky River haven't shown any PCBs, while levels below the "hot" limit were found in species in the Cumberland River (below Barkley Dam), Salt River and Tennessee River(below Kentucky Dam). No fish consumption advisories, however, have been issued on fish species taken from these waters.

Now that we know the what, why and where of PCBs, will we learn from it? Or will we sit back and wait for wildlife species to give us more warning signals on what we're not only doing to them, but to ourselves?