The Menace of PCB

The Menance of PCB Environmentalists were confident that they had ferreted out the nation's major pollutants after they put the finger on substances like DDT, mercury, lead and phosphates. Now an important newcomer has cropped up in the form of polychlorinated biphenyls (PCBs), colorless, odorless, syrupy chemicals that are manufactured in the U.S. under the trade name Aroclor by the Monsanto Co. Until recently, PCBs were used in industry in many ways, for instance as softeners in plastics, paints and rubber, as additives in printing inks and papers. Although they are now used primarily as agents in heat exchangers, there is growing evidence that alarming quantities of PCBs have found their way into living organisms and that they pose a potent new threat to the environment.

Two years ago. New York Democratic Congressman William F. Ryan was told by a constituent about the dangers of PCB. Checking further. Ryan found studies showing that large amounts of PCBs had been discovered in the fish and sea birds of several countries. The studies also revealed that the compounds can cause liver damage in mice and disrupt the calcium metabolism of birds, which then lay thin-shelled eggs. Alarmed by the findings, Ryan delivered a House speech on PCBs. The Department of Agriculture responded by halting the use of PCBs--but only in pesticides. Then, despite complaints from customers, Monsanto announced that, as of September 1970, it would stop sales of PCBs except for "absolutely essential" use in electrical equipment.

Polluted Poultry. To the public, however, PCB was still largely unknown --until the disclosure, in December 1970, that Campbell Soup had found high PCB levels in some New York State chickens destined for its products. Once notified, the New York and federal departments of agriculture stopped poultry shipments from the three counties supplying Campbell and ordered the burial of 146,000 contaminated birds. Where did the PCB come from? Officials speculated that it had been transmitted by chicken feed made from stale bakery goods that had been wrapped in PCB-coated plastic bags.

One of the worst instances of PCB pollution occurred last spring. A North Carolina poultry raiser, worried over the low hatching rate of his chickens, ran independent tests and found that the fatty tissue of the birds contained up to 40 p.p.m. of PCBs (the federal limit for poultry is 5 p.p.m.). The contamination was traced to a Wilmington, N.C., fish-meal plant where PCBs were leaking from a pipe in a heating system into the meal. Officials were dismayed to learn that the leak had gone undiscovered for nearly two months and that 13,000 tons of tainted feed had been sent to 64 customers in twelve Southern and Midwestern states.

Ryan was furious. "The Federal Government's actions are inexcusable," he said. "This entire incident could have been prevented if the Department of Agriculture and the Food and Drug Administration had lived up to their responsibilities to protect the public." He then introduced legislation that would totally ban PCBs from interstate commerce.

Official Goof. Still, evidence of PCB pollution continued to crop up, probably because markets were already saturated with PCB products. In mid-August, FDA disclosed that it had seized more than 75,000 fresh eggs from wholesalers in Norfolk, Va., because the chickens that laid them had eaten feed containing the tainted fish meal. Though the agency assured the public that no tainted feod would leak out, it later admitted an official goof: a shipment of 60,000 eggs had somehow got through federal inspectors and, presumably, into the stomachs of Washington, D.C., residents.

Two weeks ago, the Department of Agriculture announced that "unacceptable levels of the poison PCB" had been found in turkeys processed by a Minnesota subsidiary of Swift & Co. About 50,000 birds were voluntarily withheld from the market while agriculture experts searched for the source of the contamination. Around the same time. Michigan Governor William Milliken ordered a halt to the commercial sale of coho salmon after PCB was found in salmon taken from Lake Michigan. Last week FDA disclosed that PCBs had also been found in several different kinds of dried foods, including baby cereals and shredded wheat. The PCB source has been traced to the cardboard packaging material, which was made partly of recycled PCB-treated copying paper.

PCBs are difficult to cope with for a number of reasons, first of all because the chemicals are hard to identify. They so closely resemble DDT they can be differentiated only by spectrographic analysis. PCBs are long-lived and, like DDT, their potency is multiplied as they work their way up the food chain. Unlike DDT, however, these chemicals are not sprayed but get into the environment accidentally, which makes them even harder to trace and control.

For all the grim warning signs, there is as yet no proof that PCBs at present low levels are harmful to humans. Most scientists, and critics like Congressman Ryan, however, feel that the safest course is to treat PCBs just as though they were the most potent of pollutants, until tests determine exactly what the long-term effects may be.

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