Document mpvevgvGkMpmxyGrYZg93DkMB

Editor: Cathy Cooper Circulation Director: Shirley Galant Managing Editor: Ron Grandon Assistant Director: Iris M. Schwartz Assistant Editor: Cheryl Russell Marketing Director: Sharon Wills Associate Editors: Raymond Galant, Production Manager: Dorothy Hill Steven Goldschmidt, Natalie Pargas, Assistant Managers: Alice Wilkes, Madonna Leaf Sonia Rothschild Publisher: Louis Rothschild, Jr. NEGATIVE HEALTH EFFECTS FOR PCB TESTS NOTED, BUT RETURNS STILL OUT A panoply of negative results in scientific studies of polychlorinated biphenyls was paraded before the EPA-sponsored PCB seminar May 12-13 (See May 12, Page 7). But the results were countered with statements pointing out the difficulty of finding positive results, and one statement appeared to gain consensus backing:' "One would truly want an internationally-approved, well-designed experiment for both sexes of animals for the animals' lifetimes." The statement was made by Dr. Seymour Friess of the consulting firm of Drill, Friess, Hays, Loomis and Shaffer, Arlington, Va., who was immediately asked: "Which of the 209 isomers are to be tested?" Dr. Renate Kimbrough of the Centers for Disease Control sarid the suggestion was "great," but, "We don't live in an ideal world." She continued: "Should we take, note of these (positive) animal studies and try to prevent exposure, or should we wait until we can sort; out the death certificates? Our (government workers) responsibi ity is for protection of health." Friess noted, "One way of protecting, is to reduce exposure to the lowest possible level." ' .1 . . Dr. William Gaffev. manager of epidemiology for Monsanto, tola the conference that the 10 epidemiologic studies since 1978 of the human health effects of PCBs, one involving more than 2,500 workers, have found nothing more than "dermatitis" and mild liver function abnormalities. They failed to find a link between disease and populations which are exposed other than occupationally, he said, adding: "All studies agreed that there was no relationship between reported illnesses and symptoms and PCB exposure. The three mortality studies all disagreed on the cancers for which marked excesses were found. The one study reporting a (non-significant) excess of liver cancer showed no relationship of the excess to duration or latency of exposure." I . Disagreement over the significance of a 1975 National Cancer Institute study linking PCBs to cancer was noted during the seminar. Dr. Robert. James of the consulting firm of Ecology and Environment, Buffalo, N.Y., said chronic tests "have produced few, sporadic positive results." He added: "To consider only the positive tests, recognizing the possibility of false positives, species variations and the more numerous contradictory findings, would preclude an objective scientific evaluation of the information about PCBs." | . He pointed out that "science relies on the reproducibility of thie test and the general species applicability of the responses," and concluded: PESTICIDE & TOXIC CHEMICAL NEWS (ISSN 014S0501) is published weekly for $250 per year and $170 for addi tional subscriptions by Food Chemical News, Inc., 1101 Pennsylvania Ave., S.E., Washington, D.C. 20003. Secondclass postage paid at Washington, D.C. 20013. POSTMASTER: Send address changes to the above address. PCB-ARCH-EXT0378582 ;3 ' li^Pag Ma) 11 V \ CHI it "re T 17) l off ider PCI :hei tha dsic the tick Ins tras rt, AS D re^ ir. (S. P> as st TS tic te sun by new Pa i not 5ur { N nmui F. table li; lize B ilth i ourci P g Tf H< n c th t un Cc t b FI an F in< I h 1 Pqge 4 May 19, 1982 PESTICIDE & TOXIC CHEMICAL NEWS "Considering the lower and declining environmental exposure -to PCBs, it seems unlikely that we will ever find an environmental exposure to humans which will produce injury. Therefore, the risk of environmental exposure to PCBs is considered to be insignificant." Dr. Kimbrough noted, however, that in the 1975 study, 26 out of 154 animals developed liver lesions referred to as nodular hyperplasias, and, "There were a lot of other areas where cells looked normal but were arranged differently and would stain differently." ' She noted there is "still argument" as to whether the nodular hyperplasias will develop into neoplasms, but, "Some people are saying that if these hyperplasias develop, you don't need to do a two-year study because you will have carcinoma." A review of the study by researchers at Johns Hopkins University, she said, found additional tumors in the study animals. She also noted that mice and rats, used in most studies, appear to be among the least sensitive species to PCBs, with more sensitivity shown by monkeys. - Speaking from- the audience, Dr. Muriel Lippman of ERNACO, Inc., noted the difficulty of finding cancer in insensitive tests, stating that in a group of 25 animals, nine would have to show lesions to give a 90% chance of detecting a cancer, compared to no lesions in 25 control animals. NEW CROP GROUPINGS FOR MINOR USE TOLERANCES PROPOSED ,, _ i EPA May 13 proposed expanding its crop groupings under ljs0.34 for tests on the amount of residue remaining in order to ease the establishment of minor use tolerances for pesticide residues. The proposal, the agency said, would "provide for reguIatory| relief by reducing the amount of daia that must be generated by industry" and would "reduce the paperwork burden on industry and EPA by reducing the number of petitions for tolerance." Commen' t on the proposal may be submitted until July 12 (See May 5^, Page 2). ' . . j However, EPA said "all group tolerances currently in effectj will remain unchanged" in order "to avoid adverse impacts on affected parties and to 'achieve a systematic change over from the existing groups to the proposed groups." The agency explained: ' I "Retroactive implementation of this new crop grouping scheme could create tolerances for crops not currently included in [existing 180.34(f) groups, and revoke tolerances for crops included in tne existing. . . , groups but not in the proposed groups, x x x These jexisting group ' tolerances will remain in effect for those crops included in the crop groups definitions prior to publication of this notice. | These existing ' group tolerances will be changed to group tolerances under the proposed groupings, when finalized, as part of the agency's tolerance reassessment phase of the Registration Standards Program." EPA said it "has not chosen to develop formulas to be used in extrapolating data from one crop to another, since the crop grouping concept leads to an estimate of the maxim" level of residue that could occur on any crop within the group." It added that "there is no estimation of residue levels on individual crops within the group." PCB-ARCH-EXT0378583