Document 2nYXG2rXxQ1V1oRD64dnLExg

MANUFACTURING CHEMISTS ASSOCIATION 1825 CONNECTICUT AVENUE, N.W. WASHINGTON, D. C. 20009 (202) 483-6126 w. s, r. JUL1 7 ^ July 15, 1975 TO: Technical Panel on Vinyl Chloride Research Gentlemen: Enclosed are Mr. A. C. Clark's letter and Dr. J. T. Edsall's reply as they appeared in the July 1975 issue of "Science," Volume 189, No. 4198, pages 174-5. 18, Sincerely, %V Milton Freifeld Project Manager Vinyl Chloride Research MF/etv Enclosure ASI 000014326 t-feT^ERS Vinyl Chloride and DOT: Environmental Effects The report of the AAAS Committee on Scientific Freedom end Responsibility, ab breviated as an article by John T. Edsall (16 May, p. 6K7), requires comment. The section entitled "The case ofdata suppres sion concerning the carcinogenicity of vi nyl chloride" (p. 690) contains omissions and errors that are inconsistent with the committee's concern for scientific freedom and responsibility. Since so much pertinent information has been omitted concerning this matter, readers may be misled into believing the report. Edsall states that, until May 1970, "there had apparently been no researen in the plastics industry concerning the pos sible hazards of vinyl chloride...This is untrue. In fact, the basic published data on vinyl chloride toxicity came from Ameri can industry (/, 2). The information in (2) had been publicly disclosed and presented before their publication dates. Further more, the investigations of Viola and of Maltoni have been supported by European industries. Edsall correctly states that Manufac turing Chemists Association (MCA) mem ber companies entered into an agreement with the European sponsors of Maltoni's work not to reveal preliminary Italian data. The agreement was not dissimilar to those commonly made between American sponsors (government, industry, and aca demic) and research institutions that new data remain the property of the institution and that final results be disclosed through proper scientific channels when a study is completed and evaluated. There was no in tention of withholding adverse data. Under MCA rules, all data developed under its auspices must be promptly reported pub licly. Without exception, this has been done with all data on vinyl chloride. U.S. government scientists knew of Maltoni's preliminary results early in 1973 but considered them to be as preliminary as did U.S. industry. At the Second Inter national Symposium on Cancer Detection and Prevention in Bologna, Italy, 9 to 12 April 1973, Maltoni showed a table of pre liminary results linking vinyl chloride with cancer formation (which was not published until 1974) (J). Umberto Saffiotti, asso ciate director of carcinogenesis at the Na tional Cancer Institute, was present at the meeting and Subsequently discussed the re sults with Maltoni at his Italian laboratory (4). SalTtotti felt that the work should be included in "a well documented report" to be assessed by a review panel of the World Health Organization's International 174 Agency for Research on Cancer (of which the United States is a member). This panel also considered Maltoni's data to be pre liminary at that tune and "decided to post pone compilation of the definitive review to the next meeting of the committee" (/). After a period m which epidemiological and animal studies were being established, MCA, on 17 April 1973, asked the Euro peans to jointly make presentations to U.S. and- European government author ities. The Europeans readily agreed, and on 15 June 1973, MCA called the National Institute for Occupational Safety and Health (NIOSH) and requested an oppor tunity to bring new information to that agency's attention. The appointment was set by NIOSH for 17 July. Five European and American industry representatives presented to NIOSH the information that tumors had been found in animals exposed to vinyl chloride concentrations below those that Viola had reported caused can cer in rats. At that time, no human cancer cases had been reported; therefore, no spe cial significance could be attached to the types of tumors observed by Maltoni. The precautionary label suggested by MCA and referred to by Edsall was illus trated in MCA's Chemical Safety Data Sheet (SD56) on vinyl chloride, revised in April 1972. Section 10.1 on "Health haz ards" refers to Viola's published studies. The Data Sheet states, "Recent research studies reported from Italy indicate that repeated, long-term high level exposures of rats to vinyl chloride monomer vapor can result in the development of malignant tu mors. However, many years of industrial experience with human exposures to con centrations frequently far above current standards have not demonstrated any car cinogenicity to humans." Thus the state ment by Edsall that MCA "... appears to have deliberately deceived NIOSH regard ing the true facts" is inaccurate and mis leading. Albert C. Clark Manufacturing Chemists Association. 1825 Connecticut Avenue, NW, Washington. D.C. 20009 References 1* T R, Torkctson. F Oyen. V, K. Rowe, Am. Ind, H\g. Assoc. J. 22, 354 (1961); R. H. Wilson, W, E. McCormick, C. F. Taium, J. L. Creech, J. Am. Med. Assoc. 201, 577 (1967); E. D. Baretta. R. D. Stewart, J. E. Mutchler, Am. Ind. Hyg. Assoc. J. 30, 537(1969). 2. B. D. Dinman, W A. Cook, W, M. Whitehousc, H, J. Magnuson, T. Ditcheck, Arch. Environ Health 22, 61 (1971); W. A. Cook. P. M. Gicver, B. D, Dinman, H. J. Magnuson. ihid., p. 74; V. N, Dod son, B. D. Dinman, W. M. Whitehouse, A. N. M. Nasr, H. J. Magnuson, ibid, p. 83; G G. Kramer, and J. E. Mutchler, Am. Ind. Hyg. Assoc. J. 33, 19 (1972). 3. C. Maltoni, Excerpta Med. Ini. Congr. See. Ho. 275(1974). p. 4. 4. G. Suffiolii, in U.S. Senate, Committee on Com merce, Subcommittee on Environment, Vinyl Chloride (93rd Congress 2nd session, 1974), pp. 54-56. John T. Edsall errs in crediting DDT with halting a cholera epidemic in Naples during World War II. A National Acad emy of Sciences committee stated in 1970 (/) that "DDT has prevented 500 million deaths due to malaria that would otherwise have been inevitable." However, the Naples miracle involved typhus rather than cholera or malaria. It is unfortunate that Edsall selected an undergraduate student's term paper (2) as "a useful short history of the use of DDT," for several well-informed scientists have written articles and books on DDT which would be more appropriate sources for AAAS articles. He also refers to "the long persistence of DDT in soil," perhaps being unaware that Stringer et al. (3) found the half-life of DDT to be only 3 years in orchard soil after 17 successive years of heavy spraying. Edsall cites DDT's "pro gressive concentration in food chains" as having "led to the killing of great numbers of certain birds and fish"; however, the lack of food chain magnification, espe cially in marine environments, has been pointed out by Moriarty (4), Hamelir.k et al. (J), Harvey (6), and in two committee draft reports of the National Academy of Sciences (7). While Edsall did not recommend halting DDT use for malaria control, some "envi ronmentalists" are again seeking to halt all DDT exports from the United States. It is encouraging to see no such proposals in the AAAS committee report. J. Gordon Edwards Department ofBiological Sciences. San Jose State University. San Jose, California 95192 References 1. Committee on Science and Public Policy, The Life Sciencet (National Academy of Sciences, Wash ington, D C.. 1970), p. 432. 2. G. Mclntire, Environment (St. Louis} 14 (No, 6), 14(1972). 3. A, Stringer, J, A. Pickard, C, H. Lyons, Pestic. Set. 5,5H7(I974), 4. F. Monarty, HewSci 53,594(1972). 5. J. L, Hamclink, R. Wuybrant, R, C, Bull, Trans. Am Fish. Soc 100.207(1971), 6. G. R. Harvey. Oceanus 18, 19 (1974), 1. J. W. Kanwisher, "DDT in the marine environ ment" (chairman's draft of an ad hoc committee report. National Academy of Sciences, Washing ton, D.C., 1971); G. R. Harvey. "DDT in the marine environment-- A review of present under standing" (draft of an ad hoc committee report, National Academy of Sciences, Washington, D.C., 1973). I am glad to note that, as Clark's letter points out. there was research by Ameri can industry on the toxicity of vinyl chlo ride, beginning several years before 1970. In this work, however, what have proved to be the major hazards were not discovered; if they had been, the later story would have been very different. I am obliged also for Clark's correction regarding the pre cautionary label, which did in fact make reference to malignant tumors in rats pro- AS! 000014327 SCIENCE, VOL. 189 duccd by "repealed long-term high level exposures." The altitude expressed in Clark's teller, however, illtisiraies ihe ma jor point that caused concern lo ihe Com mittee on Scientific Freedom and Respon sibility. The extremely ominous Findings in the animal studies did not trigger any ma jor alarm until cases of cancer in factory workers exposed to vinyl chloride began to be reported. This has been in the past the general altitude regarding such problems; I believe that it is now out of date. New re agents introduced into industry on a large scale should be regarded as dangerous un til proved safe. Precautions lo protect workers from inhaling or absorbing them should be built in from the very start, rath er than being superimposed later, after damage has become apparent. Carcino genic substances usually take years to pro duce cancers; we should not wait for the cancers lo appear in human subjects before taking action. Fortunately the. work of Ames et at. (/) and others has shown that carcinogens are generally mutagens. Screening of chemicals for mutageni city can be carried out fairly rapidly. With the techniques available today we can thus often obtain an early warning of danger, but negative results on mutagenicity tests should not be cause for complacency. Highly toxic substances may be nonmutagenic. 1 thank Edwards and others for correct ing the erroneous statement that DDT brought a halt to a cholera epidemic. It was of course a typhus epidemic that was halted by DDT. How this error slipped through I do not know; the error is in any case mine, not that of the committee. This point will be corrected in all reprints. One can add lo the references cited by Edwards a recent review on insecticides by Jukes (2) which contains a vigorous de fense of the value and safety of DDT. Some of the environmental damage that has been charged to DDT was probably unreal or greatly exaggerated; some was probably due to other substances, such as the polychlorinated biphenyls (PCB's), which most analysts long failed to distin guish from DDT and its breakdown pro ducts, Nevertheless the ollicial decision to ban DDT for nearly all uses in the United States was not arbitrary or capricious; it was taken after prolonged hearings, with presentation of a profusion of evidence by both sides. The case for using DDT in countries where malaria is a serious prob lem is far stronger. To my knowledge there is no adequate substitute for the spraying of interior walls of houses with DDT solu tions as an essential element in a malaria control program. I would oppose any poli cy of denying such countries the ability to purchase and use DDT for these purposes. IS JULY I97S The need of the future, however, is lo de velop less persistent .uni more specilic |H:xIicicles that can he directed against a nar row range of targ' i species, while doing little or no damage i<> others. John T. Edsai.i. biological Laboratories, Harvard University, Cambridge, Massachusetts 02138 References 1. B. Ames, F. D. Lee. W. h. Durston, Proc. Nad. Set. USA 70,782(1973). 2. T. Jukes, Naturwisstnschajten61,6(1974). Copied by MCA for Milton Freifeld 7/15/75 AS I 000014328