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J v; Mtf'-v r c LETTERS ' lie M f' 1 7-C t( ) /l/C irti-d- Agency for Research on Cancer (of which the United Si.lies is a member). This panel John'T. Edsall errs in crediting DDT with halting a.qholcra epidemic in Naples Vinyl Chloride and DDT: Knvimiiitcntal Kflccts The report oT the AAAS Committee on aUo eon-nitered Maltoni's data to be preliir.m.irs al that time and "decided to post pone compilation of the definitive review :-lo ihe nc\i meeting of the committee" (4). during World War HI. A N .11 ion al Acad emy of Sciences.committee stated lit 1970 (I) that "DDT has prevented 500 million deaths due to malaria that would otherwise Scientific i'reediun and Responsibility, ab After j period in which epidemiological breviated as an article by John T. EcK.ill and .inmi.il sindie-. were being established. (16 May. p. 6S7). requires comment. The." MCA. on I~ April 1973. asked the Euro have been inevitable." However, the Naples miracle involved typhus rather than cholera or malaria. section entitled "The case of data suppres'i' peans ; > i !.-.!% make presentations to It is unfortunate that Edsall selected an sion concerning the carcinogenicity of vi U N and I i.r.ipean government author undergraduate student's term paper (3) as nyl chloride" (p. 690) contains omissions ities Ire I .I Teans readily agreed, and "a useful short history of the use of DDT," and errors that are inconsistent with the on I' 1 1 '' ; MCA called the National . for several well-informed scientists have committee's concern for scientific freedom and responsibility. Since so much pertinent information has been omitted concerning this matter, readers may be misled into Ins;c..,.. t C.upational Safety and Meal... sit sfli .,nd requested an oppor tune. ' n- new information to that ager.. . i -n The appointment was written articles and books on DDT which would be more appropriate sources for A'AAS articles. He also refers to "the long persistence of DDT in soil." perhaps being believing the report. Edsall states that., until May 1970. 'There had apparently been no research in se: ` : N li m >. r 17 July. Five European and \ ,-Justcy representatives pre .. -.. j "s: i iw H the information that unaware that Stringer el al. (3) found the half-life of DDT to be only 3 years in orchard soil after !7 successive years of the plastics industry concerning the pos lurnsir s.-ia.) .r.-and in animals exposed heavy spraying. Edsall cites DDT's "pro- sible hazards of vinyl chloride... .'"This is -to (e concentrations below , gressive concentration in food chains" as untrue. In fact, the basic published data on (Hose ; V.. .. ha' f reporfed^caused cart.|' s^havtjjg "led to .he killing of great numbers vinyl chloride toxicity came from Ameri hc"e-Ccirr V v -~,jr-x ynre.-rno. -,b: nijian cancer .of. certain birds and fish": however, the can industry (/. 2). The information in (?) `Cases h.;j '-.c-j ryponadt.'Chetefore. no spe lack of food chain magnification, espe had been publicly disclosed and presented -c}i.a4l-'ss.-.i.'emti.up.r-'coilld he attached to the cially in marine environments, has been before their publication dates. Further types ut tumors observed by Maltoni. pointed out by Moriarty (4). Hamelink et more. the investigations of Viola and of The preje'.K>na'fy label suggested by,. al..(5), Harvey (6), and in two committee Maltotii have been supported by European MCA and rererred to by Edsall was illus draft reports of the National Academy of industries. trated in MCA s Chemical Safety Data Sciences (7). Edsall correctly states that Manufac Sheet (SD5M on sinyl chloride, revised in While Edsall did not recommend halting turing Chemists Association (MCA) mem-. April 1973 Section 10.1 on "Health haz DDT use for malaria control, some "envi ber companies entered into an agreement ards" refers to Viola's published studies. ronmentalists" a.e again seeking to halt all with the European sponsors oTMaltonrs bThe Data Sheet states. "Recent research DOT exports from the United States. It is work not to reveal preliminary Italian studies reported from Italy indicate that encouraging to see no such proposals in the data. The agreement was not dissimilar to repeated, long-term high level exposures of AAAS committee report, those commonly made between American' `.ratS'Vd vinyl chloride monomer vapor cant,s , , J. Gordon Edwards sponsors (government, industry, and, acai result in the development of malignant iu- Department ofBwlsgical Sciences, demic) and research institutions that new rnors, Howeser. ,many years of industrial: SanJose-State.yhniversily-.j-. .... . data remain the property of the institution experience with human exposures',$o curi-1 *San Jo^e,'California 95i9'i>t . . and that final result; be disciosed through proper scientific channels when a study is. completed and evaluated. There was ho irttention 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 kpeyv pf Malioni's preliminary rtsultSearly in 1973 but considered them to be as preliminary as did U.S. industry. At the Second Inter national Symposiutnron Cancefi election and Prevention in Bolsfenalijaly. 9 to 12 April 1973, Maltonj showed'a JaMe of pre liminary results linking vinyl 'chloride with cancer formation (which tvafs'nqt published until 1974) (J). Umberto Satlipui, asso ciate director of carcinogenesis at the Na tional Cancer Institute,'kvas present at the meeting and subsequenilydiseusscd the re sults with Maltoni.al-his Itallltflrlabt falory (4). Salliotti fell tbarsheWtfrtiijshptild be included in "a well documented; report".ta be assessed by a rcywwpanei;t|.fo'i>fAVi)rld Health Organi&jfion's international cent ra t io n s frequently .far above- current standards have not demonstrate! any car cinogenicity to humans." Thus the state ment by Edsall' thiit MCjAf... dppears to have deliberately deceived NIOSH regard ing the true facts" is inaccurate and mis leading. At.BERT C. Ct.ARK Manufacturing Chemists Association. 1825 Connecticut Avenue. NW. Washington, D.C. 20009 References S. T. R. Torkclson. F. Oven. V. K. Rowe. Am. tnd. Hvg A*\o* . J. 22. 254 <mi); R. II. Wilson. W. E. McCormick. C. F. Taiurn. J. L. Creech. J. Am. Med. Assoc 201. 577 (l%7); fc D BirclU. R. D. Slcwari. J. t. Mulchlcr. Am. inti. Hyg. Assoc. J. 3). 537 f 1969). 2. B. D. Diriman. W. A. Cook. W. M. Whilchousc. M. J Maynuson. T. Uncheck, Arch Environ Health 2!. M (1971); W. A. Cook, P. M. (iievcr. H. 1). I.'mman, II. J. Maynusun. ihid.. p. 74; V. N. Dot)* n. B. 1) Dinman. W, M Whilchousc. A. N. M. Nasr, H. J. Magnuson, ihul.. p. Hi. C. Ci. Kramer, ami J. F. Mulchlcr. Am Inti. Hvg. Assoc. J. 33. PI (1*372). 3. C. Maluini, Excerptu Med Ini Congr. Ser. No. : *5(1974). p. 4. 4. G Sallioiti, in U.S. Senate, Commillee on Com* mcrcc. Subcommittee on l.nvironniem. Vinyl ( il*ride (93rd Congress. 2nd session. 1974), on. 34 56. Reference* 1. Committee on Science and Public Policy. The Life Sciences (National Academy of Sciences. Wash- .. injgt(mvp.C.. I970). p.432. 2. G.'-Ntfcmure. Environment fSt. Louisl 14 (No. 6). 14(1972). 3. A. Slringcr. J. A. Pickard. C. H. Lvons. Festic.ScL 5,^7(1974). 4. F. vjortarty. NewSci. 53, 594 (1972). 5. J. L. Muinclink. R. C. Waybrant. R. C. Ball. Trans. An. Etsh. Sue. 100. 207(1971). 6. G. R. Harvey. Oceonus IX. 19(1974). 7. J. W. Kanwisher. "DDT in the marine environ ment" (chairman's draft of an ad hoc committee report. National Academy of Sciences. Washing ton. DC.. 1973); G. R.'Harvey. "DDT in the marine environment A review of present under standing" (draft of an ad hoc commtltee 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 dilferenl. 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- 174 sui NCE, VOL. tU'J 20028001 V duced by "repealed long-term high level exposures." The attitude expresset) in Clark's letter, however, illustrate', the ma jor point that caused concern to the 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 attitude 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 to 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 to appear in human subjects fcefore taking action. Fortunately the work of Ames el al. (/) and others has shown that carcinogens are generally mutagens. Screening of chemicais 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 orr mutagenicity tests should not be cause for complacency. Highly toxic substances may be nonmulagenic. I 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 1 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 to the references cited by Edwards a recent review on insecticides by Jukes (2) which contains a vigorous de fense of the value and safely 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 Stales was not arbitrary or capricious; it was taken after prolonged hearings, with presentation ol a profusion ol evidence bv both sides. The case for using DDT in countries where malaria is a serious prob lem is lar 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. lit JULY IMS The need of the future, however, is to de velop less persistent and more specili : pes ticides that can be directed against a nar row range of target species, while doing little or no damage to others. John T. Ki;sai i. Biological Laboratories, Harvard University. Cambridge. Massachusetts 021 Jfi References 1. B Amts F l) l.ccv W li. Durslon. Proc. .Nad Sci t'.V.-l 70. 7x2 (1973). 2. T. Jukc*. yutur*is.%cnu ha/lcrt 61, 6 (1974). Energy Equivalents The recent interest in alternative energy sources--in particular, energy derived from solid wastes -has prompted what may be described as a new parlor game of quoting energy equivalents of the new sources. For example, the potential of a new fuel is frequently quoted as the equiva lent of so many barrels of oil. implying that the new fuel could be so converted. The potential for deriving some form of energy from solid wastes expressed this way clearly ignores the laws of thermody namics. To avoid error and confusion. 1 propose a new vocabulary. 1 suggest that the product of the given mass of fuel. M. the heat of combustion. SHc, and the conversion factor. F, that is commonly used to express the energy value in barrels of oil (or some similar neuspeak unit) be termed the arithmetic equivalence, M\HCF, of the new source. This term could serve to alert audiences that scaling of new sources in such units docs not mean, nor imply, that the new source could physically or chemically be converted to the form described by the unit. Besides being used as a fuel directly (for example, in incineration) solid wastes may be converted to some other form by me chanical. chemical, or biological means to produce a unit of new fuel with a higher heat of combustion, SH'C. The conversion process will use energy, and the law of conversion of mass-energy dictates MSHe> M'SII'c where A/` is the mass of product fuel. Therefore, the conversion equivalence of feedstock M can be defined as M'SH'^F. Alternatively, the con version equivalence may be defined as the arithmetic equivalence less the energy in put and losses of the particular process. The two definitions of conversion equiva lence dilfcr slightly, particularly in ease of computation. However, the differences in value may not be great. The new fuel source may be used as a supplement to, or substitute for, a com monly used fossil fuel, with or without passing through a conversion process. Lxamples would be raising steam in an in cinerator using raw refuse, or in a suspen sion boiler designed for processed refusederived fuel, or using the fuel gas trom pyrolysis of solid wastes. In a given appli cation. the new form of fuel may operate with the same, greater, or lower cllicicncy than the fuel it is replacing. Thus the sub stitution equivalence is defined as the amount of fuel in the new form that must be used to replace the conventional fuel in a specific application. The substitution equivalence should be used as the basis for energy policy planning and not the arithmetic equivalence, as seemingly is done now. Harvks At.lt R ;\alional Center for Resource Recovery. Inc.. 1211 Connecticut Avenue. .YU'. Washington. D C. 200s6 Misplaced Research I wish to draw attention to the fact that Banting and Best worked al the University of Toronto and not at the University of Ontario, as indicated in Thomas H. Maugh's article on diabetes (Research News, 30 May. p. 920). A University of Ontario is nonexistent. Arthur M. Timms Conservation Council of Ontario. 45 Charles Street East. Toronto, Ontario M4Y 152 Sounds of Science This autumn quarter 1 will conduct, for the second time, a seminar entitled "Songs about science." 1 would appreciate dona tions of lyrics or music relating in any way to any area of science in its broadest sense. If you have taped or recorded material which you could reproduce, or if you want to sing or play some science songs. I will be pleased to send blank cassette tapes. There is relatively little professionally recorded music relating to science. Most science songs are written and performed by ama teurs (usually students and scientists); few of these are ever published or recorded and, in general, are rapidly lost. Frequently these amateur works provide penetrating commentaries on science and scientists. Thus I feel that this rare art form should be collected, preserved, and studied. John D. Shirks Department ofBiology, Universify of Utah. Salt Lake CityH4112 175 20028002