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LETTERS
iC ri/: |0ve~v7z u f
L ( ) R/Ul'o-'UC'A
Agency for Research on Cancer (of which
the United States is a member). This panel
Vinyl Chloride and DD F:
also considered Maltoni's data to be pre-
Environmental Klfctls
lirranars at dial time and "decided to post pone compilation of the definitive review
Tin- rcpori of the AAAS Committee on to the next meeting of the committee" (4).
Scientific Freedom and Responsibility, ab After a period in which epidemiological
breviated as an article by John T. Edsall and animal studies were being established,
(16 May, p. 6S7), requires comment. The MCA. on 17 April 1973. asked the Euro
section entitled "The case of data suppres peans to jointly make presentations to
sion concerning the carcinogenicity of vi U.S. and- European government author
nyl chloride" (p. 690) contains omissions ities. The Europeans readily agreed, and
and errors that are inconsistent with the on 15 June 1973. MCA called the National
committee's concern for scientific freedom Institute for Occupational Safety and
and responsibility. Since so much pertinent Health (NIOSH) and requested an oppor
information has been omitted concerning tunity to bring new information to that
this matter, readers may be misled into agency's attention. The appointment was
believing the report.
set by NIOSH for 17 July. Five European
Edsall states that, until May 1970. and American industry representatives
"there had apparently been no research in presented to NIOSH the information that
the plastics industry concerning the pos tumors had been found in animals exposed
sible hazards of vinyl chloride...." This is to vinyl chloride concentrations below
untrue. In fact, the basic published data on those that Viola had reported caused can
vinyl chloride toxicity came from Ameri cer in rats. At that time, no human cancer
can industry (/. 2). The information in (2) cases had been reported; therefore, no spe
had been publicly disclosed and presented cial significance could be attached to the
before their publication dales. Further types of tumors observed by Maltoni.
more. the investigations of Viola and of
The precautionary label suggested by
Maltoni have been supported by European MCA and referred to by Edsall was illus
industries.
trated in MCA's Chemical Safely Data
Edsall correctly states that Manufac Sheet (SD56) on vinyl chloride, revised in
turing Chemists Association (MCA) mem April 1972. Section 10.1 on "Health haz
ber companies entered into an agreement ards" refers to Viola's published studies.
with the European sponsors of Maltoni's The Data Sheet states. "Recent research
work not to reveal preliminary Italian studies reported from Italy indicate that
data. The agreement was not dissimilar to repeated, long-term high level exposures of
those commonly made between American rats to vinyl chloride monomer vapor can
sponsors (government, industry, and aca result in the development of malignant tu
demic) and research institutions that new mors. However, many years of industrial
data remain the property of the institution experience with human exposures to con
and that final results be disclosed through centrations frequently far above current
proper scientific channels when a study is standards have not demonstrated any car
completed and evaluated. There was no in cinogenicity 'o humans." Thus the state
tention of withholding adverse data. Under ment by Edsall that MCA ". . . appears to
MCA rules, all data developed under its have deliberately deceived NIOSH reeard-
auspices must be promptly reported pub ing the true facts" is inaccurate and mis
licly. Without exception, this has been leading.
done with all data on vinyl chloride.
Ai.bhrt C. Clark
U S. government scientists knew of Manufacturing Chemists Association.
Maltoni's preliminary results early in 1973 1X25 Connecticut A venue. NW,
but considered them to be as preliminary Washington. D C. 20009
as did U S. industry. At the Second Inter
national Symposium on Cancer Detection
Reference*
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 Salliotli, 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). Salliotli leit that the work should be included in "a well documented icporl" to be assessed by a teview panel of the World Health Organization's International
I. T. R. Torkclson. |-\ Oven. V. K Rowe. Am !nd.
Ilvg Assoc. J 22. 354 (I`Ml). R. II. Wilson. W. F.
McCormick, t F. Tatum. F F Creech, J Am.
Med As sue 201. 577(1907). F f) Karelia. K D.
Sic vart. J F. Mutchlcr, Am InJ
Assoc J.
3 ), 537 (1WI)
2 H I) Dinnun. W A.Cook.VV M. Whnchouse. li
J Mugnuhon. I Diuhcck. An h httvtrun Health
2 !. M I 19? | >,
A C wok. P. M (never ii D.
Finm.in. II J. Magnusmi, thul , p 74. V N l)o*J-
>. n, M It Dmman. VV M Whitchuusc. A N. M.
Saxr, H J MugiHJMKi, that. p N 1. ( G Kramer,
.`ul J. I M ulchlcr, A m hui II /* .4 mu' J 33. IV
(1772)
3 i Maltoni, t.xcerfnu MeJ int ( oit)(r Ser .Vo
M IV 74). p 4.
4 <i S.illtwni. m I) S Sen ae. Committee on C mu-
oil me. SuhLoinmilu- on I nvironmem. Vinvl
( th-riJc (Vlrd Congress. 2nd session. IV/4). pp.
'4 50.
fp, .> *- n t >. .< v. ,
' rr
John T. Edsall errs in crediting DDT
with hailing a cholera epidemic in Naples
during World War II. A National Acad
emy of Sciences committee stated :n 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 ihe! Edsall selected an
undergraduate student s term paper (-') as
"a useful short history of the use of DDT,"
for several well-informed scientists have written articles and hooks 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. (J) found the half-life of DDT to be only 3 years in orchard soil after 17 successive years of heavy spraying. Edsall cites DOT'S "pro gressive concentration in food chains" as having "led to .he 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 Morittrty (4). Hamelink el al. (5). 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" a.e again seeking to hail all DDT exports from the United States. It is encouraging to see no such proposals in the
AAAS committee report. J. Gordon Edw ards
Department ofBiological Sciences,
San Jose State University, San Jose, California 95192
References
1. Committee on Science and Public Policy The Life Science* (National Academy of Socntts, Wash ington. D C.. 1970). p. 432.
2. G. Mclntire. Environment iSt. Louis, 14 (No. 6). 14(1972).
3. A. Strinuer. J. A. Pickard. C. H. L\un\. Pesttc. Sci. 5. ;K7 (IV74).
4. F. 1or>jri>. AVk-Sci. 53. 5V4 (IV72). 5. J. F. Hamelink. R. C. Wavbruni. K C. Rail. Trans.
An. hish ,Vw. 100, 207(197)). 6. G. R Marses. Ocranus IS. IV <iv?4). 7. J W. Kanwisher. ``DDT m the marine environ
ment" (chairman's dralt of an ad hoc committee report. Nalionai Academy ol Sciences. Washing ton, DC., IV73): G. R. Harvey "DDT in the marine environment A review ol present under standing" (dralt of an ad hoc committee report. National Academy of Sciences, A ashingion. I).C, IV73).
I am glad to note that, as Clark's letter points out. there was research hv Ameri can industry on the toxicity of vinyl chlo ride, beginning several years belore 1970. In this work, however, what have proved to he the major hazards were not discovered; if they had been, the later story would have been scry dillcrcnl. 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-
H SC ll M I , SOL. J S')
i
duced by "repeated long-term high level exposures." The altitude expressed in Clark's letter, however, illustrates the ma jor point that caused concern to the Com mittee on Scientific Freedom and Respon sibility. I he 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 largt 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 far the cancers to appear in human subjects before taking action. Fortunately the work of Ames el al. (/) 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.
I thank Edwards and others for correct ing the erroneous state.'.ient 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 to 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 alter prolonged hearings, with presentation of a prolusion of evidence by
both sides, flic case for using DDT in countries where malaria is a serious prob lem is l.ir stronger. I o iny knowledge there is no adequate substitute for the spraying of interior walls of houses with 1)1) I 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.
The need of the future, however, is to de monly used fossil fuel, with or without
velop less persistent and more specili.: pes passing through a conversion process. Ex
ticides that can he directed against a nar amples would be raising steam in an in
row range of target species, while doing cinerator using raw refuse, or in a suspen
little or no damage to others.
sion boiler designed for processed refuse-
T.John
Edsai.i.
derived fuel, or using the fuel gas Irom
Biological Laboratories.
pyrolysis of solid wastes In a given appli
Harvard University.
cation. the new form of fuel may operate
Cambridge. Massachusetts 02138
with the same, greater, or lower efficiency
References
1. B Ames. K L) I.cc. W. t. Durston. Proc. Sail. Sci. IW.-1.70. 7*2(1^73).
2. T. Jukes. Stiturwisscnschajun 61. 6( 1974).
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
Energy Equivalents
arithmetic equivalence, as seemingly is
done now.
The recent interest in alternative energy
Harm v An hr
sources--in particular, energy derived .Sational Center for Resource Recovery.
from solid wastes --has prompted what Inc.. 1211 Connecticut Avenue, .YU'.
may be described as a new parlor game of Washington. D C. 200s6
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 Misplaced Research
that the new fuel could be so converted.
The potential for deriving some form of I wish to draw attention to the fact that
energy from solid wastes expressed this Banting and Best worked at the University
way clearly ignores the laws of thermody of Toronto and not at the University of
namics. To avoid error and confusion, I Ontario, as indicated in Thomas H.
propose a new' vocabulary .
Maugh's article on diabetes (Research
I suggest that the product of the given News, 30 May. p. 920). A University of
mass of fuel. M. the heat of combustion. Ontario is nonexistent.
AW,. and the conversion factor. F, that is
Arthur M. Timms
commonly used to express the energy Conservation Council of Ontario.
value in barrels of oil (or some similar 45 Charles Street East.
newspeak unit) be termed the arithmetic Toronto. Ontario M4Y 152
equivalence, M2sHf. of the new source.
This term could serve to alert audiences
that scaling of new sources in such units
does not mean, nor imply, that the new Sounds of Science
source could physically or chemically be
converted to the form described by the This autumn quarter 1 will conduct, for
unit.
the second time, a seminar entitled "Songs
Besides being used as a fuel directly (for about science." 1 would appreciate dona
example, in incineration) solid wastes may tions of ly rics or music relating in any way
be converted to some other form by me to any area of science in its broadest sense.
chanical. chemical, or biological means to If you have taped or recorded material
produce a unit of new fuel with a higher which you could reproduce, or if you want
heal of combustion. A//',. The conversion to sing or play some science songs. I will be process will use energy, and the law pleased to send blank cassette tapes. There
of conversion of mass-energy dictates is relatively little professionally recorded A/A//, c A/'A//', where A/' is the mass of music relating to science. Most science
product fuel. Therefore, the conversion songs are written and performed by ama
equivalence ol leedslock A/ can be defined teurs (usually students and scientists); few
as A/'A/FF. Alternatively, the con of these are ever published or recorded
version equivalence may be defined as the and, in general, are rapidly lost. Frequently
arithmetic equivalence less the energy in these amateur works provide penetrating
put and losses of the particular process. commentaries on science and scientists.
The two definitions ol conversion equiva Thus I feel that this rare art form should
lence diller slightly, particularly in ease ol be collected, preserved, and studied.
computation. However, the dillercnces in
John I). Srixi s
value may not be great.
De/tarlmcm i>l biology.
I he new fuel source may be used as a University of L 'tali.
supplement to, or substitute lor, a com Sail Lake City 84112
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