Document 4JpkXEV8eOwxg1gv7onrxmgMV

Scientist in the Senate Constance Holden (News and Com* ment, 18 May, p. 720) wrote (hat there is only one scientist in Con* gress--Mike McCormack (D-Wash.), a chemist. Locke White, Jr., writes (Let ters, 3 July, p. 112) that another sci entist. James O. Martin (R-N.C.). former associate professor of chemis try at Davidson College in North Caro lina, is also in Congress. I would like to bring to your attention a third scien tist in Congress, Senator Dewey F. Bartlett (R-Okla.). Bartlett was a practicing geologist in Oklahoma for many years until he became governor of Oklahoma, and then senator. He is still an outstanding geologist. A. A. Meyerhoff American Association of Petroleum Geologists, 1444 South Boulder, Box 979, Tulsa, Oklahoma 74101 Some 02 more expensive.. None are more reliable ' Buchler Flash Evaporators Bom* Hath bvapontom look Ilka our* but thay don't oflar tha aama banaflta. For In- aaal provtdaa a waaiMm tloM mtam tor raUablllty andmtntowm woar. wiwra mora, uolilar Ftaah Evaporator*oa* laaa. And you can ohooaa Irani a wioa vanaif or mooan Inoludlng wutobto tpand. tor batobtyp* operation* or oonHnuoua Row. Contact ua tor a oomprabanalva broohura. Buchlar Inatrumanta Olvialbn of Saaito 1327 Slxtaanth Stiaat . Fort Laa, Now Jaraay 0701^ Ckda Ma. a Iwdtn' farriw Thomas H. Maugh Il's re port "DDT: An unrecognized source of polychlorinated biphenyls" (Research News, II May, p. 378) deals with vapor-phase photolysis, it gives the mis leading impression that such a reaction pathway is novel and ignores earlier published research. DDT (1,1,1 -trichloro-2,2-bis( p-chlorophenyl) ethane | was certainly recognized as a source of polychlorinated biphenyls (PCB's) by 1969. Jt is correct that Guenzi and his as sociates (7) did not observe the forma tion of PCB's or DDMU 11 -chloro-2,2bis(p-chlorophenyl)ethylene) by photol ysis of solid DDT or DDT in hexane after irradiation at 233 nanometers. However, in 1969 we clearly showed (hat DDMU, dichlorobenzophenone, and dichlorobiphenyl were products of DDT or DDE (l,l-dichloro-2,2-bis(pchiorophenyl)ethylene| photolysis in methanol at 260 nm (2). Moreover, we investigated the photolysis of di chlorobenzophenone and reported that 4,4'-dichlorobipheny! (a PCB) was one of the photoproducts. Our proposed re action schemes were supported by the identification of many products derived by a series of radical reactions. Among the products was 3,6-dichlorofluortnone, which we had reported as a major photolysis product of DDE in 1969 (J). We also found that photo oxidation of this compound to 3,3'-dichlorobiphenyl-2-carboxylic acid oc- SCtENCE. VOL. INI MONS 086605 4 tl tl currod. Subiequent decarboxylation of this add could yield traces of PCB's, u could the decarbonylatlon of trichlorobenaophenone (also reported by us as photolysis product). The expert mental work reported in the two pub* licatJons cited indicated dearly that some PCB's were products of DDT photolysis. The suggestion that a pro portion of the PCB's in the environ* ment might result from photodecom* position by DDT was voiced by Peakall : and Uncer (4) in 1970. However, they ; were of the opinion that, since PCB's . extracted from biological material re sembled the more highly chlorinated I members of this class, it was highly un* ' likely that PCB's found in the environ ment were derived from other chlori* natad pesticides. Nisbet and Saroftm (5) stated that a large proportion of the PCB Isomers with four or fewer chlo rine atoms are missing from animal samples indicating that these have been degraded in the environment. I Jack R. Plimmek 1 Utb 1. Klingebibl I Pesticide Degradation Laboratory, Agricultural Environmental Quality Institute, Agricultural Research Service, Beltsvllle, Maryland 20705 Miami 1. A. R. Metier, W. D. Gucnzl, L. L. Milter, Sehnt* M4. I0SS (ISM). 2. J. R. Plimmer. U. I. Kllnazblel, a. . Hum, mm, Sctenc* 1ST, 67 (1970). J. |, a. Pllmmcr utd U. 1. Klinsebiel, Chrm. CewMiaa. (1949), p. 641. 4. O. a. Pnksll end j. L. Linear. BtoSelenc* sa, asa (1970). 5. C. T, NIzbM and A. F. Seroltm, Environ. Hrmtih Ptnptvt. Bsperimenial Imw Nn. I <1972), p. 21. mal that happens to have been ex posed to DDT and Demeton should lead to the conclusion that these chem icals induce malignant tumors in monkeys. Unfortunately, these deductions are very often made, but, unless controlled studies with more animals are con ducted, one has to assume that the gastric lesion observed in this one rhesus monkey developed spontane ously. Seven additional rhesus monkeys of about the same age that we studied did not develop the same lesion even though they had also been exposed to DDT and Demeton. Rbnate D. Kimbrough Bioeffects Branch, Environmental Protection Agency. Chambiee. Georgia 30341 Miwfn I. R. Kimbrough. Arch, rathot. SI. 343 (1946). Comet Formulas In his article "The 1972 Nobel Prize for Economic Science" (Research News, 3 Nov. 1972, p. 487) Paul Samuelson states that "relative factor shares in GNP" according to Sir John Hicks is a, s V,dQ{y)/*V, where V, is an input factor of produc tion (for example, labor) and Q is the total output. Actually this is not the "relative factor share" but the "total factor share" received by the factor V,. Thus, the relative factor share is Mlli|asiN Tumors in Monkeys Edwin J. Andrews (Letters, 20 Apr., p. 2SS) and J. R. Allen and D. H. Norback (p. 2S6) refer to a spontaneous malignant gastric tumor in a rhesus monkey that 1 reported several years ago (7). This rhesus monkey had in gested DDT as well as Dcmcton during certain periods of his life. In both letten il was pointed out that the described lesion occurred in response to exposure to DDT and Demeton. When I reported this lesion, 1 con cluded that the development of the tumor was spontaneous rather than re lated to the exposure to pesticides. This same monkey had been in a poliomyelitis study and, in addition, had periodically been given 5 percent alcohol solutions. 1 do not think that the observation of a lesion in one ani- 14 SBFTKMBER 1973 Manoucher Parvin Hunter College of the City University of New York, New York 10021 1 am grateful to Parvin for pointing out the typographical error in the fac tor-share formula. The correct version of the formula appears later in my article, so no informed reader should have been misled. Another typographical error in my article should also be corrected. The equation involving Hick's net demand functions should read 0 = -- F[P) = - U,[p............. .... - - Fix p] Paul A. Samuelson Department of Economics, Massachusetts Institute of Technology, Cambridge 02139 HONS 086606 CUUm Ha. 94 am BamOan' totta Cmr4 999