Document 3N17KZ6r0rZwR1NDZmwJee3K6

i) f " munologically. In addition to RSVo, nooinfectious forms of mouse sarcomateukcmia virus have been reported to have very low levels of DNA polyirw erase {13). None of the infectious forms has been found deficient in this enzyme. H. Hanafusa Public Health Research Institute of the City of New York, New York 10016 D. Baltimore, D. Smoler Department of Biology, Massachusetts Institute of Technology, Cambridge 02139 K. F. Watson, A. Yaniv S. Spiegelman Institute of Cancer Research, Department of Human Genetics and Development, Columbia University College of Physicians and Surgeons, New York 10032 Reference and Note* f. H. Hanafusa and T. Hanafusa, Virology X, 630 (1968). . 2. T. Hanafusa, H. Hanafusa, T. Miyamoto, Proc. Sat. Acad. Sci. U.S.A. 67, 1797 (1970). 3. H. Hanafusa and T. Hanafusa, Virology 43. 313 (1971). 4. W. S. Roblntoo and H. L. Robinson, Ibid. 44, 457 (1971). 3. D. Baltimore and D. Smoler, Proc. Nat. Acad. Set. VS.A. 6ft, 1507 (1971V 6. S. Spiegelman, A. Bumy, M. R. Das, 3. Keytar, 3. Schlom. M. Travnicek, K. Watson, Nature 226, 430 (1970). 7. Abbreviations : Poly(A), polyadenylate: poly(C), polycytldylate; poly(dT), polydeoxythymidy* late; poly(dG), polydeoxyguanylate; dTMP. deoxylhymJdine monophosphate; dTTP, dc* oxythymidine triphosphate; dATP, deoxyadenotine triphosphate; dGTP, deoxypurmotine trJ- phosphate; dCTP. deoxycytidioe triphosphate; IfO, immunoglobulin Q. . L. A. Locb. A Blot. Chem. 244, It 72 (1969). 9. K. F. Watson, R. C. Nowinskl. A. Yaniv, S. Spiegelman. i. Virol.. In press. 10. R. C. NowinskJ, K. F. Watson, A. Yaniv, S. Spiegelman, in preparation. 11. D. L. Kacian, K. F. Watson, A. Bumy, S. Spiegelman, Biochtm. Biophys. Acta 246, 365 (1971). 12. A. Weissbach, A. Bolden, R. Muller, H. Hanafusa, T. Hanafusa, /. Virol., in press. 13. P. T. Peebles, D. K. Haapala, A. F. Oazdar, Ibid. 9. 488 (1972). 14. S. Spiegelman, A. Bumy, M. R. Das, J. Keydar, J. Schlom, M. Travnicek, K, Watson, Nature 227, 3 (1970). 15. We thank Dr*. A. J. Langlols and D. and J. W. Beard for supplying avian myeloblastosis virus. Wc alto thank Dr. R. NolniU for assistance In preparing antiserum against purified AMV DNA polymerase, and Dr. T. Hanafusa for various viruses. Supported by NCI grants CA*08?47 and CA-02332 from the contracts from the Special Virus Cancer Program of NCI (including 70*2049 to the Institute of Cancer Research). 6 July 1972; revised 12 August 1972 Polychlorinated Diphenyl Residues: Accumulation in Cayuga Lake Trout with Age of -their age, length, and weight. The correlation coefficient for PCB con centration as a function of age was 0.86 and was highly significant. The corre lation coefficients relating PCB concen tration with length and weight for fish 2 years and older were 0.85 and 0.S0, respectively. The weights and lengths of the year-old trout were not recorded. The relation between the cone, ntration of PCB's in the lake trout and their age is shown in Fig. I; the curve rep resents the best fit of the data and has the equation: PCB = 1.031 where a is age. Figure 2 shows gas chromatograms of PCB's in a 12-yearold lake trout and of Aroclcr 1254 standard (a mixture of chlorinated bi phenyls containing 54 percent chlorine) to illustrate the similar peak retention times. The_relatiye peak heights of in dividual PCB isomers in the chromatogram did not vary witTTage of the fish". This would indicate that there is no selective metabolism or storage oTspe^ ctlic PCB isomers as the fish mature. Combined gas chromatography- mass spectrometry was used to verify the presence of the various PCB isomers in a 12-year-old lake trout (PCB's. 26.2 Abstract. The concentration of polychlorinated biphenyls was shown to pro gressively increase with maturity in a series of lake trout. The presence of these compounds was determined by column chromatographic isolation, specific de tector gas chromatography and mass spectrometry. The relation between fish age and the concentration of polychlorinated biphenyls was highly significant. Residues of polychlorinated biphenyls (PCB's) have been reported in fish (/), and general environmental contamina tion by these compounds has been re viewed (2). The concentration of DDT residues in a scries of lake trout from Cayuga Lake in Ithaca, New York, was found to be proportional to their age (3). Since PCB's are similarly stable, fat-soluble compounds, analysis for them was performed on the same series of fish. The fish were netted in October 1970. Their ages were accuraicly known, because the fish are annually stocked as yearlings and distinctly marked as to year class. Without evisceration, each fish was mechanically chopped, ground, and thoroughly mixed. Fish samples (5g) were dried and extracted with hexane in a Soxhlet apparatus for 3 hours. The hexane extracts were con centrated, and PCB's were separated from DDT residues and other constitu ents by adaptations of the methods (4) involving sulfuric acid partitioning and column chromatography on silica gel. Final analysis was made by electron af finity gas chromatography with a col umn 30 cm long, consisting of 10 percent DC-200 on 100- to 120-mesh Gas-Chrom Q and operated at 185C. The concentration was estimated by the method of Risebrough (5), in which the response of each PCB isomer is taken as equal to that of the correspond ing weight of p.p'-dichlorodiphenyldichloroethylene (p.p'-DDE). This meth od was sensitive to about 0.25 part per million (ppm) of PCB's in the fish. Analysis of PCB's in five portions of the same fish were 6.4, 6.0, 5.6, 5.6, and 5.3 ppm. The standard deviation for these analyses is 0.427. Table I lists the concentrations of PCB's in the lake trout as a function Table 1. Residues of PCB's in Cayuga Lake trout as a function of maturity; J, jmerlile. Age (years) Length (cm) Weight PCB (8) fppra) tj 1j 1j 1j 2j 2j 2j 3j 3j 3j 4j 4J 4j 5M 6M 6M 6F 7M 7M 7 8F 8M 8F 9F It M 12 M 12 M 12 F 27.7 28.7 33.5 44.5 44.5 41.1 53.8 50.3 55.1 61.0 63.5 66.4 68.3 63.5 68.9 59.7 75.2 71.4 69.0 71.2 80.3 71.6 75.5 70.6 181 226 407 815 725 770 1310 1160 1359 2030 2440 2850 2310 2260 3300 1990 3390 2805 3300 3390 4200 2535 3120 3440 0.6 1.6 0.5 1.2 20 1.3 2.5 2.2 2.4 1.2 3.5 41 5.1 5.7 3.4 9.7 8.6 4.0 55 10.5 17.5 13.4 4.5 .30.4 12.4 13.4 26.2 7.4 29-SLTTrMBER 1971 DSW 026553 1191 STLCOPCB4010514 fish may be due to greater differences among foraging, metabolic, and excre tory capabilities of these older fish. Cmu. a. Bache Pesticide Residue Laboratory, Cornell University, Ithaca. New York 14850 James \V. Serum Department of Chemistry, Cornell University William D. Youngs Department of Natural Resources, Cornell University Donald J. Lisk Pesticide Residue Laboratory. Cornell University Refmarts sad Note* 1. J. H- Koemin, M. C. Ten Noever De Brauw, R. H. DeVot, Nature 221. H2S (1969), S. Jensen, A. G. Johnels, M. Olsson, G. Otterlind, Ibid. 22*. 2*1 (1969): V. Zitlo, But! Environ. Cantam. Toxicol 6 464 (1971) 2. D. B. PeaJutJ and J. L. Linar, BMcitnee , 958 (1970); A. L. Hmmond, Science ITS, 155 (1972). 2- W. D. Youngs, W. H. Gutenmtnn, D. I. Lisk, Environ. Sci. Ttchnol. 4, 451 (1972). 4. D. L. Grant, W. E. J. Phillips. D. C. VIDeneuve, Bull. Environ. Conlam. Toxicol. 4, 102 (1971); D. Snyder and R. p :ineiL Ibid., p. 385. 5. R. W. Rlsebrouih. In Chemical Fallout, M. W. Miller and G. G. Berg. Eds. (Thomas, Springfield, III., 1969), pp. 5-23. 6. We thank G. A. Maylin for allowing use of tbe mass spectrometer. JO June 1972 - Atmospheric Carbon Dioxide: Its Role in Maintaining Phytoplankton Standing Crops Fig. 1. The concentration of PCB's in Cayuga Lake trout as a function of age. ppm). The mass spectra obtained from both a Perkin-Elmer 270 and a Finnigan 1015 quadrapole gas chromato graph-mass spectrometer were essen tially identical with the mass spectra of the corresponding isomers of Aroclor 1254 standard. There are many sources of PCB's in the environment, and it is not known what combination of these leads to con tamination of Cayuga lake trout.._Xhe^ increase in PCB concentration with trout~gEe~is the same trend noted Jor DDT residues in this scries of fish. The larger variation'in PCB concentrations among individual 11- or 12-year-old Ralintioft bm (min) Fig. 2. Gas chromatograms of a 12-yearold Cayuga Lake trout (injected sample represents 0.12 mg of fish) and 1 ng of Aroclor 1254 standard. Abstract. The rate of invasion of carbon dioxide into an artificially eutrophic Canadian Shield lake with insufficient internal sources of carbon was determined by two methods: measuring the carbon : nirrogen : phosphorus ratios of seston after weekly additions of nitrogen and phosphorus, and measuring the loss of radon-222 tracer from the epilimnion. Both methods gave an invasion rate of about 0.2 gram of carbon per square meter per day. The results demonstrate that invasion of atmospheric carbon dioxide may be sufficient to permit eutrophi cation of any body of water receiving an adequate supply of phosphorus and ni trogen. The atmosphere is frequently con sidered to be an insignificant source of CO- for phytoplankton production (/). Yet, by adding phosphate and nitrate we have been able to increase by almost two orders of magnitude the standing crop of phytoplankton in a small Cana dian Shield lake which has extremely low concentrations of natural dissolved inorganic carbon (less than 0.6 mg/ liter in the cpilimnion in midsummer). The lake appears to have obtained the carbon necessary to produce the alga! bloom from the atmosphere (2, 3). We report here measurements of the inva sion rate of atmospheric CO- into the waters of this experimentally enriched lake. The results were obtained between 4 and 18 August 1970. Lake 227, a small oligotrophic lake in the experimental lakes area of the Fisheries Research Board near Kenora, Ontario, was enriched with 0.34 g of phosphorus (as Na-HPOj) and 5.0 g of nitrogen (as NaN03) per square meter per year in 1969, and 0.48 g of phos phorus (as H-,P04) and 7.2 g of nitro gen (as NaN03) per square meter per year in 1970. The chemical additions were made in 17 weekly increments in 1969 and 21 weekly increments in 1970. The midsummer phytoplankton standing crop, as measured by chloro phyll a concentrations, increased from 1 to 3 jg/liter in 1968 (before fertiliza tion) to 50 to 100 /eg/liter after the additions. The uptake of CO- by this phytoplankton caused an increase in the pH of the euphotic zone from normal values of 6 to 7 to values ranging from 9.5 to 10.2 during summer, so that very little of the dissolved inorganic car bon was present as gaseous CO- (2, 3). The concentration of dissolved inorgan ic carbon (ICO- = CO- + HC03~ +C03:-), however, did not change great ly after fertilization. The midsummer concentrations of total CO- in the epilimnion ranged from 20 to 50 pmole/liter (0.24 to 0.60 mg/liter). As a result of the high pH and low con centration of CO-, the partial pressure of CO- in cpilimnetic waters (calculated from the pH, total CO- concentration, and temperature) was far below that of the atmosphere (Fig. 1): this created a pronounced concentration gradient from ihe atmosphere inlo ihe lake. It is impossible to calculate the magnitude of CO- exchange between the atmosphere and the water from the difference in partial pressures alone. 1192 SCIENCE, VOL. 177 DSW 026554 STLCOPCB4010515